title: Gettings reference to existing navigation controller in tab bar after receiving remote notification
body: <p>My app consists of following:</p>
  
  <ul>
  <li>Tab bar controller with 5 tabs (this is my init controller)</li>
  <li>each tab bar item has navigation controller and another view controllers further in</li>
  </ul>
  
  <p>Now, I'm implementing skype-like chat (table view with contacts and chat as a detail view of this table view), which is currently residing in my second tab bar item, about 2 views deep in hierarchy.</p>
  
  <p>When I receive remote notification, I want to preserve user navigation stack in all tabs, so instead of recreating tab bar in appdelegate, I just want to get reference of my navigation controller, that is in my second tab (so that I can modify it's navigation stack later on).</p>
  
  <p>My problem here is, that I just can't get the reference. I got my tab bar like:</p>
  
  <pre><code>UITabBarController *myTabBar = (UITabBarController *)self.window.rootViewController;
  </code></pre>
  
  <p>but then I don't have any clue what to do. I will be happy for any suggestion.</p>