Correct way to retrieve token for FCM - iOS 10 Swift 3

Question

i had implement Firebase with FirebaseAuth/FCM etc and did sent notification successfully through Firebase Console.

However i would need to push the notification from m

Answer 1

First register for the firebase token refresh notification:

NotificationCenter.default.addObserver(self, selector: 
     #selector(tokenRefreshNotification), name:     
     NSNotification.Name.InstanceIDTokenRefresh, object: nil)

Then you can receive the token in the tokenRefreshNotification selector:

func tokenRefreshNotification(_ notification: Notification) {
    if let refreshedToken = FIRInstanceID.instanceID().token() {
      print("InstanceID token: \(refreshedToken)")
    }

    // Connect to FCM since connection may have failed when attempted before having a token.
    connectToFcm()
}

Answer 2

I was having the same problem, but could not figure out what was going on.

The didRegisterForRemoteNotificationsWithDeviceToken suggested by @Sam is called (almost) every time, so it is a good work around. BUT, it is NOT called the first time you open the app with the refreshed token.

So for this scenario you still need the:

func messaging(_ messaging: Messaging, didRefreshRegistrationToken fcmToken: String) {
    print("Refreshed Token: \(fcmToken)")
}

So if you only use the:

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    if let fcmToken = InstanceID.instanceID().token() {
        print("InstanceID token: \(fcmToken)")
    }
}

You will only get the "refreshed token" the second time the user opens the app.

I managed to force a refresh token by uninstalling the app and cleaning the Build Folder (Product > Clean Build Folder). Good for testing.

Ideally it could all be handled at messaging:didReceiveRegistrationToken delegate method, but I was not able to make it work. Another way to get notified for changes in the FCM token is to listen NSNotification named kFIRMessagingRegistrationTokenRefreshNotification as suggested in the documentation: https://firebase.google.com/docs/cloud-messaging/ios/client

Answer 3

Swift 4 + Firebase (5.3.0)

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    InstanceID.instanceID().instanceID(handler: { (result, error) in
        if let error = error {
            print("Error fetching remote instange ID: \(error)")
        } else if let result = result {
            print("Remote instance ID token: \(result.token)")
        }
    })
}

Answer 4

The tokenRefreshNotification function doesn't always get called when launching the app.

However, when placing the code inside the regular didRegisterForRemoteNotificationsWithDeviceToken delegate function, I can get the token every time:

func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
    if let refreshedToken = InstanceID.instanceID().token() {
        print("InstanceID token: \(refreshedToken)")
    }
}

(Swift 3 + Firebase 4.0.4)

Answer 5

First import the libraries like:

import FirebaseInstanceID
import FirebaseMessaging
import UserNotifications

set Delegate:MessagingDelegate, UNUserNotificationCenterDelegate

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate, MessagingDelegate, UNUserNotificationCenterDelegate {

Write this code on didFinishLaunching():

 func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    // Override point for customization after application launch.
    FirebaseApp.configure()
    Messaging.messaging().delegate = self

    //remote Notifications
    if #available(iOS 10.0, *) {
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { (isGranted, err) in
            if err != nil {
                //Something bad happend
            } else {
                UNUserNotificationCenter.current().delegate = self
                Messaging.messaging().delegate = self

                DispatchQueue.main.async {
                    UIApplication.shared.registerForRemoteNotifications()
                }
            }
        }
    } else {
        // Fallback on earlier versions
    }

    if #available(iOS 10, *) {
        UNUserNotificationCenter.current().requestAuthorization(options: [.badge,.sound,.alert], completionHandler: { (granted, error) in
            application.registerForRemoteNotifications()
        })
    }else{
        let notificationSettings = UIUserNotificationSettings(types: [.badge,.sound,.alert], categories: nil)
        UIApplication.shared.registerUserNotificationSettings(notificationSettings)
        UIApplication.shared.registerForRemoteNotifications()
    }

    return true
}

Write connectFCM method like this way:

func ConnectToFCM() {
    Messaging.messaging().shouldEstablishDirectChannel = true

    if let token = InstanceID.instanceID().token() {
        print("\n\n\n\n\n\n\n\n\n\n ====== TOKEN DCS: " + token)
    }

Also write delegate methods for registering and receiving push notification:

func messaging(_ messaging: Messaging, didRefreshRegistrationToken fcmToken: String) {
    print("\n\n\n\n\n ==== FCM Token:  ",fcmToken)
    HelperFunction.helper.storeInUserDefaultForKey(name: kFCMToken, val: fcmToken)
    ConnectToFCM()
}

@available(iOS 10.0, *)
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

   // UIApplication.shared.applicationIconBadgeNumber += 1

    NotificationCenter.default.post(name: NSNotification.Name(rawValue: "Barker"), object: nil)
}

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {

    print(userInfo)
}

func application(_ application: UIApplication, didReceiveRemoteNotification userInfo: [AnyHashable: Any],
                 fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {

    print(userInfo)

    completionHandler(UIBackgroundFetchResult.newData)
}

}

Now we can test it from firebase console.

100% working, easy and tested

Note: 1) Enable push notification from capability section of xcode.

2) check twice your both p12 certificates uploaded on firebase project setting.

3) Device token only can get from real device not a simulator.

Answer 6

Go with the second option, and this is going to seem really stupid/simple, but to fix that nil optional fatal error, just remove the force-unwrap at the end

Your code:
var token = FIRInstanceID.instanceID().token()!
Make it:
var token = FIRInstanceID.instanceID().token()

That will at least fix that nasty crash