Group and foreach

[arknoid]

Hi , 

I m  new user of phaser and i develop a retro shoot them up for the  GameOFF jam .

i  have a problem in  my  game state  :

  enemyTween: function(){

    this.enemyPool.forEachAlive(function(enemy){
      enemyTween = this.game.add.tween(enemy)
    })

 

TypeError: this.game is undefined
[En savoir plus]

 

why i cant acces to game and other event into function of group?

 

(sorry for my bad english)

[mattstyles]

I'm not sure how `enemyPool` or the `forEachAlive` function works but often this sort of thing is a scoping issue (although the error you've reported is slightly wrong for a scope issue).

The problem is that JS is sometimes a little unexpected for scoping and so any time you use a class or object you have to work with `this`, which is a common cause of issue.

In your case I think that (maybe) you should just scope the callback function, you have some options here:

this.enemyPool.forEachAlive(function(enemy){
  enemyTween = this.game.add.tween(enemy)
}, this)

Notice the following `this` after the function declaration, usually the `forEachAlive` function can accepts another parameter that defines scope.

You can also do this explicitly by calling `bind` yourself:

this.enemyPool.forEachAlive(function(enemy){
  enemyTween = this.game.add.tween(enemy)
}.bind(this))

`bind` sets the `this` of a function.

You have another potential issue though:

enemyTween: function(){
 this.enemyPool.forEachAlive(function(enemy){
   enemyTween = this.game.add.tween(enemy)
 })
}

You're overwriting `enemyTween`, hard to tell without seeing the rest of the code but its probably bad.

[arknoid]

 

Thank you very much, it works well with "this". desolate if I ask stupid questions but I started with javascript and phaser, furthermore I find that the documentation lacks concrete example and detail.

 

I will soon have new questions to ask you but for the moment I try to unraveled myself

 

 

[mattstyles]

2 hours ago, arknoid said:

desolate if I ask stupid questions

Deffo not a stupid question, JS scoping can be a little misleading, or, surprising, particularly if you come with any knowledge from real classical languages.

There is another option using arrow functions:

.forEach(item => {
  // do something
})

However, some libraries will try to scope your function (using .bind usually) so it won't always work as expected. Also also, arrow function scoping is even more confusing.

[samme]

2 hours ago, arknoid said:

furthermore I find that the documentation lacks concrete example and detail.

• https://photonstorm.github.io/phaser-ce/Phaser.Group.html#forEachAlive
• http://phaser.io/examples/v2/category/groups

[arknoid]

thank for all i dont know this Api : https://photonstorm.github.io/phaser-ce/index.html

[arknoid]

I have a problem again, I want to setup group in create event and call number of  each later (with timer)

setupEnemies:function(){
    this.asteroidPool = this.add.group();
    this.bigAsteroidPool = this.add.group();
    this.tiePool = this.add.group();
    this.interceptorPool = this.add.group();
    this.enemyPool = this.add.group();
    this.enemyPool.enableBody = true;
    this.enemyPool.physicsBodyType = Phaser.Physics.ARCADE;
  },
addEnemies: function(nbrTie,nbrAsteroid,nbrBigAsteroid,nbrInterceptor) {

    /***************************************************************************
     * Asteroid
     *
     ***************************************************************************/

    this.asteroidPool.createMultiple(nbrAsteroid, 'asteroid');
    this.asteroidPool.createMultiple(nbrAsteroid, 'asteroid2');
    this.asteroidPool.createMultiple(nbrAsteroid, 'asteroid3');
    this.asteroidPool.forEach(function(child) {
      child.name = "asteroid"
      child.animations.add('idle', [0]);
      child.animations.add('hit', [0, 1, 0, 1], 20, false);
      child.events.onAnimationComplete.add(function(e) {
        e.play('idle');
      }, this);
      child.name = "asteroid";
    });
    /***************************************************************************
     * bigAsteroid
     *
     ***************************************************************************/

    this.bigAsteroidPool.createMultiple(nbrBigAsteroid, 'bigAsteroid');
    this.bigAsteroidPool.forEach(function(child) {
      child.name = "bigAsteroid"
      child.animations.add('idle', [0]);
      child.animations.add('hit', [0, 1, 0, 1], 20, false);
      child.events.onAnimationComplete.add(function(e) {
        e.play('idle');
      }, this);
    });
    /***************************************************************************
     * tie
     *
     ***************************************************************************/

    this.tiePool.createMultiple(nbrTie, 'tie');
    this.tiePool.forEach(function(child) {
      child.name = "tie"
      child.animations.add('idle', [0, 1, 2, 3], 20, true);
      child.animations.add('hit', [0, 4, 0, 4], 20, false); //quand c'est finie retour sur idle
      child.events.onAnimationComplete.add(function(e) {
        e.play('idle');
      }, this);
    });
    /***************************************************************************
     * interceptor
     *
     ***************************************************************************/

    this.interceptorPool.createMultiple(nbrInterceptor, 'interceptor');
    this.interceptorPool.forEach(function(child) {
      child.name = "interceptor";
      child.animations.add('idle', [0, 1, 2], 20, true);
      child.animations.add('hit', [0, 3, 0, 3], 20, false); //quand c'est finie retour sur idle
      child.events.onAnimationComplete.add(function(e) {
        e.play('idle');
      }, this);
    });

    this.enemyPool.addMultiple(this.asteroidPool);
    this.enemyPool.addMultiple(this.tiePool);
    this.enemyPool.addMultiple(this.interceptorPool);
    this.enemyPool.addMultiple(this.bigAsteroidPool);
    this.enemyPool.setAll('anchor.x', 0.5);
    this.enemyPool.setAll('anchor.y', 0.5);
    this.enemyPool.setAll('outOfBoundsKill', true);
    this.enemyPool.setAll('checkWorldBounds', true);
  },

Create: function() {
    /************************************************************************************************
     *Initialize
     *
     ************************************************************************************************/
    this.setupBackground(); //Initialize Background (A completter)
    this.setupScaleMode(); //Initialize Sclaling and no blur
    this.setupEnemiesShot();
    this.setupEnemies(); //Initialize Enemies
    this.setupPlayerShot(); //Initialize Player Shot
    this.setupExplode(); //Initialize Explosion effets
    this.setupText(); //Initialize Text Screen
    this.setupPlayer(); //Initialize Player
    this.setupScore(); //Initialize text score
    this.setupLives(); //Initialize text lives
    this.addEnemies(1,10,2,1);

But nothing ...

Full source code here :

https://gitlab.com/Arknoid/The-lost-jedi/tree/Olivier