title: Angular Directive - NgModelCtrl Parser Issue
body: <p>I have a directive to show a symbol depending on the value of a field. This is attached to a field as follows:</p>
  
  <pre><code>&lt;input type="text" placeholder="" class="text-input" ng-class="example_class" ng-model="exmaple-model" my-directive /&gt;
  </code></pre>
  
  <p>And a directive as follows:</p>
  
  <pre><code>module.directive("myDirective", function () {
      return {
          require: "?ngModel",
  
          link: function (scope, element, attrs, ngModelCtrl) {
              /*breakpoints show the line above and below are reached*/
              ngModelCtrl.$parsers.push(function (val) {
                  /* call to function to show symbol, this line is never reached */
              }
  </code></pre>
  
  <p>The code is reaching the <code>ngModelCtrl</code> line, but reaches no further. Debugging has shown that while the <code>ngModelCtrl</code> looks to be built correctly (has functions and values, etc.) the <code>$parsers</code> is empty - the length is 0, the functions that should be there aren't. </p>
  
  <p>Looking at the Chrome inspector yields no errors. Are there any reasons for the <code>$parsers</code> to be blank, or is there a way to debug the directive any further?</p>