How to fire a event for Array push? [Flash]

Question

How would I go about as to addEventListener for a array object.

I'm trying to avoid running a timer every x milliseconds to check for new elements in array object, rather trying to make a event fire when new elements are detected to process them and remove them.

Is it possible with Arrays? maybe ArrayCollections? either is fine.

P.S.> This is Flash question not javascript

score 1 · Accepted Answer · answered Aug 17 '10 at 23:52

Why not create your own array class that extends Array and implements the IEventDispatcher, override the push() function and make it dispatch an event when the function is called?

So something like:

package
{
    import flash.events.EventDispatcher;
    import flash.events.IEventDispatcher;

    public class MyArray extends Array implements IEventDispatcher
    {
        public static var ARRAY_PUSHED:String = "MYARRAY_ARRAY_PUSHED";

        private var dispatcher:EventDispatcher;

        public function MyArray(...parameters)
        {
            super(parameters);
            dispatcher = new EventDispatcher(this);
        }

        override public function push(...parameters):uint
        {
            dispatchEvent(ARRAY_PUSHED);
            super.push(parameters);
        }

        public function addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int=0, useWeakReference:Boolean=false):void
        {
            dispatcher.addEventListener(type, listener, useCapture, priority);
        }
        public function dispatchEvent(e:Event):Boolean
        {
            return dispatcher.dispatchEvent(e);
        }
        public function hasEventListener(type:String):Boolean
        {
            return dispatcher.hasEventListener(type);
        }
        public function removeEventListener(type:String, listener:Function, useCapture:Boolean=false):void
        {
            dispatcher.removeEventListener(type, listener, useCapture);
        }
        public function willTrigger(type:String):Boolean
        {
            return dispatcher.willTrigger(type);
        }
    }
}

well this fails, the event pased to the listeners do not point to de array that dispath the event, and the code is far of working — Delta, Sep 24 '10 at 04:43

score 0 · Answer 2 · edited May 23 '17 at 12:04

0

How about extending the Array.prototype.push method? Stolen from How to extend Array.prototype.push()?

Array.prototype.push=(function(){
    var original = Array.prototype.push;
    return function() {
        //Do what you want here.
        return original.apply(this,arguments);
    };
})();

Throw any code that you want inside of the inner function body.

edited May 23 '17 at 12:04

Community

1
1

answered Aug 17 '10 at 19:42

meder omuraliev

183,342
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yes thats good to know. Doubt I'll do this in javascript though looking for flash/actionscript advise on this matter – SSpoke Aug 17 '10 at 19:48
Can't you override it in Actionscript though? Since the core of AS is ECMAScript. – meder omuraliev Aug 17 '10 at 19:49
seems like you may have found the best answer :P – SSpoke Aug 17 '10 at 19:54

score 0 · Answer 3 · answered Aug 17 '10 at 19:55

0

found

 AS3 override function push(...args):uint
    {
        for (var i:* in args)
        {
            if (!(args[i] is dataType))
            {
                args.splice(i,1);
            }
        }
        return (super.push.apply(this, args));
    }

with meder's help

answered Aug 17 '10 at 19:55

SSpoke

5,656
10
72
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Although I cannot really use this as this overrides the whole push system for array object but i have different array's doing push I just want to target one of them. – SSpoke Aug 17 '10 at 20:07

score 0 · Answer 4 · answered Aug 18 '10 at 02:41

   private var myArray:Array;

   private function addToArray(element:Object):void
   {
        myArray.push(element);
        dispatch( new Event("Element added));
   }

or in a static function if you wanted to call this from another class

   public static function addToArray( array:Array , element:Object , dispatcher:EventDispatcher):Array
   {
       array.push(element);
       dispatcher.dispatch( new Event('Added Element') );
       return array;
   }

The implementation really depends on your environment.

How to fire a event for Array push? [Flash]

4 Answers4