Introduction

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

Before you read this tutorial, you must:

• Read the overall presentations of the BGA Framework (see here).
• Know the rules for Hearts
• Some-what know the languages used on BGA: PHP, SQL, HTML, CSS, Javascript
• Set up your development environment First Steps with BGA Studio
• As part of setup you have to have access to your ftp home folder in studio, which would have the full 'hearts' game source code. We will be using some resources of this game in this tutorial, so copy it over to local disk if you have not done so.

If you are stuck or have question about this tutorial, post on BGA Developers forum

Create your first game

If you have not already, you have to create a project in BGA Studio. For this tutorial you can create a project heartsYOURNAME where YOURNAME is your developer login name. You can also re-use the project you have created for the "First Steps" tutorial above. With the initial skeleton of code provided, you can already start a game from the BGA Studio.

1. Find and express start the game in turn-based mode with 4 players. Make sure it works. If you want to see the game as 2nd player press red arrow button on the player panel to switch to that player. More details can be found in First_steps_with_BGA_Studio

2. Modify the text in heartsYOURNAME_heartsYOURNAME.tpl, reload the page in the browser and make sure your ftp sync works as expected. Note: if you have not setup auto-sync do it now, manually copying files is a no-starter.

3. Express stop from settings menu (the gear icon).

Note: please do not use the hearts project code as a base. This tutorial assumes you started with a TEMPLATE project with no prior modifications. Using the hearts project as a base will be very confusing and you won't be able to follow all the steps.

Attention!!! Very important note about reloading, if you don't remember this you may spend hours debugging. The browser caches images. If you change any of these files, you have to do "full reload" which is usually Ctrl+F5 (or Ctrl+reload button on browser) not just a regular reload.

Hook version control system

For a real game, or even for this tutorial, we recommend committing the code to version control right from the start. You are going to find yourself in a situation where the game doesn't even start anymore and no way of debugging it, unless you have a way to revert. That is where version control becomes very handy. If you are not familiar with version control (e.g. git) then at least back up your files after each major change. Start now.

Code for this tutorial available is on github: https://github.com/elaskavaia/bga-heartsla

Different revisions represent different steps along the process, starting from original template to a PARTIAL game.

The full game can be found in your FTP home folder, after getting read-only access: https://en.doc.boardgamearena.com/First_steps_with_BGA_Studio#Set_up_dev_environment_ide,_editor_and_File_Sync

Update game infos and box graphics

Even it does nothing yet, always start by making sure the game looks decent in the game selector, meaning it has nice box graphics and its information is correct. For that we need to edit gameinfos.inc.php.

For a real game, you would go to BoardGameGeek, find the game, and use the information from BGG to fill in the gameinfos.

So let's do that. Find "hearts" on BoardGameGeek. (Hint: Original release 1850 :))

You can fill in the year of publishing and bgg id, put Public Domain under publisher (for a real game, leave an empty string so it won't be displayed), and a publisher id of 171 for public domain. And as designer and author you can just put your own name just for fun. Set number of players to 4.

 // Players configuration that can be played (ex: 2 to 4 players)
 'players' => array( 4 ),  

Important step: you have to refresh the information in the Studio website through the control panel. So go to Control Panel -> Manage Games -> heartsYOURNAME and press Reload for 'Reload game informations'.

The next step would be to replace game_box.png with nicer images. This can be done from the Game metadata manager.

Now try to start the game again. If you somehow introduced a syntax error in the gameinfos file it may not work (the game won't start). Always use the "Express Start" button to start the game. You should see a standard state prompt from the template. You should see 4 players on the right: testdude0 .. testdude3. 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!

Note: if you had run the game before with less than 4 players there is a bug that will prevent you from running it with 4 only (if you did not run it before or run it with 4 players as instructed stop reading this note), to workaround revert back to original players array (i.e. 1,2,3,4), reload game options, then create a table with 4 players, exit that game table, then change gameoptions to 4 only as above, reload game options, create table again.

Code Rev [1]

Layout and Graphics

In this section we will do graphics of the game, and main layout of the game.

First copy a sprite with cards image from hearts img/cards.jpg into img/ folder of your project. Project hearts is mounted to your home directory on bga server.

There are better quality deck of cards image at https://en.doc.boardgamearena.com/Common_board_game_elements_image_resources

Details about images can be found here: Game art: img directory.

Edit .js to add some divs to represent player table and hand area, at the beginning of the setup function

document.getElementById('game_play_area').insertAdjacentHTML('beforeend', `
                <div id="myhand_wrap" class="whiteblock">
                    <b id="myhand_label">${_('My hand')}</b>
                    <div id="myhand"></div>
                </div>

            `);

If you refresh you should see now white area with My Hand title.

Now lets add a card into the hand, just so you can feel it. Edit .tpl and a playertablecard div inside a hand div

...
    <div id="myhand">
       <div class="playertablecard"></div>
    </div>
...

