Please take a look at this jsfiddle.
I'm trying to create a "widget" that will allow the user to select either a $ or % sign and format a text field accordingly. I've got it working, sort of, but it's not updating the underlying model properly.
Can someone please point out what I'm missing?
This occur because a bug(at least I think) with isolated scopes, see this working without an isolated scope
Have you considered using a filter?
Something along these lines?