Unable to have Flash Component (SWC) access the library in live preview - actionscript-3

Question

I am building a set of Flash components with the ability to replace the skin of the component with another one in the library.
Currently, I am able to access the library after running the application, but not during live preview and I'd like to know if it is possible for the component to access the library while running in live preview mode (the mode where you can drag the component around the stage and change its properties in the Component Parameters window)
Here is a simplified code that just looks to see if there is a symbol of the name specified and than instantiates it and adds it as a child.
package
{
import fl.core.UIComponent;
import flash.display.MovieClip;
import flash.system.ApplicationDomain;
/**
* ...
* #author Roy Lazarovich
*/
public class CompTest extends UIComponent
{
private var customfile :String;
public function CompTest()
{
}
override protected function configUI():void
{
}
override protected function draw():void
{
super.draw();
}
private function setCustomFile():void
{
if (ApplicationDomain.currentDomain.hasDefinition(customfile))
{
var c:Class = Class(ApplicationDomain.currentDomain.getDefinition(customfile));
var mc:MovieClip = new c();
addChild(mc);
}
}
[Inspectable(name = "_Custom File", defaultValue = "")]
public function set _customfile(value:String):void
{
customfile = value;
setCustomFile();
drawNow();
}
}
}
Thanks!

Answer 1

I'm not entirely sure what you have already tried to fix this situation. But hopefully this might help.
Right click on the MovieClip in your library, select Linkage and give it a class name, ie. MyThing.
In your code,
newMyThing = new MyThing();
this.addChild(newMyThing);
trace("tada!");
Hope that helps or gets you closer to a solution.

Answer 2

This works for me in LivePreview, as long as I apply it in configUI, and not draw:
public class EditableBitmap extends UIComponent
{
protected var placeholder:String = "None";
protected var bitmap:Bitmap;
protected var scale:Number = 1;
[Inspectable(name = "Placeholder", type = String, defaultValue="None")]
public function set Placeholder($value:String):void
{
placeholder = $value;
configUI();
}
public function get Placeholder():String { return placeholder; }
public function EditableBitmap()
{
//Console.Debug("NEW EditableBitmap");
super();
}
override protected function configUI():void
{
//Console.Debug("EditableBitmap configUI: " + width);
if (!isNaN(width))
{
wDim = width;
hDim = height;
graphics.clear();
graphics.beginFill(0x000000, 0.1);
graphics.drawRect(0, 0, wDim, hDim);
}
if (placeholder != "None" && placeholder != "")
{
var asset:Class = getDefinitionByName(placeholder) as Class;
var data:BitmapData = new asset() as BitmapData;
bitmap = new Bitmap(data);
}
super.configUI();
}
override protected function draw():void
{
if (bitmap)
{
addChild(bitmap);
bitmap.x = off_x * scale;
bitmap.y = off_y * scale;
bitmap.scaleX = bitmap.scaleY = scale;
}
}
}
NOTE: When I'm working on the FLA where I am editing the component, the bitmap is only displayed from the library inconsistenty. Sometimes it works, sometimes it doesn't. But when I export the SWC and then import the component to another movie, it works every time, in LivePreview as well as at runtime.
UPDATE
It seems this doesn't work in CS6 unless the symbol is already embedded in the component .SWC I wanted to see if I could trick it, by embedding one image in the SWC and then replacing it with another of the same name in the destination file. This didn't work, but it did point me to how you can do this:
So, it's a bit laborious, but you could work around this by:
1) Creating a dummy asset for each property in the component SWC.
2) Overriding this using a custom class in the file where you deploy the component
... all of which may be more trouble than it's worth, but which should provide a solution to the problem.