Firebase Cloud Messaging

Step 1. Firebase Cloud Messaging project setup

• Create a Firebase project;
• Register a new application in the project:

• Download GoogleService-Info.plist;

• In the project settings, go to Cloud Messaging — Apple app configuration;
• Add the required APNs Authentication Key data (create the key in advance on Apple Developer):

Specify the following data:

• upload the downloaded .p8 file
• specify the key ID
• specify the team ID

Step 2. Altcraft resource setup

• Specify messagingSenderId;
• Specify projectId;
• Upload the Firebase private key file (.json). The file is created in the Project settings — Service account section.

Step 3. Integrating Firebase Cloud Messaging into the app project

• Move the downloaded GoogleService-Info.plist file to the app folder (app);

• Add the Firebase package using Swift Package Manager — repository Firebase. The Firebase package version must be compatible with the XCODE version.

• General:

  • Make sure the FirebaseMessaging library is added to the app target's Frameworks, Libraries, and Embedded Content.

• Signing & Capabilities:

  • PushNotifications;

Option 1: FirebaseAppDelegateProxyEnabled — YES (the default for Firebase Messaging)

1. Add the MessagingDelegate protocol to AppDelegate:

   class AppDelegate: UIResponder, UIApplicationDelegate, MessagingDelegate {}

This lets you receive the callback with the current FCM token through the messaging(_:didReceiveRegistrationToken:) method.

2. Initialize Firebase in didFinishLaunchingWithOptions:

   FirebaseApp.configure()
   Messaging.messaging().delegate = self
   application.registerForRemoteNotifications()

3. Implement the delegate method to receive the token:

   func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
       guard let token = fcmToken else { return }
       print(" FCM Token: \(token)")
   }

Full example of initializing Firebase and receiving the FCM token

import SwiftUI
import FirebaseCore
import FirebaseMessaging
import Altcraft

@main
struct IOSQuickStartApp: App {
   @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate
   
   var body: some Scene {
       WindowGroup {
           ContentView()
       }
   }
}

class AppDelegate: UIResponder, UIApplicationDelegate, MessagingDelegate, UNUserNotificationCenterDelegate {
   func application(
       _ application: UIApplication,
       didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
       /// Initialize Firebase
       FirebaseApp.configure()
       /// Set the delegate
       Messaging.messaging().delegate = self
       application.registerForRemoteNotifications()

       return true
   }
   
   func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
       if let token = fcmToken {
          // FCM token
       }
   }
}

Option 2: FirebaseAppDelegateProxyEnabled - NO

1. In the app target settings:

   • Info:
     • Add the FirebaseAppDelegateProxyEnabled (Boolean) key with the value NO to the app's Info.

2. The MessagingDelegate protocol is not required in this case. With FirebaseAppDelegateProxyEnabled disabled, Firebase does not perform automatic swizzling of AppDelegate, so the SDK itself controls the setup and handling of APNs and FCM tokens. The MessagingDelegate delegate is not needed in this case.

3. Initialize Firebase in didFinishLaunchingWithOptions:

   func application(
       _ application: UIApplication,
       didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
       FirebaseApp.configure()
       return true
   }

4. Receive and save the APNs token in didRegisterForRemoteNotificationsWithDeviceToken:

class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {
    func application(
        _ application: UIApplication,
        didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
    ) -> Bool {
        FirebaseApp.configure()
        return true
    }
    
    func application(
        _ application: UIApplication,
        didRegisterForRemoteNotificationsWithDeviceToken apnsToken: Data
    ) {
        // Save the token for later use when requesting the FCM token
        setAPNsTokenInUserDefault(apnsToken)
    }
}

Step 4. Manually setting the APNs token in Firebase Messaging before requesting the FCM token

Example inside the SDK provider

import FirebaseMessaging
import Altcraft

class FCMProvider: FCMInterface {

    /// Retrieves the current FCM token
    func getToken(completion: @escaping (String?) -> Void) {

        /// The APNs token retrieved from UserDefaults
        let apnsToken = getAPNsTokenDataFromUserDefaults()

        /// Set the APNs token manually before requesting the FCM token
        Messaging.messaging().apnsToken = apnsToken

        /// Request the FCM token
        Messaging.messaging().token { token, error in
            if error != nil {
                completion(nil)
            } else {
                completion(token)
            }
        }
    }

    /// Deletes the current FCM token
    func deleteToken(completion: @escaping (Bool) -> Void) {
        Messaging.messaging().deleteToken { error in
            if error != nil {
                completion(false)
            } else {
                completion(true)
            }
        }
    }
}