Is it possible to load a non-Document Class before preloader starts? - actionscript-3

Question

public class Framework extends MovieClip
{
var _loadingSystem:LoadingSystem;
public function Framework()
{
_loadingSystem = new LoadingSystem(this);
loaderInfo.addEventListener(ProgressEvent.PROGRESS,progressHandler);
loaderInfo.addEventListener(Event.COMPLETE, completeListener);
}
...
public class LoadingSystem extends MovieClip
{
public function LoadingSystem(parent:DisplayObjectContainer)
{
parent.addChild(this);
myLogo.buttonMode = true;
myLogo.addEventListener(MouseEvent.CLICK, gotoMySite);
}
As you can see, Framework is my Doc class which is creating _loadingSystem which is basically a movieclip that contains the preloader graphics. When I debug I get the following error "TypeError: Error #1009: Cannot access a property or method of a null object reference." pointing to myLogo.buttonMode = true;
From what I understand this is due to LoadingSystem not being fully loaded before being created in Framework. Is there any way for me to make this work? I have tried adding listeners for Event.ADDED but it didn't work.
Additional info: 3-frame FLA, first empty with a stop, second holding an AssetHolder movieclip, third for the application. I have export on 2nd frame set in publishing settings, all checkboxes for export on 2nd frame unchecked in the assets, and this all worked before I changed the export on 2nd frame setting except it wasn't preloading 50% of the file.

Answer 1

i think what's happening is this:
A document class is ALWAYS loaded in the first frame, because it represents your swf root class and thus has to be there in the first frame. Now, since you export all the other classes to frame 2, i would imagine, that LoadingSystem is existing only beginning with frame two, but you try to instantiate it in the constructor of your document class Framework.
What you could try out is, create a method "initialize" in Framework and call that from the timeline in frame 2. And in that method you would do the stuff, you currently do in the constructor of Framework.

Answer 2

if myLogo is a sprite/movieclip on the stage, it wont exist until LoadingSystem is added to the stage.
Now your first reaction should be "but I added it to the stage with parent.addChild(this)!". What you didn't take into account is that the document class isn't on the stage when the constructor is called. Flash basically executes like this:
docClass = new DocumentClass();
stage.addChild(docClass);
Which means that the stage property of the document class will be null until after the constructor is finished. It also means that any children added during the constructor wont have access to the stage or objects located on the stage until after the docClass is added to the stage.
There is a simple fix; listen for the ADDED_TO_STAGE event.
public function LoadingSystem(parent:DisplayObjectContainer)
{
parent.addChild(this);
addEventListener(Event.ADDED_TO_STAGE, initialize);
}
private function initialize(e:Event):void
{
removeEventListener(Event.ADDED_TO_STAGE, initialize);
addEventListener(Event.REMOVED_FROM_STAGE, uninitialize);
//attach stage listeners etc
myLogo.buttonMode = true;
myLogo.addEventListener(MouseEvent.CLICK, gotoMySite);
}
private function uninitialize(e:Event):void
{
removeEventListener(Event.REMOVED_FROM_STAGE, uninitialize);
addEventListener(Event.ADDED_TO_STAGE, initialize);
//detach stage listeners etc.
}