phaser/examples/groups/extending a group.js

window.onload = function() {

    //  Here is a custom group
    //  It will automatically create 30 sprites of the given image when created.

    MonsterGroup = function (game, image, action) {

        Phaser.Group.call(this, game);

        for (var i = 0; i < 30; i++)
        {
            var sprite = this.create(game.world.randomX, game.world.randomY, image);

            if (action == 'bounce')
            {
                game.add.tween(sprite).to({ y: sprite.y - 100 }, 2000, Phaser.Easing.Elastic.Out, true, 0, 1000, true);
            }
            else if (action == 'slide')
            {
                game.add.tween(sprite).to({ x: sprite.x + 200 }, 4000, Phaser.Easing.Elastic.Out, true, 0, 1000, true);
            }

        }

    };

    MonsterGroup.prototype = Object.create(Phaser.Group.prototype);
    MonsterGroup.prototype.constructor = MonsterGroup;

    var game = new Phaser.Game(800, 600, Phaser.CANVAS, 'phaser-example', { preload: preload, create: create });

    var customGroup1;
    var customGroup2;

    function preload() {

        game.load.image('ufo', 'assets/sprites/ufo.png');
        game.load.image('baddie', 'assets/sprites/space-baddie.png');
        
    }

    function create() {

        customGroup1 = new MonsterGroup(game, 'ufo', 'bounce');
        customGroup2 = new MonsterGroup(game, 'baddie', 'slide');

    }

}();