title: What does this.ngIf in an Angular directive's controller do?
body: <p>I've got a controller function set in <code>directive's</code> <code>return</code> statement like this: <code>controller: elementCtrl</code>.</p>
  
  <p>Inside this function I've got a weird (simplified) example where <code>ct.ngIf = false;</code> is set.</p>
  
  <pre><code>function elementCtrl($scope, $element) {
      var ct = this;
  
      $document.on('click', function() {
          ct.ngIf = false;
      });
  }
  </code></pre>
  
  <p>Directive is <code>Element</code> type and on directive <code>ng-if</code> is applied. But the problem is that I do not understand what is this and how it works, and couldn't find any doc example of that usage.</p>
  
  <p>And what's more, is it possible for me to use other Angular core directives like <code>ngShow = false</code> this way?</p>