title: Updates Labels in Swift when using popoverController
body: <p>I have a question about swift,</p>
  
  <p>I made a popover controller in a UIViewController,which display a list of books
  and when the user click on one of the books, the label on the viewController should be updated with the name of the selected book.</p>
  
  <p>But in my case when I select a name of a book, the label does not update</p>
  
  <p>here is the code :</p>
  
  <pre><code>// View Controller
  
  import UIKit
  
  class ViewController: UIViewController,UIPopoverControllerDelegate {
      var popoverController : UIPopoverController? = nil
      @IBOutlet var bookName : UILabel
      var BookNameString : String?{
      didSet{
          configureView()
      }
      }
  
      func configureView() {
          // Update the user interface for the detail item.
          if let detail = self.BookNameString {
              if let label = bookName {
                  label.text = detail
              }
          }
      }
      override func viewDidLoad() {
          super.viewDidLoad()
          // Do any additional setup after loading the view, typically from a nib.
      }
      @IBAction func Click(sender : UIButton) {
          var tableView:TableViewController = TableViewController(style: UITableViewStyle.Plain)
          var popoverContent:UINavigationController = UINavigationController(rootViewController: tableView)
          self.popoverController = UIPopoverController(contentViewController: popoverContent)
          self.popoverController!.delegate = self
          self.popoverController!.presentPopoverFromRect(sender.frame, inView: self.view, permittedArrowDirections: UIPopoverArrowDirection.Any, animated: true)
      }
  
      override func didReceiveMemoryWarning() {
          super.didReceiveMemoryWarning()
          // Dispose of any resources that can be recreated.
      }
  }
  </code></pre>
  
  <p>and here is the code of the TableViewController when a row is selected:</p>
  
  <pre><code>// TableViewController
  
  override func tableView(tableView: UITableView!, didSelectRowAtIndexPath indexPath: NSIndexPath!){
  
      var storyboard = UIStoryboard(name: "Main", bundle: nil)
      var details = storyboard.instantiateViewControllerWithIdentifier("ViewController") as ViewController
  
  
      var keyString = bookSectionKeys[indexPath.section]
      var bookValues = book.booksLetters[keyString]!
      var selectedBookString = bookValues[indexPath.row]
      var selectedBookValues = book.bookDictionary[selectedBookString]!
  
      details.BookNameString = selectedBookString
  
  
  }
  </code></pre>