Let’s say you created a new component and you want to add some properties that need to be bindable. Something like this:
<flexer:myComp width="400" height="200" myNewSetter="{_myData}" />
<mx:Script>
[Bindable]
private var _myData:String= "";
</mx:Script>
And when we do this
_myData = "new_val_1";
the myComp component should know that _myData has changed and should modify itself [...]