Engines using the 'Simple JavaScript Inheritance' implementation.

[tyson]

Hey all,   I'm invested using Cocos2-HTML5 and while it's a great engine, I wondering on how to port my code to another engine some day.

 

Are there many other engines using John Resig's implementation? http://ejohn.org/blog/simple-javascript-inheritance/

 

For example, a simple touchable sprite:

var PirateSprite = cc.Sprite.extend({    ctor: function() {       this.initWithFile("images/pirate.png");    },    init : function() {        this._super();    },    onEnter : function() {        this._super();        // add touch listener        cc.Director.getInstance().getTouchDispatcher().addTargetedDelegate(this, 1, true);    },    onExit : function() {        this._super();        // remove touch listener        cc.Director.getInstance().getTouchDispatcher().removeDelegate(this, 1, true);    },    onTouchBegan : function(touches, event) {       if (this.containsTouchLocation(touches)) {           GameUtils.explodeFireworksAt(cc.Rect.CCRectGetMidX(this.getBoundingBox()), cc.Rect.CCRectGetMidY(this.getBoundingBox()));           this.removeFromParent(true);       }    },    containsTouchLocation : function(touch) {         var p = this.getParent().convertTouchToNodeSpace(touch);        return cc.Rect.CCRectContainsPoint(this.getBoundingBox(), p);    }});

Thanks!

 

Tyson

[xerver]

I used it for a while, but found it was difficult to integrate other libraries into it. Using ECMAScript 5 `Object.defineProperty` and `Object.create` worked out much better for me.

[rich]

That style of syntax sends shivers down my spine

[Quetzacotl]

That style of syntax sends shivers down my spine

what flaws this syntax has? IMHO it's ok, easy to maintain and read. I know immediately what is going on in this code.

[Felipe]

Why not use prototype for inheritance ? It's really simple.

For the touch events you could create your own "input manager" that checks when a touch event is triggered. After that check if the x and y coords are inside the bounding box of the element, if so then fire a custom event for that element.

[Quetzacotl]

it does use prototype for inheritance underneath

[Felipe]

I know, but I was saying that for if he wants to port his code to his own engine or other that doesn't use that inheritance system underneath.

[PixelPicoSean]

There are some engines using that class system, such as Joy.js and impact.js, the syntax I think is very clear and straight forward. Especially using a module system like impact.js, it'll be much better. I dont think it's hard to port even to pure prototype inheritance.

[YellowAfterlife]

There are multiple engines using this type of syntax, though it is more common for ones to have a function extend(parent, fields). However, you can even save yourself from changing these little bits of code by adding a extend() method into the Function prototype itself:

Function.prototype.extend = function extend(fields) {	function inherit() {};	inherit.prototype = this;	var proto = new inherit();	for (var name in fields) proto[name] = fields[name];	return proto;}

To be executed before everything else.

Implementation courtesy of Haxe JavaScript generator.