Board Game Arena - User contributions [en]

Tutorial reversi

2022-06-11T20:55:50Z

VKV FR: Added a reason why those methods must be added.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, this.player_id );" in the "setup" Javascript method in reversi.js, and restart the game.
''Note: if the page fails to load with a "Javascript error: n is null" message, make sure you have added the "tokens" div in your template as instructed above.''

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Insert the following code ''between "// TODO: setup the initial game situation here" and "// Activate first player":''
:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game - this line is already present in the default code template.

As already instructed in the previous section, you need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload).
Add the following lines in the "getAllDatas" method, after "// TODO: Gather all information about current game situation (visible by player $current_player_id).".

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes. We add it to the result associative array with the key 'board'.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn: referenced in the "args" property of the "playerTurn" state; this is the name of the method to call to retrieve arguments for this gamestate. Arguments are sent to the client side to be used on "onEnteringState" or to set arguments in the gamestate description.
* stNextPlayer: referenced in the "action" property of the "nextPlayer" state; this is the name of the method to call when this game state become the current game state.

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-11T11:41:11Z

VKV FR: Undo revision 13553 by VKV FR - It's already all squares that we are going through, not always tokens.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, this.player_id );" in the "setup" Javascript method in reversi.js, and restart the game.
''Note: if the page fails to load with a "Javascript error: n is null" message, make sure you have added the "tokens" div in your template as instructed above.''

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Insert the following code ''between "// TODO: setup the initial game situation here" and "// Activate first player":''
:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game - this line is already present in the default code template.

As already instructed in the previous section, you need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload).
Add the following lines in the "getAllDatas" method, after "// TODO: Gather all information about current game situation (visible by player $current_player_id).".

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes. We add it to the result associative array with the key 'board'.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-11T11:39:48Z

VKV FR: Clarify sample source code.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, this.player_id );" in the "setup" Javascript method in reversi.js, and restart the game.
''Note: if the page fails to load with a "Javascript error: n is null" message, make sure you have added the "tokens" div in your template as instructed above.''

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Insert the following code ''between "// TODO: setup the initial game situation here" and "// Activate first player":''
:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game - this line is already present in the default code template.

As already instructed in the previous section, you need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload).
Add the following lines in the "getAllDatas" method, after "// TODO: Gather all information about current game situation (visible by player $current_player_id).".

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes. We add it to the result associative array with the key 'board'.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var token = gamedatas.board[i];

if( token.player !== null )
{
this.addTokenOnBoard( token.x, token.y, token.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-09T19:40:35Z

VKV FR:

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, this.player_id );" in the "setup" Javascript method in reversi.js, and restart the game.
''Note: if the page fails to load with a "Javascript error: n is null" message, make sure you have added the "tokens" div in your template as instructed above.''

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Insert the following code ''between "// TODO: setup the initial game situation here" and "// Activate first player":''
:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game - this line is already present in the default code template.

As already instructed in the previous section, you need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload).
Add the following lines in the "getAllDatas" method, after "// TODO: Gather all information about current game situation (visible by player $current_player_id).".

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes. We add it to the result associative array with the key 'board'.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-09T19:34:52Z

VKV FR: Precision about source code to add.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, this.player_id );" in the "setup" Javascript method in reversi.js, and restart the game.
''Note: if the page fails to load with a "Javascript error: n is null" message, make sure you have added the "tokens" div in your template as instructed above.''

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Insert the following code ''between "// TODO: setup the initial game situation here" and "// Activate first player":''
:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game - this line is already present in the default code template.

As already instructed in the previous section, you need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-08T20:49:05Z

VKV FR: Corrected a line of code. Added clarification in case of error.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, this.player_id );" in the "setup" Javascript method in reversi.js, and restart the game.
''Note: if the page fails to load with a "Javascript error: n is null" message, make sure you have added the "tokens" div in your template as instructed above.''

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Troubleshooting

2022-06-08T20:37:46Z

VKV FR: Adding a new error message.

Describing common errors which is hard to understand and debug

__TOC__

== Game does not start at all ==

=== Undefined offset: 0 in table/table.game.php on line 1417 ===

Do not call self::getActivePlayerName() during setupNewGame()

Ensure you're calling $this->gamestate->changeActivePlayer() at the end of your game setup. You must always have at least one active player.

=== Javascript error: During pageload n is null ===

When calling dojo.place(), the name of the container (second parameter) to place the new block into is not defined in the page template.

=== Unexpected error: Wrong formatted data from BGA gameserver 1 (method: createGame): ... ===

This is generic message usually followed by exact position in your source code, and usually its syntax error in one of yours php script

=== Unexpected error: Propagating error from GS 1 (method: createGame): Fatal error during yourgame setup: Not logged ===

Calling self::getCurrentPlayerId () or using $g_user from 'args' state function, see also below

=== Unexpected error: Propagating error from GS 1 (method: createGame): Fatal error during yourgame setup: Unknow player statistic: ===

Calling self::incStat() with second parameter which is an empty string

=== Unexpected error: Propagating error from GS 1 (method: createGame): Fatal error during yourgame setup: Error while processing SQL request: INSERT INTO stats ... ===

Fatal error during yourgame setup: Error while processing SQL request: INSERT INTO stats (stats_type, stats_player_id, stats_value) VALUES ('10','2300663','0'),('10','2300662','0')
Duplicate entry '10-2300663' for key 'stats_table_id'

Why? In the stats.inc.php you declared two keys with the same integer "id"

=== Unexpected error: Propagating error from GS 1 (method: createGame): Fatal error during yourgame setup: BGA main website do not respond ===

Check if other games work; if not, it's a problem with BGA Studio; if so, your game likely reaches an end state immediately. Check your states.inc.php and your transitions.

=== Unexpected error: Propagating error from GS 1 (method: createGame): BGA service error ===

You may have a syntax error in your dbmodel.sql.

Or, you may be calling self::initStat() for a statistic that does not exist. Check the statistic name, and make sure you clicked "Reload statistics configuration" button in the admin console after making changes to stats.inc.php

Or you may not have your states.inc.php set up correctly.

You may have an error in your table.game.php file in setupNewGame (such as <code>$result['x'] = y;</code> when $result is not an array).

=== Unexpected error: Table status of a starting game should be 'setup' ===

This error message appears when you start a one player game using the "Express Start" button.

In normal situation, the game starts just after this message and everything should works normally. In this case, you can just ignore this message.

If the games does not start, it is most probable that there is a syntax error in any of your php code (Check your states.inc.php and X.game.php)

=== Fatal error during creation of database ebd_quoridor_389 Not logged ===

Check that you didn't use $g_user or getCurrentPlayerId() in setupNewGame() function or in an 'args' function of your state.

As these functions are not consequences of a user action, there is no current player defined.

As a general rule, you should use getActivePlayerId() and not getCurrentPlayerId(). See the [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine presentation on the game state machine] for more information.

