title: Load UIViewController from the separate nib file in swift?
body: <p>I had take one ViewController with separate nib file. and my initial root viewcontroller is set in the storyBoard. Now the problem is that when I push to this controller the  View hireachy methods are not being called (ViewDidLoad , ViewWillApper , etc).. </p>
  
  <p><strong>Code</strong> (View is loaded but methods are not calling)</p>
  
  <pre><code>var viewController = UIViewController(nibName: "OfferDetailViewController", bundle: nil) as OfferDetailViewController
   self.navigationController?.pushViewController(viewController, animated: true);
  </code></pre>
  
  <p>The same thing if i do with the storyboard its working fine. </p>
  
  <pre><code>    let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
      var viewController = mainStoryboard.instantiateViewControllerWithIdentifier("offer") as OfferDetailViewController     
     self.navigationController?.pushViewController(viewController, animated: true);
  </code></pre>
  
  <p><strong>Problem</strong> : With storyboard View hierarchy methods are calling but not with the separate nib file?</p>