Using isolate scope is more angularific

Michael, what you have seems to work pretty well, but it's more idiomatic angular code to take advantage of a feature of angular directives called isolate scopes. Isolate scopes let you map elements of the surrounding scope in which your directive is used onto the directive's scope. By using the "=" I am telling angular to create a two way binding from the rating property of the surrounding scope to the value property of the directive scope, but without a prototype relationship. In the watch, we can just watch the value attribute of the current scope then, as it is bound to the surrounding scope's rating property automatically.