=== Warning: Invalid argument supplied for foreach() in table.game.php ===

Warning: Invalid argument supplied for foreach() in /var/tournoi/release/tournoi-151226-1240-gs/www/game/module/table/table.game.php on line 129
Fatal error: Cannot unset string offsets in /var/tournoi/release/tournoi-151226-1240-gs/www/game/module/table/table.game.php on line 143

That appears when your arg* function that suppose to return array of state arguments returns a scalar (a non-array) value

=== The server reported an error ===

During table creation: "The server reported an error" error shown and nothing else.

If you cannot even create a table - there is syntax error in gameinfos.php, check it, reload it from management panel.
If still no luck copy clean version from template https://github.com/elaskavaia/bga-sharedcode/blob/master/gameinfos.inc.php

=== Unexpected Error : Invalid player number for this game : 4 ===

This error may comes when trying to change the player number configuration in gameinfos.inc.php from a higher to lower number of players (for example from 4 to 2).

The following steps will help to change a player config from array(4) to array(2) :

* change in gameinfos.inc.php the entry to 'players' => array( 2,3,4 )
* In game management page (Control Panel > Manage Games > "Your Game"), press the "Reload Game information" button
* create a new table
* reduce the number of players to 2 and start the game
* (express) Stop the game
* change in gameinfos.inc.php the entry to 'players' => array( 2 )
* press again the "Reload Game information" button

=== Blank page ===
If you see no html at all check
* if you have syntax error in your view.php file
* class name of your view.php file does not match the project name (should be view_foo_foo if project is foo)
* game name return by getGameName() does not match the project name (should be "foo" if project is foo)

class view_russianrailroads_russianrailroads extends game_view {
function getGameName() {
return "russianrailroads";
}

== Game starts but I can't make a move ==

=== When I do a move, I got "Move recorded, waiting for update ..." forever ===

"Move recorded" means that your ajaxcall request has been sent to the server and returned normally.

"Waiting for update" means that your client interface is waiting for some notifications from the server that correspond to the move we just did.

If this message stays forever, it is probably that your PHP code does not send any notification when the move happens, which is abnormal. To fix this: add a notifyAllPlayers or a notifyPlayer call in your PHP code.

=== When I do a move, I get "Sending move to server..." then nothing and game resets to state before the move ===

Its possible that server code get into infinite loops or thinks too much, in which case it will timeout and will be aborted without any extra logs (and db transaction you saw in the log won't be committed). You will usually see "Unable to connect to server" message on console in this case. You have to put more logging into server
to trace where it hangs.

=== When I do a move, I get "Ajaxcall error: empty answer" ===

You either have missing self::ajaxResponse(); in your [[Players actions: yourgamename.action.php|game.action.php]] method, or there is some problem with getting arguments (check that you are using btoa() on client when using AT_base64 arg type in action.php)

=== Some player action is triggered randomly when I click somewhere on the game area ===

You probably used "dojo.connect" on a null object. In this case, dojo.connect associate the event (ex: "onclick") to the whole game area.

Most of the time it happens in this situation, when my_object element does not exists:
<pre>
dojo.connect( $("my_object"), "onclick", this, (event)=>{})
</pre>

To determine if this is the case, place "alert( $("my_object") )" before the dojo.connect to check if the object exists or not.

=== Error: This is not your turn ===

This happens when checkAction() is called and current player is NOT the active player.

You can change the active player in studio by clicking the red arrow next to their name in the player panel (right side of the page).

[[File:Change_active_player.jpg]]

=== Error: Please wait, an action is already in progress ===
Its followed by error "(Generated by checkAction / XXX)" on studio.

This error is triggered in the JS by the checkAction function for XXX action.

This can happen when the player sent an Ajax request action earlier, and:
* action is not complete yet - i.e. takes some time, and user clicked something again
* if there is bug in interface where MULTIPLE handlers are fired on same click. To debug this add some console.trace() in place this specific checkAction is called.
* did not get any notification from the PHP side. To avoid this, put an empty notifyPlayer in the PHP side of the Ajax handler to ensure the client receives a response. This line of code should do it:
<pre>
$this->notifyPlayer($this->getCurrentPlayerId(), 'message', '', []); // sent to current player, who originated the action
</pre>

=== Error: This move is not authorized now ===
This is generic error message generated by this.showMoveUnauthorized() function. If you did not call this function yourself, check the console log, it may have additional information.
If you see "Move not authorized now : XXX" in the log, where XXX is your action name - this means that action XXX is not defined in list of possible actions for your current state. This error generated by checkAction() function.

=== Error: You are not connected - after waiting for the submitted move ===
In the log you may find:
Query execution was interrupted, maximum statement execution time exceeded - Request: SELECT global_id, global_value FROM global WHERE 1

The error message above is because of failed attempt to lock a table, which happens because of infinite loop in you game.
* Check that don't enter same game state over and over again
* Check that you reverse for loop actually descrease counter or other loop issues
* Check that recursive function ends

== Predefined server errors ==

=== Unexpected error: Unexpected final game state (XX) ===

The action function does not transition to any state, i.e.
function selectField($field) {
self::checkAction ( 'selectField' );
if ($field!=0) $this->gamestate->nextState ( 'next' );
}
Here if $field is 0 there is no transition

=== This game action is impossible right now ===

Check the game log. Usually your state does not define the action you trying to perform in 'possibleactions' array.

Also check your onActionName javascript function. Make sure you are calling the right "actionname.html".

=== Unexpected error: This transition (playerTurn) is impossible at this state (42) ===

This is pretty self explanatory. Function nextState() takes transition name not a state name, so you probably did not
define this transition that the given state

== Game interface hangs during reload or on start ==

Showing "Application Loading..."

=== Javascript error: During pageload undefined no_stack_avail Script: ===

This error usually has no useful data, but it means you called somes API that require a callback and did not define callback function, i.e
in dojo.connect, this.connectClass, dojo.subscribe, etc

this.connectClass('field', 'onclick', 'onField'); // <-- onField is not defined

=== Other errors with "Application loading..." ===

You probably have a syntax error in your Javascript code, and the interface refuses to load.

To find this error, check if there is an error message in the Javascript console (F12).

If there is really nothing on the log, it's probably that the system was unable to load your Javascript because of an syntax error that affect the structure of the Javascript file, typically a missing "}" or a missing "," after a method definition.

If you have "Uncaught ReferenceError: bgagame is not defined" you have major syntax error in your js file, you should see some other clues in the log where the errors is.

If you have "dojo.publish is not defined" or something similar, this could be caused by another error earlier. For example, a syntax error caused by a malformed generated file (such as using newlines in tiebreaker description). Also you might have left some images in the /img directory with special characters in the name which must be removed. If you edited images for the game box and website, ensure that you have not left any unnecessary files there.

=== Unexpected Syntax Error: ===

No further details in the log. When log is filling with some social connect errors.

Possible Reason: Syntax error in of the php script which is loaded before the start, such as gameoptions.inc.php, gameinfos.inc.php and such.

