Flash CS5 reference a display object in the constructor of a non-document class

Question

After learning of this excellent method of accessing an object placed on the stage in Flash CS5 in a class other than the document class (found in this thread), I have run into

Answer 1

stage is a property of DisplayObject only accessible/defined once it has been added to the DisplayList (ie - added to something via addChild())

You won't have any luck accessing stage from a class constructor unless it's the document class.

As mentioned, you can shift the contents of your constructor to a custom function which is called once Event.ADDED_TO_STAGE has been triggered.

For example, here's a demo class:

public class Thing extends DisplayObject
{
    /**
     * Constructor
     */
    public function Thing()
    {
        // Add listener
        addEventListener(Event.ADDED_TO_STAGE, _added);
    }

    /**
     * Called once this has been added to the display list
     * @param e Event.ADDED_TO_STAGE
     */
    private function _added(e:Event):void
    {
        // Discard listener
        removeEventListener(Event.ADDED_TO_STAGE, _added);

        // My initial code
        trace(stage + " is accessible");
    }
}

Which we then create an instance of:

var thing:Thing = new Thing(); // nothing happens

And then add to the stage/current container:

addChild(thing); // output: [Object Stage] is accessible

As for accessing greenLight1, this should be achievable easily via either of the following:

stage.greenLight1;
stage["greenLight1"];

Also, you might want to replace:

public function Player(stage:Object):void

With:

public function Player(stage:Stage):void