Unless you make the localizedHeaderText method bindable, the binding will never be re-evaluated since it does not know about the change event of the resourceManager.
Assuming you are in a UIComponent subclass, you'll need to do the following:
- override resourcesChanged and dispatch a custom event
- add [Bindable(event="customEvent")] above the method
Sample code:
override protected function resourcesChanged():void {
super.resourcesChanged();
dispatchEvent(new Event("localeChange"));
}
and
[Bindable(event="localeChange")]
public function localizedHeaderText(key:String):String {
return resourceManager.getString('resources', key);
}