Edit .css file

.playertablecard {
    display: inline-block;
    position: relative;
    margin-top: 5px;
    width: 72px;
    height: 96px;
    background-image: url('img/cards.jpg'); /* temp hack to see it */
}

When you change existing graphics files remember that you have to FORCE-reload page, i.e. Ctrl-F5, otherwise its cached.

You should see this:

Awesome! Now lets do the rest of layout.

Let's complete the template string we created for the hand. Before the myhand div, add:

Change .tpl file to have this inside

<div id="playertables">
${
    Object.values(gamedatas.players).map((player, index) => `
    <div class="playertable whiteblock playertable_${DIRECTIONS[orderedPlayers.length][index]}">
        <div class="playertablename" style="color:#${player.color};"><span class="dealer_token" id="dealer_token_p${player.id}">🃏 </span>${player.name}</div>
        <div class="playertablecard" id="playertablecard_${player.id}"></div>
        <div class="playertablename" id="hand_score_wrap_${player.id}"><span class="hand_score_label"></span> <span id="hand_score_${player.id}"></span></div>
    </div>
    `).join('')
}
</div>

What we did is we added a template for every players at the table. For this new code to work, we need to add a constant at the beginning of the JS file, defining the expected position of each player :

const DIRECTIONS = {
    3: ['S', 'W', 'E'],
    4: ['S', 'W', 'N', 'E'],
};

Reload. If everything went well you should see this:

These are "tableau" areas for 4 players plus My hand visible only to one player. They are not exactly how we wanted them to be because we did not edit .css yet.

Now edit .css, add these lines after import before our previous definition

/** Table layout **/

#playertables {
    position: relative;
    width: 710px;
    height: 340px;
}

.playertablename {
    font-weight: bold;
}

.playertable {
    position: absolute;
    text-align: center;
    width: 180px;
    height: 130px;
}

.playertable_N {
    left: 50%;
    top: 0px;
    margin-left: -90px; /* half of 180 */
}
.playertable_S {
    left: 50%;
    bottom: 0px;
    margin-left: -90px; /* half of 180 */
}
.playertable_W {
    left: 0px;
    top: 50%;
    margin-top: -55px; /* half of 130 */
}
.playertable_E {
    right: 0px;
    top: 50%;
    margin-top: -55px; /* half of 130 */
}

Now you force Reload and you should see this:

This is almost all we need for graphics and layout, there are few tweaks left there but lets do some more heavy lifting now.

Note: if you did not see changes you may have not force reloaded, force means you use Ctrl+F5 or Cltr+Shift-R, if you don't "force" browser will use cached version of images! Which is not what you just changed

Another Note: In general if you have auto-sync you don't need to reload if you change Game.php file, you need normal reload if you change js, and force reload for images. If you changed state machine or database you likely need to restart the game.

Game Interface JS Stock

The BGA framework provides a few out of the box classes to deal with cards. The client side contains a class called Stock and it can be used for any dynamic html "pieces" management that uses common sprite images. On the server side we will use the Deck class which we discuss later.

If you open cards.jpg in an image viewer you will see that it is a "sprite" image - a 13x4 grid of images stitched together, which is a very efficient way to transport images. So we will use the Stock class to mark up these images and create "card" divs for us.

First, we need to add ebg/stock as a dependency in the hearts.js file:

define([
    "dojo","dojo/_base/declare",
    "ebg/core/gamegui",
    "ebg/counter",
    "ebg/stock"     /// <==== HERE
],

Then add this to the Javascript constructor, this will define size of our cards

            console.log('hearts constructor');
            this.cardwidth = 72;
            this.cardheight = 96;

The stock is initialized in the Javascript "setup" method like this:

    // TODO: Set up your game interface here, according to "gamedatas"

    // Player hand
    this.playerHand = new ebg.stock(); // new stock object for hand
    this.playerHand.create( this, $('myhand'), this.cardwidth, this.cardheight );

As parameters of the "create" method, we provided the width/height of an item (a card), and the container div "myhand" - which is an id of "div" element from our .tpl file representing a player hand.

Then, we must tell the stock what items it is going to display during its life: the 52 cards of a standard card game from a CSS sprite image named "cards.jpg" with all the cards arranged in 4 rows and 13 columns.

Here's how we tell stock what item types to display:

            this.playerHand.image_items_per_row = 13; // 13 images per row


            // Create cards types:
            for (var color = 1; color <= 4; color++) {
                for (var value = 2; value <= 14; value++) {
                    // Build card type id
                    var card_type_id = this.getCardUniqueId(color, value);
                    this.playerHand.addItemType(card_type_id, card_type_id, g_gamethemeurl + 'img/cards.jpg', card_type_id);
                }
            }

And add this function to the utilities section

        // Get card unique identifier based on its color and value
        getCardUniqueId : function(color, value) {
            return (color - 1) * 13 + (value - 2);
        },

Explanations:

• At first, we tell the stock component that our CSS sprite contains 13 items per row. This way, it can find the correct image for each card type id.
• Then for the 4x13 cards, we call the addItemType method that creates the type. The arguments are the type id, the weight of the card (for sorting purpose), the URL of our CSS sprite, and the position of our card image in the CSS sprite. It happens to be the same number in our case.

