Question

In Actionscript 3 I could add a method to an object dynamically.
like to below code

var s:Sprite = new Sprite()
var f:Function = function(){this.graphic.clear()}
s.clean = f

could I create another Sprite instance with the clean function from s ?

Answer 1

It is possible using the prototype of Sprite :

Sprite.prototype.clean = function():void { trace("works"); }
var s1:Sprite = new Sprite();
var s2:Sprite = new Sprite();
s1["clean"]();
s2["clean"]();

Of course this adds clean to all the instances of Sprite you create, if that’s not what you want you could just create a function to create sprites and use that.

function createSprite():Sprite
{
   var s:Sprite = new Sprite();
   var f:Function = function(){this.graphic.clear()}
   s.clean = f ;
   return s;
}

If you don’t want to alter the Sprite class your other option is inheritance and adding the clean method to this new class :

public class MySprite extends Sprite
{
   public function clean():void
   {
      this.graphic.clear();
   }
}

var s1:MySprite = new MySprite();
s1.clean();