Instantiating MXML class in AS3

Question

I have a simple MXML component:
-- code -- 'MyClass'
<mx:Canvas ... creationPolicy="none" ... >
  <mx:HBox id="innerPanel" >
    <mx:Canvas ... />
  </mx:HBox>
</mx:Canvas>
-- /code --
I'm trying to instantiate this in AS3 as so:
-- code --
var myClass:MyClass = new myClass();
myClass.createComponentsFromDescriptors(true);
-- /code --
myClass is created, but no children.  myClass.childDescriptors is empty.
What am I doing wrong?
thanx,
rickb

Answer 1

Unfortunatelly nothing of the above works when you have a chain of MXML's and AS's that are instantiating eachother. Not even the combination of all of the techniques mentioned earlier.
I tried all of the above on the entire chain, and even placed callLater in the main canvas container but still creationComplete in MyMXML happens after callLater.
I tried to be creative with the bellow pseudo pseudo code, I hope you get the idea.
<MyMainCanvas>
<script>
onCreationComplete
var myClass = new MyClass();
addChild(myClass)
callLater(doSomething)
doSomething()
// does nothing as none of the properties are available from MyMXML
</script>
</MyMainCanvas>
MyClass extends Canvas
function MyClass()
  var myMXML = new MyMXML();
  addChild(myMXML);
<MyMXML>
<script>
onCreationComplete
   // this gets called after callLater in MyMainCanvas
</script>
</MyMXML>