Note: we need to generate a unique ID for each type of card based on its color and value. For that we create a function getCardUniqueId. The type is the unique identifier of the TYPE of the card, e.g., the queen of spades encoded as an integer. If our deck had 2 standard card decks we would have had 2 queens of spades; they would share the same type and the same image but would have different ids. NOTE: It's unfortunate that they named this getCardUniqueId; it should have been getCardUniqueType, because it really isn't an id, but a TYPE of card. The type of the item should either be a reversible function of its properties (i.e., kind of suite * 13 + value) or just an enumerator described in material.inc.php. In this specific case it's a synthetic type id, which also the same as the number of the card in the sprite image (i.e., if you enumerate each image in sprite going left to right, then top to bottom).

Now let's add the 5 of Hearts to the player's hand just for fun (this code will go in setup method after types initialization):

// 2 = hearts, 5 is 5, and 42 is the card id, which normally would come from db
this.playerHand.addToStockWithId( this.getCardUniqueId( 2, 5 ), 42 );

This will add the card with id 42 and type 16 ( (2-1)*13+(5-2)=16 ).

Note that number 16 would not be something you can see in database, Deck database will have separate field for type and type_arg where type is suite and type_arg is number, so its not the same thing, but you can use same formula to convert. Number 42 on the other hand would be id field in database. But we get to database in the later section.

If you reload now you should see the 5 of hearts in "your hand".

Stock control can handle clicking on items and forms the selection. You can immediately react to selection or you can query it later; for example when user presses some other button.

Let's hook it up. Add this in the setup method in .js file, after this.playerHand is initialised:

    dojo.connect( this.playerHand, 'onChangeSelection', this, 'onPlayerHandSelectionChanged' );

Then find the Player's action comment section in .js file and add a handler after the comment:

        onPlayerHandSelectionChanged: function() {
            var items = this.playerHand.getSelectedItems();

            if (items.length > 0) {
                if (this.checkAction('actPlayCard', true)) {
                    // Can play a card

                    var card_id = items[0].id;
                    console.log("on playCard "+card_id);

                    this.playerHand.unselectAll();
                } else if (this.checkAction('actGiveCards')) {
                    // Can give cards => let the player select some cards
                } else {
                    this.playerHand.unselectAll();
                }
            }
        },

Note : If you already have an example handler onCardClick: function( card_id ), go ahead and remove that handler, it is a duplicate of what we are implementing in this tutorial and may cause issues later on.

The function name of the handler is 4th parameter of the dojo.connect function. Make sure you spell it correctly or there will be unpredictable effects.

Now if you reload, open the Javascript Console (F12), and then click on the card in My Hand, you should see:

 on playCard 42

printed on the console

Note : You need to be the active player to have rights to play a card and so log your message in the console

Game Database and Game Initialization

Next step, you want to design a game database and setup a new game (on the server side). For that we need to a) modify the database schema to add our cards data b) add some global variables into the existing globals table.

To modify the schema, first exit your existing game(s). Open dbmodel.sql file and uncomment the card table creation.

CREATE TABLE IF NOT EXISTS `card` (
  `card_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `card_type` varchar(16) NOT NULL,
  `card_type_arg` int(11) NOT NULL,
  `card_location` varchar(16) NOT NULL,
  `card_location_arg` int(11) NOT NULL,
  PRIMARY KEY (`card_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

This is the "card" table which will be managed by the Deck php class.

In addition we want a little piece of information in the players table:

 -- add info about first player
 ALTER TABLE `player` ADD `player_first` BOOLEAN NOT NULL DEFAULT '0';

Not sure why they put this into the player table, as we could use a global db variable to hold first player as easily. But I am just following the existing code more-or-less.

Next we finally get into Game.php class (in modules/php subdir), where the main logic and db interaction would be. Find php constructor which should be

 function __construct( )

This is first function in a file. Add this code to constructor.

        parent::__construct();
        $this->initGameStateLabels( array( 
                         "currentHandType" => 10, 
                         "trickColor" => 11, 
                         "alreadyPlayedHearts" => 12,
                          ) );

        $this->cards = $this->getNew( "module.common.deck" );
        $this->cards->init( "card" );

Here we are initializing three "Game State Variables" which are variables stored in the database. They are integers. It must start with values higher or equal to 10 since values lower than 10 are reserved. These values are stored by numeric ids in the database, but in the php we associate them with string labels for convenience of access.

The variables are:

• "trickColor": numbers from 1 to 4 that map to card suit (not sure why it's called color; maybe it's a translation from French);
• "alreadyPlayedHearts": a boolean flag (0 or 1) indicating whether somebody used hearts on the trick;
• "currentHandType": stores the value to indicate who to give cards to during exchange.

The next 2 lines are creating $this->cards object and associating it with "card" table in the the database.

