have you considered using ngModel for this directive two make it participate in the form validation?

I built a directive like this here: https://github.com/IgorMinar/foodme/blob/master/app/js/directives/fmRating.js

the downside is that due to the isolate scope you have to use $parent when binding the model :-( https://github.com/IgorMinar/foodme/blob/master/app/views/menu.html#L18