Why ngModel's $render is not called when the model changes in AngularJS?

Question

DEMO

Why in the following example $render is not called when the button is clicked?

Answer 1

The input directive is running after your directive and thus it's $render function is replacing yours.

Set your directive's priority to something greater than 0. For instance:

.directive("phoneNumber", function() {
  return {
    restrict: 'A',
    require: 'ngModel',
    priority: 1,
    link: function(scope, element, attrs, ngModel) {
      ngModel.$render = function() {
        alert('rendering');
      };
    } 
  };
});

And your $render will take precedence and you'll see your alert is called.