If we called db table 'foo' instead of 'card' the last statement would have been $this->cards->init( "foo" )

At this point I would start a new game and make sure it starts, then exit.

Note: lower in the code there is a line that needs to be removed in order for the game to start. Search for it and remove it now.

$this->setGameStateInitialValue("my_first_global_variable", 0);

If you made a mistake in the .sql or php constructor the game won't start, and good luck debugging it. (That is why it's important to check once in a while to make sure it still starts while you remember what you have changed.)

Code Rev [2]

Now we can go to game initialization setupNewGame in Game.php. This method is called only once when the game is created.

In your template project you should have code that deals with player table, just leave it as is. Start inserting the other code after "Start the game initialization" comment.

        // Init global values with their initial values

        // Note: hand types: 0 = give 3 cards to player on the left
        //                   1 = give 3 cards to player on the right
        //                   2 = give 3 cards to player opposite
        //                   3 = keep cards
        $this->setGameStateInitialValue( 'currentHandType', 0 );
        
        // Set current trick color to zero (= no trick color)
        $this->setGameStateInitialValue( 'trickColor', 0 );
        
        // Mark if we already played hearts during this hand
        $this->setGameStateInitialValue( 'alreadyPlayedHearts', 0 );

Here we initialize all the globals to 0.

Next is to create our cards in the database. We have one deck of cards so it's pretty simple.

        // Create cards
        $cards = array ();
        foreach ( $this->colors as $color_id => $color ) {
            // spade, heart, diamond, club
            for ($value = 2; $value <= 14; $value ++) {
                //  2, 3, 4, ... K, A
                $cards [] = array ('type' => $color_id,'type_arg' => $value,'nbr' => 1 );
            }
        }
        
        $this->cards->createCards( $cards, 'deck' );

This code that will create one of each card. But don't run it yet, because we missing $this->colors. So we have state of the game in the database, but there is some static game information which never changes. This information should be stored in material.inc.php and this way it can be accessed from all .php files (and .js if you send it via getAllDatas()). We will edit this file now by adding these lines

$this->colors = array(
    1 => array( 'name' => clienttranslate('spade'),
                'nametr' => $this->_('spade') ),
    2 => array( 'name' => clienttranslate('heart'),
                'nametr' => $this->_('heart') ),
    3 => array( 'name' => clienttranslate('club'),
                'nametr' => $this->_('club') ),
    4 => array( 'name' => clienttranslate('diamond'),
                'nametr' => $this->_('diamond') )
);

$this->values_label = array(
    2 =>'2',
    3 => '3',
    4 => '4',
    5 => '5',
    6 => '6',
    7 => '7',
    8 => '8',
    9 => '9',
    10 => '10',
    11 => clienttranslate('J'),
    12 => clienttranslate('Q'),
    13 => clienttranslate('K'),
    14 => clienttranslate('A')
);

Where $this->colors will define Suit labels and $this->values_label will define value labels. If you noticed, we have two of each label for suits. This is because sometimes we need translated values on the php side and sometimes we don't. In this case nametr will return a translated value in php, which is only useful when you throw exceptions to show the right strings. If you pass a value to the client via notification you should always use untranslated strings, and the client will translate it. 'clienttranslate' marks the value for translation but does not actually change it for php. For more about this wonderful translation stuff see Translations.

Full game model synchronisation

Now at any point in the game we need to make sure that database information can be reflected back in the UI, so we must fix the getAllDatas function to return all possible data we need to reconstruct the game. This is in the Game.php file. The template for getAllDatas() already takes care of player info. Let's just add hand and tableau data before we return a result.

        // Cards in player hand
        $result['hand'] = $this->cards->getCardsInLocation( 'hand', $current_player_id );
        
        // Cards played on the table
        $result['cardsontable'] = $this->cards->getCardsInLocation( 'cardsontable' );

Now on the client side we should display this data, so in your .js file in the setup function (which is the receiver of getAllDatas) replace our hack of putting 5 of Hearts directly into the hand with:

            // Cards in player's hand
            for ( var i in this.gamedatas.hand) {
                var card = this.gamedatas.hand[i];
                var color = card.type;
                var value = card.type_arg;
                this.playerHand.addToStockWithId(this.getCardUniqueId(color, value), card.id);
            }

            // Cards played on table
            for (i in this.gamedatas.cardsontable) {
                var card = this.gamedatas.cardsontable[i];
                var color = card.type;
                var value = card.type_arg;
                var player_id = card.location_arg;
                this.playCardOnTable(player_id, color, value, card.id);
            }

This should show hand and tableau cards now, except we are missing the playCardOnTable function. So find the getCardUniqueId function which should be in the utilities section and add this after it:

        playCardOnTable : function(player_id, color, value, card_id) {
            // player_id => direction
            this.addTableCard(value, color, player_id, player_id);

            if (player_id != this.player_id) {
                // Some opponent played a card
                // Move card from player panel
                this.placeOnObject('cardontable_' + player_id, 'overall_player_board_' + player_id);
            } else {
                // You played a card. If it exists in your hand, move card from there and remove
                // corresponding item

                if ($('myhand_item_' + card_id)) {
                    this.placeOnObject('cardontable_' + player_id, 'myhand_item_' + card_id);
                    this.playerHand.removeFromStockById(card_id);
                }
            }

