Binding to a Models isDirty?

I want to mark a form as "dirty", that is, whenever the Model.isDirty is true I want to both enable a button and show some text.

Is it possible to bind to that property? Or do I have to go about a formula? And if either or neither of the aforementioned; what is your recommendation?

I can't imagine this isn't covered, and I think I'm just missing something.