=== Game interface spins in a loop throwing error ===

Errors is something like "Cannot read property 'is_ai' of undefined". Cannot restart the game because cannot access UI to stop.
Likely you get in actplayer state with player id == 0. The only way to fix it is to edit database, globals index == 2 set player id to one of your test dudes
(can copy from row 5 for example).

=== Unable to find table database (1): ebd_yourgame_112222 ===

Its either temporarily server error especially on studio it timeouts sometimes, just try reloading again.
Or check if you have syntax errors in your php game file or sql.

== Type conversion / juggling errors ==

=== On php side I get a number instead of string I expect ===

$num = 3;
$meeple = "meeple_" + $num; // <-- suppose to be "meeple_3"!

When you switch between JS and PHP it easy to type this and not notice the +. Plus sign (+) in php does not mean string concatenation (in javascript does!),
in php + means integer arithmetic. So change + to . (dot)

=== On php side my string comparison does not work ===

if ($color == '4baae2' || $color == '000000') {
}

Apparently you should not be using '==' in php to compare strings! You should use '==='. The (==) operator will typecast the strings
to numbers then do comparison!
Its not very apparent because usually you can get away with it, but not when strings resemble numbers like hex 'colors'.

=== Integer columns in the database are returned as strings ===

This is normal PHP behavior. All fields are returned as string type, regardless of their actual type in the database. This also applies to global variables accessed via getGameStateValue(), since they are stored in a database table.

You can use type-casting to convert them to the correct type after they come out of the database.

$myValueInt = (int)self::getGameStateValue(GLOBAL_ROUND_NUMBER);

or

$myValueInt = self::getGameStateValue(GLOBAL_ROUND_NUMBER) + 0; // adding 0 casts to int

same with direct qdb ueries
$sql = "SELECT my_int_column FROM my_table WHERE my_condition";
$myResult = self::getUniqueValueFromDB($sql); <-- this is a string
$myResultAsInt = (int)$myResult;

https://stackoverflow.com/questions/5323146/mysql-integer-field-is-returned-as-string-in-php

== Zombie mode ==

=== Unexpected error: Propagating error from GS 1 (method: zombie): Not logged ===

You are probably calling getCurrentPlayerId() or getCurrentPlayerName() in your zombieTurn method or any of the methods it uses. Instead, use the $active_player_id provided as parameter to zombieTurn().

If you do not see these commands within "function zombieTurn( $state, $active_player ){}", check all the functions called from zombieTurn, also "function getGameProgression(){}" and all the functions THAT calls.

=== Unexpected error: Can't manage zombie player in this game state ===

The state the game was in at the time the error was generated didn't have "transitions" => array( "zombiePass" => 27 )" in states.inc.php (27 was an arbitrary example, but everything else must be spelled exactly that way.)

To correct this error, either add "zombiePass" => ## to the transitions array or work out why the game is in a state it should not be in.

=== Unexpected error: Wrong formatted data from BGA gameserver 1 (method: zombie): ===

This is almost certainly an undefined value in PHP code. Look for a warning or error message in the game replay log on the right side of the table UI.

=== Unexpected error: BGA gameserver 1 do not respond (method: zombie) (timeout: cluster) ===

You are trying to end the game from a zombie method. This is not allowed. The zombie logic must continue the game as best it can. See [[Main_game_logic:_yourgamename.game.php#Zombie_mode|Zombie mode]] for more info.

=== Game unexpectedly ends when one player becomes zombie ===

There is an error in handling zombie mode, check error log. Example: if the zombie turn is called again, framework detects a infinite loop and cancels the game. On the studio there is a notification called ZombieTurnFailed

== Other errors ==

=== Javascript does not know how to sum two numbers ===

Be careful when you manipulate integers returned by notifications: most of the time, Javascript considers they are Strings and not Integers.

As a result:
<pre>
var i=1;
i += notif.args.increment; // With notif.args.increment='1'
alert( i ); // i=11 instead of 2 !! Javascript concatenate 2 strings !
</pre>

To solve this, you should use the "toint" function:
<pre>
var i=1;
i += toint( notif.args.increment ); // With notif.args.increment='1'
alert( i ); // i=2 :)
</pre>

=== Javascript: do not use substr with negative numbers ===

To get the last characters of a string, use "slice" instead of "substr" which has a bug on IE:
<pre>
var three_last_characters = string.substr( -3 ); // Wrong
var three_last_characters = string.slice( -3 ); // Correct
</pre>

=== Game "spontaneously" transition to a new state without user input ===

Make sure on php side you have no code after $this->gamestate->nextState(...) code.
Because if you do accidentally have code that goes to another state it will cause another state transition without user interaction.

function selectField($field) {
self::checkAction ( 'selectField' );
if ($field!=0) $this->gamestate->nextState ( 'next' );
$this->gamestate->nextState ( 'last' ); // <-- here is missing else, so it will cause double state transition
}

=== Message "Invalid or missing substitution argument for log message: ${actplayer} ... " when entering a state ===

You probably have an args function defined for that state that does '''not''' return an array

=== Server syntax error: Warning: count(): Parameter must be an array or an object that implements Countable in /var/tournoi/release/tournoi-220308-1000-gs/www/game/module/table/gamestate.game.php on line 823 ===

Generally comes with that syntax error : Warning: implode(): Invalid arguments passed in /var/tournoi/release/tournoi-220308-1000-gs/www/game/module/table/gamestate.game.php on line 845

It is most probable that you used setPlayersMultiactive method with id of a single player not included in an array -> you should use : ... setPlayersMultiactive( array($player_id), ...

[[Category:Studio]]

Tutorial reversi

2022-06-08T16:47:11Z

VKV FR: Adding new required charset setting in table creation request.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] );" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-07T20:52:05Z

VKV FR: Added missing semi-colon.

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] );" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-07T19:10:25Z

VKV FR: /* Let it look like Reversi */

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory. Warning: use lowercase file names!
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

'''Important: refresh your page.''' Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, refresh the page (always do this when you update the CSS file), and check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] )" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-07T19:00:23Z

VKV FR: /* Create your first game */

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== (Optional) Editing the game information ==

This step is optional and will fix the warnings on the project page (missing BGG_ID and presentation).
* Edit your local copy of the gameinfo.inc.php file:
** Change the 'bgg_id' value from 0 to 2389 - that's around line 37.
** Add "1," to the players array - that's around line 41.
** Change the presentation array content - that's around line 134. Uncomment one line and change the text. Remove the final comma if you keep only one line!
* Upload the gameinfo.inc.php file to the SFTP server (see [[First_steps_with_BGA_Studio#Connect_to_your_SFTP_folder|Connect to your SFTP folder]]).
* Go back to your project page, and in the "Game Information" section, click "Reload game information".
* Finally, refresh the project page in your browser (usually CTRL-F5).

