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    <p>You're right, it has to do with the fact that you're defining a function inside another function, then using it to handle events.</p> <p>Each time the function <code>upload</code> is called, it creates a new <a href="http://en.wikipedia.org/wiki/Closure_(computer_science)" rel="nofollow noreferrer">closure</a>, and assigns a reference to it to the <code>dispatchEvent</code> variable, which is then passed to the <code>addEventListener</code> class. So each time <code>upload</code> is called, it is using a new, <em>different</em> closure in the call to <code>addEventListener</code>. Similarly, in the <code>clearFileUploadListeners</code> function, a new closure is being created on each call (which happens to have the same code each time, but isn't the same function object). The call to <code>removeEventListener</code> does nothing if the given callback has not been added as an event listener for the given event, which is the case here.</p> <p>To solve your problem, you need to store a reference to the closure that you pass to the <code>addEventListener</code> function. This way, you can get a reference to the same closure that was added when you need to remove it later in <code>clearFileUploadListeners</code>.</p> <p>You can try something along the lines of the following code (untested):</p> <pre><code>import flash.utils.Dictionary; var callbackRegistry:* = new Dictionary(); private function upload(file:FileReference, index:String):void { var dispatchEvent:Function = generateFileUploadCompleteCallback(); callbackRegistry[file] = dispatchEvent; file.addEventListener(Event.COMPLETE, dispatchEvent); } private function clearFileUploadListeners(file:FileReference, index:String):void { var dispatchEvent:Function = callbackRegistry[file]; callbackRegistry[file] = null; file.removeEventListener(Event.COMPLETE, dispatchEvent); var bool:Boolean = file.hasEventListener(Event.COMPLETE); if (bool) trace("ERROR"); else trace("YAY, ALL OK!"); } private function generateFileUploadCompleteCallback(index:String):Function { return function(event:Event):void { dispatch(event.type, event, index); }; } </code></pre>
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    1. COThanks a lot, super clear explanation, I understand. I like your solution, it's very close to the one I had in mind (I defined a removeListeners() function inside my upload function, and stored it to an object). IE: object.var = removeListeners; then object.var(); It's similar to yours, I don't have to bother keeping track of a Dictionary but rather use the stack. Thanks for your help!
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    2. COGlad to have helped :-)
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