Watch for changing properties in Flex
In AS3 there is a handy utility class called ChangeWatcher, which lives inside the mx.binding.utils package. It provides you with a handy way of watching other object’s properties.
Here’s how it’s used:
- the object which owns the property
- the property you want to watch
- the function name of the handler
Whenever the property of the object changes, the handler will respond. Quite handy, right?
Here’s an example. Let’s say we have a class called WatchMe. Inside that class we have a public variable called ImBeingWatched. We’d like to trigger a function whenever this variable changes. To do this, we simply add one line of code:
The property that ChangeWatcher is watching must be [Bindable] and Public for it to work.