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory.
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

Refresh your page. Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] )" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-07T18:44:02Z

VKV FR: /* Create your first game */

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project. ''Note: there are warnings displayed about a missing BGG_ID and presentation text. You can ignore that for now.''
* Click the Play link next to your project name. This will open the Play page and offer to create a new table for your project. ''Optional: click the Heart icon to add your project to your favorite games list.''
* On the Play page, on the top of the page, make sure that your settings are "Simple game", "Real time" and "Manual".
* Click "Create table" to create a table of your project.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

End the game by clicking on the game options icon on the top right, and then on "Express Stop".

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory.
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

Refresh your page. Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] )" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-07T18:32:12Z

VKV FR: /* Create your first game */

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided in your project, you can already start a game from the BGA Studio:
* Go to your studio Control panel, then Manage games and select your initial project.
* Click the Play link next to your project name.
* For now, we are going to work with one player only, so use the (-) button to set the number of players to 1. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games. If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)
* Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory.
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

Refresh your page. Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] )" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

Tutorial reversi

2022-06-07T17:23:25Z

VKV FR: /* Create your first game */

{{Studio_Framework_Navigation}}

== Introduction ==

Using this tutorial, you can build a complete working game on the BGA environment: Reversi.

Before you read this tutorial, you must:
* Read the overall presentations of the BGA Framework ([[Studio|see here]]).
* Know the [http://en.wikipedia.org/wiki/Reversi#Rules rules of Reversi].
* Know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
* Setup your development environment [http://en.doc.boardgamearena.com/First_steps_with_BGA_Studio First Steps with BGA Studio]

== Create your first game ==

''Note: you should already have created a project following instructions in [[First_steps_with_BGA_Studio#Create_a_new_game_project|Create a new game project]]. While you will find a '''reversi''' directory in your SFTP folder, do not use it for this tutorial. Instead, use the project you have created as an (empty) starting point.''

With the initial skeleton of code provided initially, you can already start a game from the BGA Studio. Go to your studio control panel, then Manage games and select your initial project. Finally, click the Play link. For now, we are going to work with one player only. Most of the time it is simpler to proceed with only one player during the early phase of development of your game, as it's easy and fast to start/stop games.

(If you choose to start with 2 players, you should see two names on the right: testdude0 and testdude1. To switch between them, press the red arrow button near their names; it will open another tab. This way you don't need to login and logout from multiple accounts.)

Reminder: Always use the "Express Start" button to start the game.

Thus, you can start a "Reversi" game, and arrive on a void, empty game. Yeah.

== Let it look like Reversi ==

It's always a good idea to start with a little bit of graphic work. Why? Because this helps to figure out how the final game will be, and issues that may appear later.

Be careful designing the layout of your game: you must always keep in mind that players with a 1024px screen width must be able to play. Usually, it means that the width of the play area can be 750px (in the worst case).

For Reversi, it's useless to have a 750x750px board - much too big, so we choose this one which fit perfectly (536x528):

[[File:Board.jpg]]

Note that we are using a jpg file. Jpg are lighter than png, so faster to load. Later we are going to use PNGs for discs for transparency purpose.

Now, let's make it appear in our game:
* upload board.jpg in your "img/" directory.
* edit "reversi_reversi.tpl" to add a 'div' for your board.

Note: If you are building this game by following the tutorial, you will have a different project name than 'reversi'. The file names in your project will be different than shown in this tutorial, replacing 'reversi' with your project name. It should be trivial to find the right file in your project, but be sure that any code (other than comments) that references 'reversi' is changed to your actual project name.

<pre>
<div id="board">
</div>
</pre>

* edit your reversi.css file to transform it into a visible board:

#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
}

Refresh your page. Here's your board:

[[File:reversi1.jpg]]

If the board does not appear, check the image filename. Remember file names are case sensitive!

== Make the squares appear ==

Now, we need to create some invisible HTML elements where squares are. These elements will be used as position references for white and black discs.
We need 64 squares. To avoid writing 64 'div' elements on our template, we are going to use the "block" feature.

Let's modify our template like this:

<pre>
<div id="board">

<div id="square_{X}_{Y}" class="square" style="left: {LEFT}px; top: {TOP}px;"></div>

</div>
</pre>

As you can see, we created a "square" block, with 4 variable elements: X, Y, LEFT and TOP. We are going to use this block 64 times during page load.

Let's do it in our "reversi.view.php" file, inside the build_page function:

<pre>
$this->page->begin_block( "reversi_reversi", "square" );

$hor_scale = 64.8;
$ver_scale = 64.4;
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$this->page->insert_block( "square", array(
'X' => $x,
'Y' => $y,
'LEFT' => round( ($x-1)*$hor_scale+10 ),
'TOP' => round( ($y-1)*$ver_scale+7 )
) );
}
}
</pre>

Note: as you can see, squares in our "board.jpg" files do not have an exact width/height in pixels, and that's the reason we are using floating point numbers here.

Now, to finish our work and check if everything works fine, we are going to style our square a little bit in our CSS stylesheet:

<pre>
#board {
width: 536px;
height: 528px;
background-image: url('img/board.jpg');
position: relative;
}

.square {
width: 62px;
height: 62px;
position: absolute;
background-color: red;
}
</pre>

Explanations:
* With "position: relative" on board, we ensure square elements are positioned relatively to board.
* For the test, we use a red background color for the square. This is a useful tip to figure out if everything is fine with invisible elements.

Let's refresh and check our our (beautiful) squares:

[[File:reversi2.jpg]]

If the red squares do not appear, check your css file (Chrome DevTools: Application > Frames > top > Stylesheets > reversi.css). If your changes are not there try clearing your cache!

Hint: Now that we know our squares are set up correctly, we can hide the red background. You can remove the "background-color: red;" line from your .square class in the CSS stylesheet.

== The discs ==

Now, our board is ready to receive some disc tokens!

[Note: Throughout this tutorial, sometimes "tokens" is used, and sometimes "discs" is used. They are often swapped if you're looking at code in the reversi example project.]

At first, we introduce a new 'div' element as a child of "board" to host all these tokens (in our template):

<pre>


<div id="tokens">
</div>
</div>
</pre>

Then, let's introduce a new piece of art with the discs. We need some transparency here so we are using a png file:

[[File:tokens.png]]

Upload this image file "tokens.png" in your "img/" directory.

Important: we are using ONE file for both discs. It's really important that you use a minimum number of graphic files for your game with this "CSS sprite" technique, because it makes the game loading faster and more reliable. [http://www.w3schools.com/css/css_image_sprites.asp Read more about CSS sprites].

Now, let's separate the disc with some CSS stuff:

<pre>
.token {
width: 56px;
height: 56px;
position: absolute;
background-image: url('img/tokens.png');
}
.tokencolor_ffffff { background-position: 0px 0px; }
.tokencolor_000000 { background-position: -56px 0px; }
</pre>

With this CSS code, we apply the classes "token" and "tokencolor_ffffff" to a div element and we've got a white token. Yeah.

Note the "position: absolute" which allows us to position tokens on the board and make them "slide" to their positions.

