Question

I’m learning as3 and I’m having difficulties understanding events.

I’m trying to load options inside an array that I will later need to access to load images.

Now..

private function init(e:Event = null):void {

    removeEventListener(Event.ADDED_TO_STAGE, init);

    myLoader.load(new URLRequest("slides.xml"));
    myLoader.addEventListener(Event.COMPLETE, processXMLSlides);
    ...
}

private function processXMLSlides(e:Event):void {

    removeEventListener(Event.COMPLETE, processXMLSlides);

    myXML = new XML(e.target.data);
    myXML.ignoreWhite=true;

    for (var i:int = 0; i < myXML.IMAGE.length(); i++) {
        imagesURLs.push(myXML.IMAGE[i]);
        //trace(myXML.IMAGE[i]);
    }
    //Start the main routine.
    loadImages();
    writeImage(imageCurrent);
}

loadImages() takes the array imagesURLs and loads them inside another array as URLRequests and then writeImage() writes the image to the stage.

Now the thing is this. If I move the loadImages() and writeImage() function here:

   private function init(e:Event = null):void {

        removeEventListener(Event.ADDED_TO_STAGE, init);

        myLoader.load(new URLRequest("slides.xml"));
        myLoader.addEventListener(Event.COMPLETE, processXMLSlides);

            //Start the main routine.
        loadImages();
        writeImage(imageCurrent);
        ...
    }

It doesn’t work because loadImages gets called BEFORE the array gets populated from the xml. Now how can I tell as3 to wait for the processXMLSlides to finish its thing?
Do I need another event? Is this stupid (there are better ways to do what I’m doing)?

Thanks

Answer 1

Your question doesn’t make sense, your first example is doing exactly what you are asking for – waiting for the XML to be loaded.

Flash Events are very handy in handling asynchronous processes – like XML loading – how long would you wait otherwise before calling the loadImages(); and writeImage(imageCurrent);? The answer is exactly as long as it takes for the XML to load. So keep it where it is, in the event handler method.

NOTE:

Add the listener to myLoader first and call the load() method only afterwards. When testing on a local environment (from a hard drive) it can happen that the “slides.xml” will load immediately and the COMPLETE event will be fired before the eventListener is attached.