title: IOS Swift Pushkit: didUpdatePushCredentials not called
body: <p>I am trying to develop a VoIP app using <a href="https://www.twilio.com/docs/api/client/ios" rel="nofollow noreferrer">Twilio Client iOS SDK</a>. My app receives incoming calls when its not in background. For background mode I am trying to use <code>PushKit Framework</code> as Apple suggests. But my app is not getting registered for <code>PushKit</code>. The method <code>didUpdatePushCredentials</code> is not getting called. </p>
  
  <p>This is my app delegate and settings:</p>
  
  <p><a href="https://i.stack.imgur.com/xvF4k.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xvF4k.png" alt="enter image description here"></a></p>
  
  <pre><code>import UIKit
  import PushKit;
  
  @UIApplicationMain
  class AppDelegate: UIResponder, UIApplicationDelegate {
  
      var window: UIWindow?
      var voipRegistry: PKPushRegistry!;
  
      func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -&gt; Bool {
          // Override point for customization after application launch.
  
  
          if  UIApplication.instancesRespondToSelector(#selector(UIApplication.registerUserNotificationSettings(_:))) {
              application.registerUserNotificationSettings(UIUserNotificationSettings(forTypes: [UIUserNotificationType.Alert, UIUserNotificationType.Badge, UIUserNotificationType.Sound], categories: nil))
          }
  
          let preferences = NSUserDefaults.standardUserDefaults()
          let usrIdKey = "usrId"
          let tokenKey = "token"
          if preferences.objectForKey(usrIdKey) == nil  || preferences.objectForKey(tokenKey) == nil{
              //  Doesn't exist
          } else {
  
              self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
              var nav1 = UINavigationController()
              let storyboard = UIStoryboard(name: "Main", bundle: nil)
              let viewControllerObj = storyboard.instantiateViewControllerWithIdentifier("NumberScreenViewController") as? NumberScreenViewController
              nav1.viewControllers = [viewControllerObj!]
              self.window!.rootViewController = nav1
              self.window?.makeKeyAndVisible()
          }
  
          phone.login{
              device in
          }
  
          var state:String
          switch application.applicationState {
          case .Active:
              state = "Active"
          case .Background:
              state = "Background"
          case .Inactive:
              state = "Active"
          }
  
          NSLog("App launched with state \(state)")
  
          return true
      }
  
      func applicationWillResignActive(application: UIApplication) {
          // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
          // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
      }
  
      func applicationDidEnterBackground(application: UIApplication) {
          // Use this method to release shared resources, save user data, invalidate timers, and store enough application state informationO to restore your application to its current state in case it is terminated later.
          // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
  
      }
  
      func applicationWillEnterForeground(application: UIApplication) {
          // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
      }
  
      func applicationDidBecomeActive(application: UIApplication) {
          // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
      }
  
      func applicationWillTerminate(application: UIApplication) {
          // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
          //output to see when we terminate the app
          NSLog("app terminated")
      }
  
      func application(application: UIApplication, didRegisterUserNotificationSettings notificationSettings: UIUserNotificationSettings) {
           NSLog("Registering for VOIP notifications.")
          //register for voip notifications
          voipRegistry = PKPushRegistry(queue: dispatch_get_main_queue())
          voipRegistry.desiredPushTypes = Set([PKPushTypeVoIP])
          voipRegistry.delegate = self;
      }
  
  
      func application(application: UIApplication, didReceiveLocalNotification notification: UILocalNotification)
      {
          if ( application.applicationState == UIApplicationState.Active)
          {
              print("Active")
              // App is foreground and notification is recieved,
              // Show a alert.
          }
          else if( application.applicationState == UIApplicationState.Background)
          {
              print("Background")
              // App is in background and notification is received,
              // You can fetch required data here don't do anything with UI.
              self.redirectToPage(notification.userInfo)
          }
          else if( application.applicationState == UIApplicationState.Inactive)
          {
              print("Inactive")
              // App came in foreground by used clicking on notification,
              // Use userinfo for redirecting to specific view controller.
              self.redirectToPage(notification.userInfo)
          }
      }
  
      func redirectToPage(userInfo:[NSObject : AnyObject]!)
      {
          var viewControllerToBrRedirectedTo:DialScreenViewController  = DialScreenViewController(nibName: "DialScreenViewController", bundle: nil)
          if userInfo != nil
          {
              if let pageType = userInfo["TYPE"]
              {
                  if pageType as! String == "Page1"
                  {
  //                    viewControllerToBrRedirectedTo = UIViewController() // creater specific view controller
                  }
              }
          }
  
              if self.window != nil &amp;&amp; self.window?.rootViewController != nil
              {
                  let rootVC = self.window?.rootViewController!
                  if rootVC is UINavigationController
                  {
                      (rootVC as! UINavigationController).pushViewController(viewControllerToBrRedirectedTo, animated: true)
                  }
                  else
                  {
                      rootVC?.presentViewController(viewControllerToBrRedirectedTo, animated: true, completion: { () -&gt; Void in
  
                      })
                  }
              }
      }
  }
  
  extension AppDelegate: PKPushRegistryDelegate {
  
      func pushRegistry(registry: PKPushRegistry!, didUpdatePushCredentials credentials: PKPushCredentials!, forType type: String!) {
  
          //print out the VoIP token. We will use this to test the nofications.
          NSLog("voip token: \(credentials.token)")
      }
  
      func pushRegistry(registry: PKPushRegistry!, didReceiveIncomingPushWithPayload payload: PKPushPayload!, forType type: String!) {
          let payloadDict = payload.dictionaryPayload["aps"] as? Dictionary&lt;String, String&gt;
          let message = payloadDict?["alert"]
  
          //present a local notifcation to visually see when we are recieving a VoIP Notification
          if UIApplication.sharedApplication().applicationState == UIApplicationState.Background {
  
              let localNotification = UILocalNotification();
              localNotification.alertBody = message
              localNotification.applicationIconBadgeNumber = 1;
              localNotification.soundName = UILocalNotificationDefaultSoundName;
  
              UIApplication.sharedApplication().presentLocalNotificationNow(localNotification);
          }
  
          else {
              dispatch_async(dispatch_get_main_queue(), { () -&gt; Void in
                  let alert = UIAlertView(title: "VoIP Notification", message: message, delegate: nil, cancelButtonTitle: "Ok");
                  alert.show()
              })
          }
  
          NSLog("incoming voip notfication: \(payload.dictionaryPayload)")
      }
  
      func pushRegistry(registry: PKPushRegistry!, didInvalidatePushTokenForType type: String!) {
  
          NSLog("token invalidated")
      }
  }
  </code></pre>