Now, let's make a first token appear on our board. Disc tokens are not visible at the beginning of the game: they appear dynamically during the game. For this reason, we are going to make them appear from our Javascript code, with a BGA Framework technique called "JS template".

In our template file (reversi_reversi.tpl), let's create the piece of HTML needed to display our token:

<pre>
<script type="text/javascript">

// Templates

var jstpl_token='<div class="token tokencolor_${color}" id="token_${x_y}"></div>';

</script>
</pre>

Note: we already created the "templates" section for you in the game skeleton.

As you can see, we defined a JS template named "jstpl_token" with a piece of HTML and two variables: the color of the token and its x/y coordinates. Note that the syntax of the argument is different for template block variables (braces <code>{}</code>) and JS template variables (dollar and braces <code>${}</code>).

Now, let's create a method in our Javascript code (in the "reversi.js" file) that will make a token appear on the board, using this template. Add under the section //// Utility methods:

<pre>
addTokenOnBoard: function( x, y, player )
{
dojo.place( this.format_block( 'jstpl_token', {
x_y: x+'_'+y,
color: this.gamedatas.players[ player ].color
} ) , 'tokens' );

this.placeOnObject( 'token_'+x+'_'+y, 'overall_player_board_'+player );
this.slideToObject( 'token_'+x+'_'+y, 'square_'+x+'_'+y ).play();
},
</pre>

At first, with "dojo.place" and "this.format_block" methods, we create a HTML piece of code and insert it as a new child of "tokens" div element.

Then, with BGA "this.placeOnObject" method, we place this element over the panel of some player. Immediately after, using BGA "this.slideToObject" method, we make the disc slide to the "square" element, its final destination.

"'overall_player_board_'+player" refers to the div element that contains each player's information and avatar. By initially placing the token here, it gives the effect that the player's avatar is throwing the token onto the board.

Note: don't forget to call the "play()", otherwise the token remains at its original location.

Note: note that during all the process, the parent of the new disc HTML element will remain "tokens". placeOnObject and slideToObject methods are only moving the position of elements on screen, and they are not modifying the HTML tree.

Before we can show a token, we need to set the player colors in the setupNewGame function in reversi.game.php:
<pre>
$default_colors = array( "ffffff", "000000" );
</pre>

Note: Probably you'll have to remove the line "self::reattributeColorsBasedOnPreferences( $players, $gameinfos['player_colors'] );".

Now, to test if everything works fine, just add "this.addTokenOnBoard( 2, 2, [player_id] )" in the "setup" Javascript method in reversi.js, and restart the game.

A token should appear and slide immediately to its position, like this:

[[File:reversi3.jpg]]

== The database ==

We did most of the client-side programming, so let's have a look on the other side now.

To design the database model of our game, the best thing to do is to follow the "Go to game database" link at the bottom of our game, to access the database directly with a [http://www.phpmyadmin.net/ PhpMyAdmin] instance. Your PhpMyAdmin username/password is in your welcome email (and currently the same as the SFTP username/password).

Then, you can create the tables you need for your game (do not remove existing tables!), and report every SQL command used in your "dbmodel.sql" file. How do you generate SQL to create table after creating the table in the UI? See [https://www.itsupportguides.com/knowledge-base/tech-tips-tricks/how-to-generate-sql-create-table-script-using-phpmyadmin/ here]. Add 'IF NOT EXISTS' to the CREATE TABLE sql (see example below).

[[File:reversi4.jpg]]

The database model of Reversi is very simple: just one table with the squares of the board.

<pre>
CREATE TABLE IF NOT EXISTS `board` (
`board_x` smallint(5) unsigned NOT NULL,
`board_y` smallint(5) unsigned NOT NULL,
`board_player` int(10) unsigned DEFAULT NULL,
PRIMARY KEY (`board_x`,`board_y`)
) ENGINE=InnoDB;
</pre>

Add the above SQL to dbmodel.sql. Now, a new database with a "board" table will be created each time we start a Reversi game. This is why after modifying our dbmodel.sql it's a good time to stop & start again our game.

== Setup the initial game position ==

The "setupNewGame" method of our reversi.game.php is called during initial setup: this is the place to initialize our data and to place the initial tokens on the board (initially, there are 4 tokens on the board).

Let's do this:

<pre>
// Init the board
$sql = "INSERT INTO board (board_x,board_y,board_player) VALUES ";
$sql_values = array();
list( $blackplayer_id, $whiteplayer_id ) = array_keys( $players );
for( $x=1; $x<=8; $x++ )
{
for( $y=1; $y<=8; $y++ )
{
$token_value = "NULL";
if( ($x==4 && $y==4) || ($x==5 && $y==5) ) // Initial positions of white player
$token_value = "'$whiteplayer_id'";
else if( ($x==4 && $y==5) || ($x==5 && $y==4) ) // Initial positions of black player
$token_value = "'$blackplayer_id'";

$sql_values[] = "('$x','$y',$token_value)";
}
}
$sql .= implode( ',', $sql_values );
self::DbQuery( $sql );

// Active first player
self::activeNextPlayer();
</pre>

We create one table entry for each square, with a "NULL" value which means "empty square". For 4 specific squares, we place an initial token.

At the end, we call activeNextPlayer to make the first player active at the beginning of the game.

You need to remove the call to self::reattributeColorsBasedOnPreferences() in SetupNewGame() so that any player color preferences do not override the two colors supported here.

Now, we need to make these tokens appear on the client side. The first step is to return the token positions with our "getAllDatas" PHP method (called during each page reload):

<pre>
// Get reversi board token
$result['board'] = self::getObjectListFromDB( "SELECT board_x x, board_y y, board_player player
FROM board
WHERE board_player IS NOT NULL" );
</pre>

We are using the BGA framework "getObjectListFromDB" method that formats the result of this SQL query in a PHP array with x, y and player attributes.

Last, we process this array client side, and place a disc token on the board for each array item. We do this using our Javascript "setup" method:

<pre>
for( var i in gamedatas.board )
{
var square = gamedatas.board[i];

if( square.player !== null )
{
this.addTokenOnBoard( square.x, square.y, square.player );
}
}
</pre>

Our "board" entry created in "getAllDatas" can be used here as "gamedatas.board" in our Javascript. We are using our previously developed "addTokenOnBoard" method.

Reload... and here we are:

[[File:reversi5.jpg]]

It starts to smell Reversi here...

== The game state machine ==

Now, let's stop our game again, because we are going to start the core game logic.

