I also don't think a promise makes much sense, if we're talking about the same sort of widget. For a "selector", where the whole purpose is selecting a thing, I

I also don't think a promise makes much sense, if we're talking about the same sort of widget. For a "selector", where the whole purpose is selecting a thing, I think that even better than that would be to use ng-model (or something similar). Which nearly comes back full circle to the original $emitting an event scenario, except instead the other side would $watch (rather than $on, and avoiding the emit/broadcast part on the directive's side totally).