title: how to specify redirection ZF2 constructor?
body: <p>I am working on login module in my current project. For accessing profile page user must logged in. For that i am checking login status against session in constructor. if user not logged in page should redirect to log in page.</p>
  
  <p>following is psedo code.</p>
  
  <pre><code>    use Zend\Mvc\Controller\AbstractActionController;
      use Zend\View\Model\ViewModel;
      class StatisticsController extends AbstractActionController
      {
      // variables ------
          public function __construct()
          {
             if(!isset($_SESSION['admin_email']))
             {
              $this-&gt;redirect()-&gt;toUrl('/admin');
             }
          }
      }
  </code></pre>
  
  <p>Above code gives following error message</p>
  
  <pre><code>Redirect plugin requires event compose a response
  </code></pre>
  
  <p>Thanks in advance</p>