[flexcoders] Best way to defer sub-component initialization?

[Sascha]

Not sure if the subject makes complete sense but what would be the best way
to defer setting properties on a sub component when writing custom Flex
components without getting a null reference? Let's say I create a custom
component that wraps another component, for example a button ...

package
{
        class Foo extends Panel
        {
                protected var _closeButton:Button;
                protected var _hasCloseButton:Boolean;
                
                public function Foo()
                {
                        super();
                }
                
                public function set hasCloseButtton(v:Boolean):void
                {
                        _hasCloseButton = v;
                }
                
                override protected function createChildren():void
                {
                        super.createChildren();
                        
                        if (_hasCloseButton)
                        {
                                _closeButton = new Button();
                                addChild(_closeButton);
                        }
                }
        }
}


There are two ways that I know how to get the close button, either in an
extending class in the overriding createChildren method set _hasCloseButton
= true _and then_ call super.createChildren() or the other way by listening
for a creationComplete event and defer/handle the instantiation of the close
button from there on.

But I think these two ways are sub-optimal so I was wondering how others
solve this problem and what works best in every situation?

Thanks for any advice!
Sascha