title: bindToController: Object in directives
body: <p>Directive <code>bindToController</code> can be either boolean or object, the latter is shown <a href="https://docs.angularjs.org/api/ngMock/service/$controller#example" rel="nofollow">here</a>:</p>
  
  <pre><code>myMod.directive('myDirective', {
    controller: 'MyDirectiveController',
    bindToController: {
      name: '@'
    }
  });
  </code></pre>
  
  <p>But the fact that it was not documented raises questions. Why <code>bindToController: { ... }</code> feature was made in the first place? Are there useful scenarios for it?</p>
  
  <hr>
  
  <p>Despite bindToController <a href="https://github.com/angular/angular.js/pull/10467#issuecomment-67050879" rel="nofollow">wasn't primarily intended</a> for that, it is interesting to see how it is utilized now in <code>angular.component</code> <a href="https://github.com/angular/angular.js/blob/v1.5.0-beta.2/src/loader.js#L382" rel="nofollow">as <code>bindings</code> property</a> to fill the gap between 1.5 and 2.0, while <code>scope</code> bindings remain unused. </p>