            // In any case: move it to its final destination
            this.slideToObject('cardontable_' + player_id, 'playertablecard_' + player_id).play();
        },

For this to work we also need to define the addTableCard

        addTableCard(value, color, card_player_id, playerTableId) {
            const x = value - 2;
            const y = color - 1;
            document.getElementById('playertablecard_' + playerTableId).insertAdjacentHTML('beforeend', `
                <div class="card cardontable" id="cardontable_${card_player_id}" style="background-position:-${x}00% -${y}00%"></div>
            `);
        },

What this does is basically create another card object, because if it is not our card it's not in our hand (Stock) so we have to create it out of thin air. The technique to do that is to implement a Javascript template object defined in the .tpl file with some parameters, which will basically create a "div" string (yes you could have used string concatenation but it would not be fancy). Now dojo.place places it (the div) on top of a placeholder. Now we have an object with an id of 'cardontable_' + player_id. Depending on who is playing it we either place it on the player miniboard or in hand (and remove it from hand stock). Then we animate the card move.

We also should fix our .css file now to add style for cardontable and REMOVE background for playertablecard which really is a placeholder div and not a card. (Don't miss the remove step; it will be all screwy if you do!)

.playertablecard {
    display: inline-block;
    position: relative;
    margin-top: 5px;
    width: 72px;
    height: 96px;
    /* we remove background-image here */
}

/*** cards on table ***/

.cardontable {
    position: absolute;
    width: 72px;
    height: 96px;
    background-image: url('img/cards.jpg'); 
}

Now to test that it actually works let's deal cards to players during game initialization:

Add this after createCards in setupNewGame function in the Game.php file

        // Shuffle deck
        $this->cards->shuffle('deck');
        // Deal 13 cards to each players
        $players = $this->loadPlayersBasicInfos();
        foreach ( $players as $player_id => $player ) {
            $cards = $this->cards->pickCards(13, 'deck', $player_id);
        } 

Now when you start the game you should see 13 cards in your hand!

We just need to hook-up clicking on card and test if our playCardOnTable works.

Find onPlayerHandSelectionChanged function in the JS file, we should have logging there like console.log("on playCard "+card_id); So after that insert this (Note: this code is for testing we will replace it with server interaction after we test it.):

                    console.log("on playCard "+card_id);
                    // type is (color - 1) * 13 + (value - 2)
                    var type = items[0].type;
                    var color = Math.floor(type / 13) + 1;
                    var value = type % 13 + 2;
                    
                    this.playCardOnTable(this.player_id,color,value,card_id);

Now if you force reload (because we changed .css before) you should be able to click on card from your hand and see it moving, you can click on few cards this way. When you done enjoying the animation, press F5 to get your hand back.

Code Rev [3]

State Machine

Now we need to create a game state machine. So the states are (excluding two more states we will add later to handle the exchange of cards at the beginning of the rounds):

• Cards are dealt to all players (lets call it "newHand")
• Player is selected who will start a new trick ("newTrick")
• Player start or respond to played card ("playerTurn")
• Game control is passed to next player or trick is ended ("nextPlayer")
• End of hand processing (scoring and check for end of game) ("nextHand")

The state handling spread across 4 files, so you have to make sure all pieces are connected together. The state machine states.php defines all the states, and function handlers on php side in a form of string, and if any of these functions are not implemented it would be very hard to debug because it will break in random places.

So .states.php

$machinestates = array(

    // The initial state. Please do not modify.
    1 => array(
        "name" => "gameSetup",
        "description" => clienttranslate("Game setup"),
        "type" => "manager",
        "action" => "stGameSetup",
        "transitions" => array( "" => 2 )
    ),
    
    
    /// New hand
    2 => array(
        "name" => "newHand",
        "description" => "",
        "type" => "game",
        "action" => "stNewHand",
        "updateGameProgression" => true,   
        "transitions" => array( "" => 30 )
    ),    

    21 => array(       
        "name" => "giveCards",
        "description" => clienttranslate('Some players must choose 3 cards to give to ${direction}'),
        "descriptionmyturn" => clienttranslate('${you} must choose 3 cards to give to ${direction}'),
        "type" => "multipleactiveplayer",
        "action" => "stGiveCards",
        "args" => "argGiveCards",
        "possibleactions" => array( "actGiveCards" ),
        "transitions" => array( "giveCards" => 22, "skip" => 22 )        
    ), 
    
    22 => array(
        "name" => "takeCards",
        "description" => "",
        "type" => "game",
        "action" => "stTakeCards",
        "transitions" => array( "startHand" => 30, "skip" => 30  )
    ),        
      
