as3 air check if file is loaded

Question

How can I run code then the array is ready?

When I run the following code I get an error saying: TypeError: Error #1010: A term is undefined and has no properties.

import flash.filesystem.File;

var desktop:File = File.applicationDirectory.resolvePath("sounds/drums");

var sounds:Array = desktop.getDirectoryListing();

for (var i:uint = 0; i < sounds.length; i++)
   {
    trace(sounds[i].nativePath); // gets the path of the files
    trace(sounds[i].name);// gets the name
   }


var mySound:Sound = new Sound();
var myChannel:SoundChannel = new SoundChannel();
mySound.load(new URLRequest("sounds/drums/"+sounds[i].name+""));
myChannel = mySound.play();

Answer 1

I usually use something like the below, each time a sound is loaded it is stored and a counter is incremented, once all sounds are loaded you can dispatch an event or start playing any of the sounds stored in loadedSounds.

var sounds:Array = desktop.getDirectoryListing();

var loadedSounds:Object = {};
var soundsLoaded:int = 0;

for (var i:uint = 0; i < sounds.length; i++)
{
    var mySound:Sound = new Sound();
    mySound.addEventListener(Event.COMPLETE, onSoundLoaded);
    mySound.load(new URLRequest("sounds/drums/"+sounds[i].name));
}

private function onSoundLoaded(e:Event):void
{
    var loadedSound = e.target as Sound;
    // just get the file name without path and use it as key
    var lastIndex:int = loadedSound.url.lastIndexOf("/");
    var key:String = loadedSound.url.substr(lastIndex+1);

    // store sounds for later reference
    loadedSounds[key] = loadedSound ;

    soundsLoaded++;
    if (soundsLoaded == sounds.length)
    {
        //all sounds loaded, can start playing
    }
}