title: Showing alert after unwind segue stops the segue. How do I make sure alert is shown after unwind segue is completed?
body: <p>I have an unwind segue from A view controller to B view controller. </p>
  
  <p>A network operation is done in B. After the operation is completed, the response will be shown in A view controller.</p>
  
  <p>I successfully made this structure. However there is an issue:</p>
  
  <p>When I try to show the alert, it shows but stops the segue. How do i make sure alert shows after segue is completed.</p>
  
  <p>The error is here:</p>
  
  <pre><code>2016-04-27 14:39:28.350 PROJECT[9100:128844] Presenting view controllers on detached view controllers is discouraged &lt;PROJECT.FeedTableViewController: 0x7a928c00&gt;.
  2016-04-27 14:39:28.359 PROJECT[9100:128844] popToViewController:transition: called on &lt;UINavigationController 0x7c12a800&gt; while an existing transition or presentation is occurring; the navigation stack will not be updated.
  </code></pre>
  
  <p>Unwind handler in A:</p>
  
  <pre><code>@IBAction func unwindToFeed(segue: UIStoryboardSegue) {
          jsonArray[rowFromShare!]["ApplicationDataUsers"] = jsonFromShare!
          tableView.reloadData()
          ShowErrorDialog("Success", message: successMessageFromShare!, buttonTitle: "OK")
      }
  
  //Error Dialog
  func ShowErrorDialog(title:String, message:String, buttonTitle:String){
      let alert = UIAlertController(title: title, message: message, preferredStyle: .Alert)
      alert.addAction(UIAlertAction(title: "OK", style: .Default) { _ in })
      self.presentViewController(alert, animated: true){}
  }
  </code></pre>
  
  <p>Unwind trigger in B:</p>
  
  <pre><code>override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
  
      if segue.identifier == "unwindToFeed"{
          let feedTable = segue.destinationViewController as! FeedTableViewController
          feedTable.rowFromShare = row
          feedTable.jsonFromShare = jsonToShare
          feedTable.successMessageFromShare = successMessageToShare
      }
  
      // Get the new view controller using segue.destinationViewController.
      // Pass the selected object to the new view controller.
  }
  </code></pre>
  
  <p>A = FeedTableViewController
  B = ShareTableViewController</p>
  
  <p>How do I make sure alert is shown after segue is done?</p>