    
    // Trick
    
    30 => array(
        "name" => "newTrick",
        "description" => "",
        "type" => "game",
        "action" => "stNewTrick",
        "transitions" => array( "" => 31 )
    ),       
    31 => array(
        "name" => "playerTurn",
        "description" => clienttranslate('${actplayer} must play a card'),
        "descriptionmyturn" => clienttranslate('${you} must play a card'),
        "type" => "activeplayer",
        "possibleactions" => array( "actPlayCard" ),
        "transitions" => array( "playCard" => 32 )
    ), 
    32 => array(
        "name" => "nextPlayer",
        "description" => "",
        "type" => "game",
        "action" => "stNextPlayer",
        "transitions" => array( "nextPlayer" => 31, "nextTrick" => 30, "endHand" => 40 )
    ), 
    
    
    // End of the hand (scoring, etc...)
    40 => array(
        "name" => "endHand",
        "description" => "",
        "type" => "game",
        "action" => "stEndHand",
        "transitions" => array( "nextHand" => 2, "endGame" => 99 )
    ),     
   
    // Final state.
    // Please do not modify.
    99 => array(
        "name" => "gameEnd",
        "description" => clienttranslate("End of game"),
        "type" => "manager",
        "action" => "stGameEnd",
        "args" => "argGameEnd"
    )

);

The full details on these fields are in Your_game_state_machine:_states.inc.php.

But basically we have Player states, in which a human player has to perform an "action" by pressing some button in the UI or selecting some game item, which will trigger js handler, which will do an ajax call to the server.

To make it run we have to define all the handler functions that we referenced in states, which are - one function for state arguments argGiveCards, 4 functions for robot states (where the game performs some action) and 1 function for player actions handling. In Game.php, find 'Game state arguments' section and paste this in:

    function argGiveCards() {
        return array ();
    }

This normally passes some parameters to states, but we don't need anything yet. It's good to have a placeholder there anyway, so we can fix it later. Important: even when it's a stub, this function must return an array not a scalar.

Let's do stubs for other functions, find the game state actions section in Game.php file and insert these

    function stNewHand() {
        // Take back all cards (from any location => null) to deck
        $this->cards->moveAllCardsInLocation(null, "deck");
        $this->cards->shuffle('deck');
        // Deal 13 cards to each players
        // Create deck, shuffle it and give 13 initial cards
        $players = $this->loadPlayersBasicInfos();
        foreach ( $players as $player_id => $player ) {
            $cards = $this->cards->pickCards(13, 'deck', $player_id);
            // Notify player about his cards
            $this->notifyPlayer($player_id, 'newHand', '', array ('cards' => $cards ));
        }
        $this->setGameStateValue('alreadyPlayedHearts', 0);
        $this->gamestate->nextState("");
    }

    function stNewTrick() {
        // New trick: active the player who wins the last trick, or the player who own the club-2 card
        // Reset trick color to 0 (= no color)
        $this->setGameStateInitialValue('trickColor', 0);
        $this->gamestate->nextState();
    }

    function stNextPlayer() {
        // Active next player OR end the trick and go to the next trick OR end the hand
        if ($this->cards->countCardInLocation('cardsontable') == 4) {
            // This is the end of the trick
            // Move all cards to "cardswon" of the given player
            $best_value_player_id = $this->activeNextPlayer(); // TODO figure out winner of trick
            $this->cards->moveAllCardsInLocation('cardsontable', 'cardswon', null, $best_value_player_id);
        
            if ($this->cards->countCardInLocation('hand') == 0) {
                // End of the hand
                $this->gamestate->nextState("endHand");
            } else {
                // End of the trick
                $this->gamestate->nextState("nextTrick");
            }
        } else {
            // Standard case (not the end of the trick)
            // => just active the next player
            $player_id = $this->activeNextPlayer();
            $this->giveExtraTime($player_id);
            $this->gamestate->nextState('nextPlayer');
        }
    }

    function stEndHand() {
        $this->gamestate->nextState("nextHand");
    }

Important: All state actions game or player must end with state transition (or thrown exception). Also make sure it's ONLY one state transition, if you accidentally fall through after state transition and do another one it will be a real mess and head scratching for long time.

Now find 'player actions' section and paste this code there

    function actPlayCard(int $card_id) {
        $player_id = $this->getActivePlayerId();
        throw new \BgaUserException($this->_("Not implemented: ") . "$player_id plays $card_id");
    }

We won't implement it yet but throw an exception which we will see if interaction is working properly

Now the game should start but it would not be any different than before because we have to implement actual interactions. It's good to check if it's still working though (and if it was running before you have to exit because we changed state machine and normally it will break stuff). NOTE: When you play a card, you will not yet get the "Not implemented" message. That is added in the next section.

Client - Server interactions

Now to implement things for real we have hook UI actions to ajax calls, and process notifications sent by the server. So previously we hooked playCardOnTable right into js handler which caused client animation, in real game its a two step operation. When user clicks on game element js client sends an ajax call to server, server processes it and updates database, server sends notification in response, client hooks animations to server notification.

