Flex: Listening for CollectionEvent in custom component

Answer 1

Why don't you just do this:

public function set xlist(x:XMLList):void {

   _xlist = new XMLListCollection(x);
   _all.label = 'All (' + _xlist.length + ')';

   var full:XMLList = _xlist.source.game.(user.length() == 3);
   _full.label = 'Full (' + full.length() + ')';

   var free:XMLList = _xlist.source.game.(user.length() < 3);
   _free.label = 'Free (' + free.length() + ')';

}

You don't need a listener if the only way to set the local _xlist variable is by setting the xlist property.

Answer 2

Two things:

1) The reason your event is not firing is because you are adding the listener after you set _xlist.

2) You should not be adding an event listener within your setter anyways. You should add it on the initialize or creationComplete events of your VBox component.

EDIT

Alright, after looking at your code again I can see the problem... so just a few more things.

3) Why are you naming a method init, when it gets called on creationComplete? You should get into the habit of naming methods appropriately. For example, the method that gets called on creationComplete should be named: onCreationComplete, or handleCreationComplete That way, you will know what your code is doing 6 months down the road.

4) This is your main problem: You are using the getters / setters in appropriately. If you have a setter, you should also implement a getter (unless you have a write-only field). More importantly, you should use the getter to access your data. In your xListChanged method you are not using the setter you have defined, thus nothing is getting told the _xlist actually changed. As such, you should change your code to:

private var _xlist:XMLListCollection;

[Bindable]
public function get xlist():XMLListCollection { return this._xlist; }
public function set xlist(value:XMLListCollection):void
{
    this._xlist = value;
}

Whenever you want to access _xlist, use the GETTER. For example, change the dataProvider of your List component to be {xlist}. And the xListChanged method should be using the getter: xlist instead of directly accessing the member _xlist.