Firebase Cloud Messaging iOS: No background push notification

Question

Using the newer Firebase cloud messaging with method swizzling i am successfully able to receive a payload in the didReceiveRemoteNotification method in my app delegate when my app is foregrounded. However i do not get any sort of payload and didReceiveRemoteNotification does not get called when my app is backgrounded, despite the api response that the message is successfully sent (see below)
Here is the request that i send to the FCM api to trigger a push notification https://fcm.googleapis.com/fcm/send

{
"to": "{valid-registration-token}",
"priority":"high", //others suggested setting priority to high would fix, but did not
  "notification":{
      "body":"Body3",
      "title":"test"  
 } 
}

with response from FCM

{
      "multicast_id": 6616533575211076304,
      "success": 1,
      "failure": 0,
      "canonical_ids": 0,
      "results": [
        {
          "message_id": "0:1468906545447775%a4aa0efda4aa0efd"
        }
      ]
    }

Here is my appDelegate code

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

        Fabric.with([Crashlytics.self])
        FIRApp.configure()

        NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(self.tokenRefreshNotification),
                                                         name: kFIRInstanceIDTokenRefreshNotification, object: nil)
        return true
    }



    func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject], fetchCompletionHandler completionHandler: (UIBackgroundFetchResult) -> Void) {
        // Let FCM know about the message for analytics etc.
        FIRMessaging.messaging().appDidReceiveMessage(userInfo)

        // Print full message.
        print("%@", userInfo)

        // handle your message

//        let localNotification = UILocalNotification()
//        localNotification.fireDate = NSDate()
//        let notification = userInfo["notification"]!
//        localNotification.alertBody = notification["body"] as? String
//        localNotification.alertTitle = notification["title"] as? String
//        localNotification.timeZone = NSTimeZone()
//        application.scheduleLocalNotification(localNotification)

    }

    func tokenRefreshNotification(notification: NSNotification) {
        let refreshedToken = FIRInstanceID.instanceID().token()!
        print("InstanceID token: \(refreshedToken)")
        LoginVC.registerForPushNotifications()
        connectToFcm()
    }


    //foreground messages
    func applicationDidBecomeActive(application: UIApplication) {
        connectToFcm()
    }

    // [START disconnect_from_fcm]
    func applicationDidEnterBackground(application: UIApplication) {
        FIRMessaging.messaging().disconnect()
        print("Disconnected from FCM.")
    }


    func connectToFcm() {
        FIRMessaging.messaging().connectWithCompletion { (error) in
            if (error != nil) {
                print("Unable to connect with FCM. \(error)")
            } else {
                print("Connected to FCM.")
            }
        }
    }

}

I call this code at a later flow in my app to ask for permissions

static func registerForPushNotifications() {
    let settings: UIUserNotificationSettings =
                UIUserNotificationSettings(forTypes: [.Alert, .Badge, .Sound], categories: nil)
            UIApplication.sharedApplication().registerUserNotificationSettings(settings)
            UIApplication.sharedApplication().registerForRemoteNotifications()
}

Since i am able to receive notifications while app is foregrounded i assume this would allay all concerns that my apns certificates are not uploaded or that the registration token is incorrect. If that is not the case, please comment and i'll go down that rabbit hole again. There's probably something simple that i am overlooking, but how can i get the notifications to appear while the app is backgrounded? Thanks

I am facing a similar struggle today: the handler in app delegate is called, when the application is in the foreground, but no tray notification appears, when the app is in the background. Interesting to see if anything turns up. Will let you know if I figure this out. — Kazimieras
When your app is in the foreground you can receive messages directly from FCM not through APNs which is what is used when your app is in the background. To be sure that APNs is configured correctly could you confirm that you are receiving an APNs token by implementing the didRegisterForRemoteNotificationsWithDeviceToken method. — Arthur Thompson
@ArthurThompson Before this version of the code, i was not using the method swizzling technique and did implement the didRegisterForeRemoteNotificationsWIthDeviceToken method where i was able to get a token. At first i'd hoped i was done, but when this token didn't work for FCM i had to refactor. Does that answer your question? — Daniel George
@Kazimieras Yes i read the whole thing. I tried setting priority to high and content-available to true. but no luck. I also tried using both at the same time. but others have said that that will not work, and in my case that was again true. — Daniel George

Daniel George Daniel George · Accepted Answer · 2016-07-20T04:29:55

Apparently, (despite using method swizzling that should be doing it automatically) you must still set the APNS token on the Firebase Instance. Consequently this means you must also implement the didRegisterForRemoteNOtificationsWithDeviceToken method with something like

func application(application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: NSData) {


        // set firebase apns token
        FIRInstanceID.instanceID().setAPNSToken(deviceToken, type: FIRInstanceIDAPNSTokenType.Unknown)
}

As an added note. Using "priority":"high" was useful for testing as it sent the notification right away.

Firebase Cloud Messaging iOS: No background push notification

7 Answers