So in .js code replace onPlayerHandSelectionChanged with

        onPlayerHandSelectionChanged : function() {
            var items = this.playerHand.getSelectedItems();

            if (items.length > 0) {
                var action = 'actPlayCard';
                if (this.checkAction(action, true)) {
                    // Can play a card
                    var card_id = items[0].id;                    
                    this.bgaPerformAction(action, {
                        card_id : card_id,
                    });

                    this.playerHand.unselectAll();
                } else if (this.checkAction('actGiveCards')) {
                    // Can give cards => let the player select some cards
                } else {
                    this.playerHand.unselectAll();
                }
            }
        },

Now when you click on card you should get a server response: Not implemented...

Lets implement it, in Game.php

    function actPlayCard(int $card_id) {
        $player_id = $this->getActivePlayerId();
        $this->cards->moveCard($card_id, 'cardsontable', $player_id);
        // XXX check rules here
        $currentCard = $this->cards->getCard($card_id);
        // And notify
        $this->notifyAllPlayers('playCard', clienttranslate('${player_name} plays ${value_displayed} ${color_displayed}'), array (
                'i18n' => array ('color_displayed','value_displayed' ),'card_id' => $card_id,'player_id' => $player_id,
                'player_name' => $this->getActivePlayerName(),'value' => $currentCard ['type_arg'],
                'value_displayed' => $this->values_label [$currentCard ['type_arg']],'color' => $currentCard ['type'],
                'color_displayed' => $this->colors [$currentCard ['type']] ['name'] ));
        // Next player
        $this->gamestate->nextState('playCard');
    }

We get the card from client, we move it to the table (moveCard is hooked to database directly, its part of deck class), we notify all players and we change state. What we are missing here is bunch of checks (rule enforcements), we will add it later.

Interesting part about this notify is that we use i18n array for strings that needs to be translated by client, so they are sent as English text in notification, then client has to know which parameters needs translating.

On the client side .js we have to implement a notification handler to do the animation

        setupNotifications : function() {
            console.log('notifications subscriptions setup');

            const notifs = [
                ['newHand', 1],
                ['playCard', 100],
            ];
    
            notifs.forEach((notif) => {
                dojo.subscribe(notif[0], this, `notif_${notif[0]}`);
                this.notifqueue.setSynchronous(notif[0], notif[1]);
            });

        },

        notif_newHand : function(notif) {
            // We received a new full hand of 13 cards.
            this.playerHand.removeAll();

            for ( var i in notif.args.cards) {
                var card = notif.args.cards[i];
                var color = card.type;
                var value = card.type_arg;
                this.playerHand.addToStockWithId(this.getCardUniqueId(color, value), card.id);
            }
        },

        notif_playCard : function(notif) {
            // Play a card on the table
            this.playCardOnTable(notif.args.player_id, notif.args.color, notif.args.value, notif.args.card_id);
        },

Now it actually works through the server when you click on card - the move is recorded. If you test it now you will notice after trick is done all cards remains on the table, but if you press F5 they would disappear, this is because we updated database to pick-up the cards but did not send notification about it, so we need to send notification about it and have a handler for it

So in Game.php file add notification in stNextPlayer function after moveAllCardsInLocation call:

            // Notify
            // Note: we use 2 notifications here in order we can pause the display during the first notification
            //  before we move all cards to the winner (during the second)
            $players = $this->loadPlayersBasicInfos();
            $this->notifyAllPlayers( 'trickWin', clienttranslate('${player_name} wins the trick'), array(
                'player_id' => $best_value_player_id,
                'player_name' => $players[ $best_value_player_id ]['player_name']
            ) );            
            $this->notifyAllPlayers( 'giveAllCardsToPlayer','', array(
                'player_id' => $best_value_player_id
            ) );

And in .js file add 2 more notification handlers.

This is to subscribe in setupNotifications function

            const notifs = [
                ...
                ['trickWin', 1000],
                ['giveAllCardsToPlayer', 600],
            ];

And these are handlers

        notif_trickWin : function(notif) {
            // We do nothing here (just wait in order players can view the 4 cards played before they're gone.
        },
        notif_giveAllCardsToPlayer : function(notif) {
            // Move all cards on table to given table, then destroy them
            var winner_id = notif.args.player_id;
            for ( var player_id in this.gamedatas.players) {
                var anim = this.slideToObject('cardontable_' + player_id, 'overall_player_board_' + winner_id);
                dojo.connect(anim, 'onEnd', function(node) {
                    dojo.destroy(node);
                });
                anim.play();
            }
        },

So 'trickWin' notification does not do much except it will delay the processing of next notification by 1 second (1000 ms) and it will log the message (that happens independently of what handler does). Note: if on the other hand you don't want to log but want to do something else, send an empty message

Now after the trick you see all cards move towards the "player's stash".

