title: iOS using xib + global methods for overlay UIView (Swift)
body: <p>I'm writing an app that should present overlays in specific situations, like  for example the lack of location services enabled for the app.</p>
  
  <p>Overlay is a UIView with a UIImageView (background) a UILabel (title) and a UIButton calling a specific action. I want to use Interface Builder to set up the overlay UI but I would like to recall the overlay and show it on different UIViewControllers, depending on when the lack of location services is detected.</p>
  
  <p>I have set up a custom class (subclass of UIView) to link a xib file. Code below:</p>
  
  <pre><code>class LaunchCustomScreen: UIView
  {
  
     @IBOutlet var title: UILabel!
     @IBOutlet var enableLocationButton: UIButton!
     @IBOutlet var waitingIndicator: UIActivityIndicatorView!
     @IBOutlet var bckgroundImage: UIImageView!
  
     func setupDefault()
     {
         title.text = "Location Services Required"
         enableLocationButton.setTitle("Enable Location Services", forState: UIControlState.Normal)
         enableLocationButton.addTarget(self,
          action: "promptUserForLocation",
          forControlEvents: UIControlEvents.TouchUpInside)
  
         hideLocButton()
     }
  
     func hideLocButton()
     {
         enableLocationButton.hidden = true
     }
  
     func showLocButton()
     {
         enableLocationButton.hidden = false
     }
  }
  </code></pre>
  
  <p>Then I have created the xib file which is of Class LaunchCustomScreen and I linked the IBOutlets to all the objects in it (UILabels, UIBUtton, UIImageView)</p>
  
  <p>Then I have set some global functions to be called from any other UIViewController in order to show/hide the overlay on the specific view controller and configure it with UIButton hidden or visible (it will be hidden with a waiting indicator when user location is still loading). Below related code:</p>
  
  <pre><code>func setupLaunchDefault(vc: UIViewController) -&gt; LaunchCustomScreen
  {
      for aSubview in vc.view.subviews
      {
          if aSubview.isKindOfClass(LaunchCustomScreen)
          {
              NSLog("Found already a launch screen. Removing")
              aSubview.removeFromSuperview()
          }
      }
  
      var screen: LaunchCustomScreen = LaunchCustomScreen()
      screen.setupDefault()
      return screen
  }
  
  func showLaunchAskLocation(vc:UIViewController)
  {
      var screen = setupLaunchDefault(vc)
      screen.bounds = vc.view.bounds
      screen.showLocButton()
      vc.view.addSubview(screen)
  } 
  </code></pre>
  
  <p>Now I'm trying if the solution works and it crashes on the setupLaunchDefault function. Reason is that even if an instance of LaunchCustomSCreen is created, the variables (title, enableLocationButton) are still nil. I though they should be non-nil thanks to the IBOutlet to the xib... what am I missing?</p>
  
  <p>Thank you in advance for your help!</p>