You already read [http://www.slideshare.net/boardgamearena/bga-studio-focus-on-bga-game-state-machine Focus on BGA game state machine], so you know that this is the heart of your game logic. For reversi, it's very simple. Here's a diagram of our game state machine:

[[File:reversi6.jpg]]

And here's our "states.inc.php", according to this diagram:

<pre>
$machinestates = array(

1 => array(
"name" => "gameSetup",
"description" => clienttranslate("Game setup"),
"type" => "manager",
"action" => "stGameSetup",
"transitions" => array( "" => 10 )
),

10 => array(
"name" => "playerTurn",
"description" => clienttranslate('${actplayer} must play a disc'),
"descriptionmyturn" => clienttranslate('${you} must play a disc'),
"type" => "activeplayer",
"args" => "argPlayerTurn",
"possibleactions" => array( 'playDisc' ),
"transitions" => array( "playDisc" => 11, "zombiePass" => 11 )
),

11 => array(
"name" => "nextPlayer",
"type" => "game",
"action" => "stNextPlayer",
"updateGameProgression" => true,
"transitions" => array( "nextTurn" => 10, "cantPlay" => 11, "endGame" => 99 )
),

99 => array(
"name" => "gameEnd",
"description" => clienttranslate("End of game"),
"type" => "manager",
"action" => "stGameEnd",
"args" => "argGameEnd"
)

);
</pre>

Now, let's create in reversi.game.php the methods that are declared in this game states description file:
* argPlayerTurn
* stNextPlayer

... and start a new Reversi game.

As you can see on the screen capture below, the BGA framework makes the game jump to our first game state "playerTurn" right after the initial setup. That's why the status bar contains the description of playerTurn state ("XXXX must play a disc"):

[[File:reversi7.jpg]]

== The rules ==

We will use the "getPossibleMoves" PHP method to:
* Indicate to the current player where she is allowed to play by returning a list of coordinates
* Check if the player has the right to play in the spot they choose

<blockquote>
Example of getPossibleMoves here https://gist.github.com/leocaseiro/a8bc2851bd0caddd06685b5035937d15
</blockquote>

This is pure PHP programming here, and there are no special things from the BGA framework that can be used. This is why we won't go into details here. The overall idea is:
* Create a "getTurnedOverDiscs(x,y)" method that returns coordinates of discs that would be turned over if a token would be played at x,y.
* Loop through all free squares of the board and call the "getTurnedOverDiscs" method on each of them. If at least 1 token is turned over, this is a valid move.

IMPORTANT: Keep in mind that making a database query is slow, so please don't load the entire game board with a SQL query multiple times. In our implementation, we load the entire board once at the beginning of "getPossibleMoves", and then pass the board as an argument to all methods.

If you want to look into details, please look at the "utility method" sections of reversi.game.php. If building the tutorial yourself, copy the functions under "Utility functions" comment from the Reversi tutorial.

== Display allowed moves ==

Now we want to highlight the squares where the player can place a disc.

To do this, we add a "argPlayerTurn" method in reversi.game.php. This method is called on the server each time we enter into "playerTurn" game state, and its result is transferred automatically to the client-side:

<pre>
function argPlayerTurn()
{
return array(
'possibleMoves' => self::getPossibleMoves( self::getActivePlayerId() )
);
}
</pre>

We use the "getPossibleMoves" method we just developed.

Each time we enter into a new game state, we use the "onEnteringState" Javascript method (in the reversi.js file, under "Game & client states"). This lets us use the data returned by the method above on the client side.

<pre>
onEnteringState: function( stateName, args )
{
console.log( 'Entering state: '+stateName );

switch( stateName )
{
case 'playerTurn':
this.updatePossibleMoves( args.args.possibleMoves );
break;
}
},
</pre>

So, when we enter into "playerTurn" game state, we call our "updatePossibleMoves" method (under the "Utility functions" section). This method looks like this:

<pre>
updatePossibleMoves: function( possibleMoves )
{
// Remove current possible moves
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

for( var x in possibleMoves )
{
for( var y in possibleMoves[ x ] )
{
// x,y is a possible move
dojo.addClass( 'square_'+x+'_'+y, 'possibleMove' );
}
}

this.addTooltipToClass( 'possibleMove', '', _('Place a disc here') );
},
</pre>
Here's what this does. At first, it removes all "possibleMove" classes currently applied with the very useful combination of "dojo.query" and "removeClass" method.

Then it loops through all possible moves our PHP "updatePossibleMoves" function created for us, and adds the "possibleMove" class to each corresponding square.

Finally, it uses the BGA framework "addTooltipToClass" method to associate a tooltip to all those highlighted squares so that players can understand their meaning.

To see the possible moves we need to create a CSS class ("possibleMove") that can be applied to a "square" element to highlight it:
<pre>
.possibleMove {
background-color: white;
opacity: 0.2;
filter:alpha(opacity=20); /* For IE8 and earlier */
cursor: pointer;
}
</pre>

And here we are:

[[File:reversi8.jpg.jpg]]

== Let's play ==

From now, it's better to restart a game with 2 players, because we are going to implement a complete Reversi turn. The summary of what we are going to do is:
* When we click on a "possibleMove" square, send the move to the server.
* Server side, check the move is correct, apply Reversi rules and jump to next player.
* Client side, change the disc position to reflect the move.

First we associate each click on a square to one of our methods using our Javascript "setup" method:

<pre>
dojo.query( '.square' ).connect( 'onclick', this, 'onPlayDisc' );
</pre>

Note the use of the "dojo.query" method to get all HTML elements with "square" class in just one function call. Now, our "onPlayDisc" method is called each time someone clicks on a square.

Here's our "onPlayDisc" method below:

<pre>
onPlayDisc: function( evt )
{
// Stop this event propagation
dojo.stopEvent( evt );

// Get the clicked square x and y
// Note: square id format is "square_X_Y"
var coords = evt.currentTarget.id.split('_');
var x = coords[1];
var y = coords[2];

if( ! dojo.hasClass( 'square_'+x+'_'+y, 'possibleMove' ) )
{
// This is not a possible move => the click does nothing
return ;
}

if( this.checkAction( 'playDisc' ) ) // Check that this action is possible at this moment
{
this.ajaxcall( "/reversi/reversi/playDisc.html", {
x:x,
y:y
}, this, function( result ) {} );
}
},
</pre>

What we do here is:
* We stop the propagation of the Javascript "onclick" event. Otherwise, it can lead to random behavior so it's always a good idea.
* We get the x/y coordinates of the square by using "evt.currentTarget.id".
* We check that clicked square has the "possibleMove" class, otherwise we know for sure that we can't play there.
* We check that "playDisc" action is possible, according to current game state (see "possibleactions" entry in our "playerTurn" game state defined above). This check is important to avoid issues if a player double clicks on a square.
* Finally, we make a call to the server using BGA "ajaxcall" method with argument x and y. Be sure to update the first parameter to match your game if building the tutorial yourself. E.g. "/yourgamename/yourgamename/playDisc.html"

Now, we have to manage this "playDisc" action on the server side. At first, we introduce a "playDisc" entry point in our "reversi.action.php":

<pre>
public function playDisc()
{
self::setAjaxMode();
$x = self::getArg( "x", AT_posint, true );
$y = self::getArg( "y", AT_posint, true );
$result = $this->game->playDisc( $x, $y );
self::ajaxResponse( );
}
</pre>

As you can see, we get the 2 arguments x and y from the javascript call, and call a corresponding "playDisc" method in our game logic (reversi.game.php).