Scoring and End of game handling

Now we should calculate scoring and for that we need to actually track who wins the trick. Trick is won by the player with highest card (no trump). We just need to remember what is trick suite. For which we will use state variable 'trickColor' which we already conveniently created.

In Game.php file find the playCard function and add this before notify functions

       $currentTrickColor = $this->getGameStateValue( 'trickColor' ) ;
       if( $currentTrickColor == 0 )
           $this->setGameStateValue( 'trickColor', $currentCard['type'] );

This will make sure we remember the first suit being played, now to use it modify the stNextPlayer function to fix our TODO comment

    function stNextPlayer() {
        // Active next player OR end the trick and go to the next trick OR end the hand
        if ($this->cards->countCardInLocation('cardsontable') == 4) {
            // This is the end of the trick
            $cards_on_table = $this->cards->getCardsInLocation('cardsontable');
            $best_value = 0;
            $best_value_player_id = null;
            $currentTrickColor = $this->getGameStateValue('trickColor');
            foreach ( $cards_on_table as $card ) {
                // Note: type = card color
                if ($card ['type'] == $currentTrickColor) {
                    if ($best_value_player_id === null || $card ['type_arg'] > $best_value) {
                        $best_value_player_id = $card ['location_arg']; // Note: location_arg = player who played this card on table
                        $best_value = $card ['type_arg']; // Note: type_arg = value of the card
                    }
                }
            }
            
            // Active this player => he's the one who starts the next trick
            $this->gamestate->changeActivePlayer( $best_value_player_id );
            
            // Move all cards to "cardswon" of the given player
            $this->cards->moveAllCardsInLocation('cardsontable', 'cardswon', null, $best_value_player_id);
        
            // Notify
            // ... same code here as before

The scoring rule in the studio example code is huge multi-page function, for this tutorial we will make simplier. Lets score -1 point per heart and call it a day. And game will end when somebody goes -100 or below.

As UI goes for scoring, the main thing to update is the scoring on the mini boards represented by stars, also we want to show that in the log. In addition scoring can be shown in Scoring Dialog using tableWindow notification, but it is a tutorial on its own and you can do it as homework (it is part of original heart game).

In .js file we need to add one more subscription and notification handler:

            const notifs = [
                ...
                ['newScores', 1],
            ];

in setupNotifications

and

       notif_newScores : function(notif) {
           // Update players' scores
           for ( var player_id in notif.args.newScores) {
               this.scoreCtrl[player_id].toValue(notif.args.newScores[player_id]);
           }
       },

somewhere after. this.scoreCtrl is pre-existing object that shows the scoring and this function will update score values per player from notification argument

so in Game.php our stEndHand function will look like

    function stEndHand() {
            // Count and score points, then end the game or go to the next hand.
        $players = $this->loadPlayersBasicInfos();
        // Gets all "hearts" + queen of spades

        $player_to_points = array ();
        foreach ( $players as $player_id => $player ) {
            $player_to_points [$player_id] = 0;
        }
        $cards = $this->cards->getCardsInLocation("cardswon");
        foreach ( $cards as $card ) {
            $player_id = $card ['location_arg'];
            // Note: 2 = heart
            if ($card ['type'] == 2) {
                $player_to_points [$player_id] ++;
            }
        }
        // Apply scores to player
        foreach ( $player_to_points as $player_id => $points ) {
            if ($points != 0) {
                $sql = "UPDATE player SET player_score=player_score-$points  WHERE player_id='$player_id'";
                $this->DbQuery($sql);
                $heart_number = $player_to_points [$player_id];
                $this->notifyAllPlayers("points", clienttranslate('${player_name} gets ${nbr} hearts and looses ${nbr} points'), array (
                        'player_id' => $player_id,'player_name' => $players [$player_id] ['player_name'],
                        'nbr' => $heart_number ));
            } else {
                // No point lost (just notify)
                $this->notifyAllPlayers("points", clienttranslate('${player_name} did not get any hearts'), array (
                        'player_id' => $player_id,'player_name' => $players [$player_id] ['player_name'] ));
            }
        }
        $newScores = $this->getCollectionFromDb("SELECT player_id, player_score FROM player", true );
        $this->notifyAllPlayers( "newScores", '', array( 'newScores' => $newScores ) );

        ///// Test if this is the end of the game
        foreach ( $newScores as $player_id => $score ) {
            if ($score <= -100) {
                // Trigger the end of the game !
                $this->gamestate->nextState("endGame");
                return;
            }
        }

        
        $this->gamestate->nextState("nextHand");
    }

So it should more less work now, including end of game condition. Try to play it!

Additional stuff

The following things were not implemented and can add them yourself by looking at the code of original hearts game:

• Remove debug code from setupNewGame to deal cards, cards are now dealt in stNewHand state handler
• Rule checking and rule enforcements in playCard function
• Start scoring with 100 points each and end when <= 0
• Fix scoring rules with Q of spades and 26 point reverse scoring
• First player one with 2 club
• Add progress handling
• Add statistics
• Add card exchange states
• Add game option to start with 75 points instead of 100