Now, let's have a look of this playDisc method:

<pre>
function playDisc( $x, $y )
{
// Check that this player is active and that this action is possible at this moment
self::checkAction( 'playDisc' );
</pre>

... at first, we check that this action is possible according to current game state (see "possible action"). We already did it on client side, but it's important to do it on server side too (otherwise it would be possible to cheat).

<pre>
// Now, check if this is a possible move
$board = self::getBoard();
$player_id = self::getActivePlayerId();
$turnedOverDiscs = self::getTurnedOverDiscs( $x, $y, $player_id, $board );

if( count( $turnedOverDiscs ) > 0 )
{
// This move is possible!
</pre>

...now, we are using the "getTurnedOverDiscs" method again to check that this move is possible.

<pre>
// Let's place a disc at x,y and return all "$returned" discs to the active player

$sql = "UPDATE board SET board_player='$player_id'
WHERE ( board_x, board_y) IN ( ";

foreach( $turnedOverDiscs as $turnedOver )
{
$sql .= "('".$turnedOver['x']."','".$turnedOver['y']."'),";
}
$sql .= "('$x','$y') ) ";

self::DbQuery( $sql );

</pre>

... we update the database to change the color of all turned over disc + the disc we just placed.

<pre>
// Update scores according to the number of disc on board
$sql = "UPDATE player
SET player_score = (
SELECT COUNT( board_x ) FROM board WHERE board_player=player_id
)";
self::DbQuery( $sql );

// Statistics
self::incStat( count( $turnedOverDiscs ), "turnedOver", $player_id );
if( ($x==1 && $y==1) || ($x==8 && $y==1) || ($x==1 && $y==8) || ($x==8 && $y==8) )
self::incStat( 1, 'discPlayedOnCorner', $player_id );
else if( $x==1 || $x==8 || $y==1 || $y==8 )
self::incStat( 1, 'discPlayedOnBorder', $player_id );
else if( $x>=3 && $x<=6 && $y>=3 && $y<=6 )
self::incStat( 1, 'discPlayedOnCenter', $player_id );

</pre>

... now, we update both player score by counting all disc, and we manage game statistics.

<pre>
// Notify
self::notifyAllPlayers( "playDisc", clienttranslate( '${player_name} plays a disc and turns over ${returned_nbr} disc(s)' ), array(
'player_id' => $player_id,
'player_name' => self::getActivePlayerName(),
'returned_nbr' => count( $turnedOverDiscs ),
'x' => $x,
'y' => $y
) );

self::notifyAllPlayers( "turnOverDiscs", '', array(
'player_id' => $player_id,
'turnedOver' => $turnedOverDiscs
) );

$newScores = self::getCollectionFromDb( "SELECT player_id, player_score FROM player", true );
self::notifyAllPlayers( "newScores", "", array(
"scores" => $newScores
) );
</pre>

... then we notify about all these changes. We are using for that 3 notifications ('playDisc', 'turnOverDiscs' and 'newScores' that we are going to implement on client side later). Note that the description of the 'playDisc' notification will be logged in the game log.

<pre>
// Then, go to the next state
$this->gamestate->nextState( 'playDisc' );
}
else
throw new BgaSystemException( "Impossible move" );
}
</pre>

... finally, we jump to the next game state if everything goes fine ('playDisc' is the name of a transition in the 'playerTurn' game state description above which leads to state 11 which is 'nextPlayer').

To make the statistics work, we have to initialize them in stats.inc.php:

<pre>
// Statistics existing for each player
"player" => array(

"discPlayedOnCorner" => array( "id"=> 10,
"name" => totranslate("Discs played on a corner"),
"type" => "int" ),

"discPlayedOnBorder" => array( "id"=> 11,
"name" => totranslate("Discs played on a border"),
"type" => "int" ),

"discPlayedOnCenter" => array( "id"=> 12,
"name" => totranslate("Discs played on board center part"),
"type" => "int" ),

"turnedOver" => array( "id"=> 13,
"name" => totranslate("Number of discs turned over"),
"type" => "int" )
)
</pre>

A last thing to do on the server side is to activate the next player when we enter the "nextPlayer" game state (in the "reversi.game.php" file, under "Game state reactions"):

<pre>
function stNextPlayer()
{
// Active next player
$player_id = self::activeNextPlayer();

// Check if both player has at least 1 discs, and if there are free squares to play
$player_to_discs = self::getCollectionFromDb( "SELECT board_player, COUNT( board_x )
FROM board
GROUP BY board_player", true );

if( ! isset( $player_to_discs[ null ] ) )
{
// Index 0 has not been set => there's no more free place on the board !
// => end of the game
$this->gamestate->nextState( 'endGame' );
return ;
}
else if( ! isset( $player_to_discs[ $player_id ] ) )
{
// Active player has no more disc on the board => he looses immediately
$this->gamestate->nextState( 'endGame' );
return ;
}

// Can this player play?

$possibleMoves = self::getPossibleMoves( $player_id );
if( count( $possibleMoves ) == 0 )
{

// This player can't play
// Can his opponent play ?
$opponent_id = self::getUniqueValueFromDb( "SELECT player_id FROM player WHERE player_id!='$player_id' " );
if( count( self::getPossibleMoves( $opponent_id ) ) == 0 )
{
// Nobody can move => end of the game
$this->gamestate->nextState( 'endGame' );
}
else
{
// => pass his turn
$this->gamestate->nextState( 'cantPlay' );
}
}
else
{
// This player can play. Give him some extra time
self::giveExtraTime( $player_id );
$this->gamestate->nextState( 'nextTurn' );
}

}
</pre>

Now, when we play a disc, the rules are checked and the disc appears in the database.

[[File:reversi9.jpg]]

Of course, as we don't manage notifications on client side, we need to press F5 after each move to see the changes on the board.

== Make the move appear automatically ==

Now, what we have to do is process the notifications sent by the server and make the move appear on the interface.

In our "setupNotifications" method, we register 2 methods for the 2 notifications we created at the previous step ('playDisc' and 'turnOverDiscs'):

<pre>
dojo.subscribe( 'playDisc', this, "notif_playDisc" );
this.notifqueue.setSynchronous( 'playDisc', 500 );
dojo.subscribe( 'turnOverDiscs', this, "notif_turnOverDiscs" );
this.notifqueue.setSynchronous( 'turnOverDiscs', 1500 );
dojo.subscribe( 'newScores', this, "notif_newScores" );
this.notifqueue.setSynchronous( 'newScores', 500 );
</pre>

As you can see, we associate each of our 3 notifications with a method prefixed with "notif_". We also define these notifications as "synchronous", with a duration in millisecond. It tells the user interface to wait some time after executing the notification, to let the animation end before starting the next notification. In our specific case, the animation will be the following:
* Make a disc slide from the player panel to its place on the board
* (wait 500ms)
* Make all turned over discs blink (and of course turned them over)
* (wait 1500ms)
* Update the player scores
* (wait 500ms)

The 2nd parameter in dojo.subscribe call (this) is the 'context', and will be passed in as a parameter to the specified method.

Let's have a look now on the "playDisc" notification handler method:

<pre>
notif_playDisc: function( notif )
{
// Remove current possible moves (makes the board more clear)
dojo.query( '.possibleMove' ).removeClass( 'possibleMove' );

this.addTokenOnBoard( notif.args.x, notif.args.y, notif.args.player_id );
},
</pre>

No surprise here, we re-used some existing stuff to:
* Remove the highlighted squares.
* Add a new disc on board, coming from player panel.

Now, here's the method that handles the turnOverDiscs notification:

<pre>
notif_turnOverDiscs: function( notif )
{
// Get the color of the player who is returning the discs
var targetColor = this.gamedatas.players[ notif.args.player_id ].color;

// Make these discs blink and set them to the specified color
for( var i in notif.args.turnedOver )
{
var token = notif.args.turnedOver[ i ];

// Make the token blink 2 times
var anim = dojo.fx.chain( [
dojo.fadeOut( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } ),
dojo.fadeOut( {
node: 'token_'+token.x+'_'+token.y,
onEnd: function( node ) {

// Remove any color class
dojo.removeClass( node, [ 'tokencolor_000000', 'tokencolor_ffffff' ] );
// ... and add the good one
dojo.addClass( node, 'tokencolor_'+targetColor );

}
} ),
dojo.fadeIn( { node: 'token_'+token.x+'_'+token.y } )

] ); // end of dojo.fx.chain

// ... and launch the animation
anim.play();
}
},
</pre>

The list of the discs to be turned over has been made available by our server side code in "notif.args.turnedOver" (see previous paragraph). We loop through all these discs, and create a complex animation using dojo.Animation for each of them. The complete documentation on dojo animations [http://dojotoolkit.org/documentation/tutorials/1.6/animation/ can be found here].

In few words: we create a chain of 4 animations to make the disc fade out, fade in, fade out again, and fade in again. At the end of the second fade out, we change the color of the disc. Finally, we launch the animation with "play()".

And Also the notification to update the scores:

<pre>
notif_newScores: function( notif )
{
for( var player_id in notif.args.scores )
{
var newScore = notif.args.scores[ player_id ];
this.scoreCtrl[ player_id ].toValue( newScore );
}
},
</pre>

[[Category:Studio]]

First steps with BGA Studio

2022-05-29T16:12:40Z

VKV FR:

{{Studio_Framework_Navigation}}

== Connect to the BGA Studio website ==

Go to BGA Studio website:
http://studio.boardgamearena.com

Choose one of your 10 accounts (ex: myusername0, password was sent in welcome email), and login into the website - as you would do for Board Game Arena.

If you don't have account see [[How to join BGA developer team?]]

== Create a new game project ==

You can do most of the projects-related operations from "Control Panel / Manage games". In particular, you can create a new project automatically from there.

Your first "game" should be one of the tutorials, so your project name should be something like "tutorialbob".

At this stage it is too early to create a real game but if you really don't want to start until you have a game in mind, check [[Create a game in BGA Studio: Complete Walkthrough]]
section "Select a First Game"

For reference top bar studio links
* AVAILABLE LICENSES - list of all available licenses (not public domain) - https://studio.boardgamearena.com/licensing
* STUDIO PROJECTS - list of all registered studio projects - https://studio.boardgamearena.com/projects
* CONTROL PANEL - manage projects - https://studio.boardgamearena.com/controlpanel. <br>Note: the control panel is accessible from the player popup menu (top right), with the gear and bargraph blue icon next to the player icon.

== Connect to your SFTP folder ==

From the initial email from the Studio you get:
* the name of the SFTP server to connect to
* your SFTP login and password

Using this information:
# Connect to the SFTP server using your SFTP login and password, through your favourite SFTP client software (such as [http://winscp.net/ WinSCP], see [[Tools_and_tips_of_BGA_Studio#File_Sync_on_Windows|File Sync]])
# Check that your remote home folder contains one folder for two example games (reversi, hearts). If you have already created a new game project, one additional folder should be in your "home" folder.
# Note: You have to setup AUTOMATED sync between your folder and remote folder, manually ftp'ing files would be no-starter. For WinSCP you can do this from the file menu (Commands->Keep remote directories up to Date...)

== Let's code! ==

Now, you can try to launch a new game on BGA Studio from the "Play now" menu entry, as you would do on Board Game Arena website.

# To launch your game from Studio go to Studio -> Control Panel -> Manage games -> <your_game> -> <your_game_page> -> Play now
# Use the 'I want between X and X' players to tick down the maximum players number to the minimum
# Click 'Express start': your game launches with the maximum number of players specified. It shows an empty canvas: in the game zone you just have a sentence 'This is your game interface. You can edit this HTML in your ".tpl" file.'. If you don't see Express start button make sure you are in Manual mode for game creation.
# Switch to your SFTP home folder, go into your game folder. Edit the game_game.tpl file, and change this sentence to 'Hey, this is my first game!', then save.
# Go back to your browser and refresh, check that the game zone has updated.
# Click the red arrow next to a test account's name in the player panel to view the game from that player's account <br/>[[File:Change_active_player.jpg]]
# From the Player page or Table page click on the link "You are playing <name of game> (realtime)" (or click on the 'Gear' icon on the top right) and choose 'Express STOP'. The game ends automatically and you are brought back to the table screen for this ended game.
# Switch to your game folder, go into the img folder and overwrite your game_box.png file with another image.
# Go back to your browser, '''empty your browser cache''', then refresh the page, and check that the game box image has been updated.

Then you can modify the provided skeleton and begin to develop your game :)

== Commit your changes ==

Committing uploads your changes on BGA's [http://en.wikipedia.org/wiki/Revision_control revision control] system. This is an extra assurance not to lose your code, and to have the possibility to get a previous version of your code if you need to backtrack. It also helps us to follow your progress (we get an email when you commit). So you should commit from time to time, when you hit some landmark in your development.

You can automatically commit your sources in the repository from "Control Panel / Manage Games / Your game / Commit my modifications now". Then:

# Enter your commit comment (such as 'My first commit') then hit the 'Submit' button;
# Check the log for errors, it should end with the following lines:

Transmitting file data .
Committed revision #revision number#.
HAL says: done.

NOTE: committing the code is currently not working until admin commits it manually the first time. Even if it does you cannot automatically deal with this version control system except for committing. Therefore its recommended to use another means of storing the code in version control system, such as local git repo or github, see [[Tools_and_tips_of_BGA_Studio#Version_Control|Version Control]]

== That's all! ==

Now you know about the basics of updating your game on BGA Studio and testing your changes.

Now you can select one of the tutorials to play with and start coding.

For links to tutorials and ALL studio documentation see [[Studio]].

[[Category:Studio]]