import UIKit
import UserNotifications
import FirebaseCore
import FirebaseMessaging
@main
class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate, MessagingDelegate {
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
FirebaseApp.configure()
UNUserNotificationCenter.current().delegate = self
Messaging.messaging().delegate = self
window = UIWindow(frame: UIScreen.main.bounds)
window?.rootViewController = PushNotificationViewController()
window?.makeKeyAndVisible()
return true
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let tokenParts = deviceToken.map { data in String(format: "%02hhx", data) }
let token = tokenParts.joined()
print("APNs device token: \(token)")
NotificationCenter.default.post(name: .didReceiveDeviceToken, object: token)
}
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
print("Failed to register: \(error)")
NotificationCenter.default.post(name: .didFailToRegister, object: error.localizedDescription)
}
// MARK: UNUserNotificationCenterDelegate
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification) async -> UNNotificationPresentationOptions {
return [.banner, .sound]
}
// MARK: MessagingDelegate
func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
guard let fcmToken = fcmToken else { return }
print("FCM token: \(fcmToken)")
NotificationCenter.default.post(name: .didReceiveFCMToken, object: fcmToken)
}
}
extension Notification.Name {
static let didReceiveDeviceToken = Notification.Name("didReceiveDeviceToken")
static let didFailToRegister = Notification.Name("didFailToRegister")
static let didReceiveFCMToken = Notification.Name("didReceiveFCMToken")
}
class PushNotificationViewController: UIViewController {
private let statusLabel = UILabel()
private let tokenLabel = UILabel()
private let registerButton = UIButton(type: .system)
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .systemBackground
setupUI()
addObservers()
}
private func setupUI() {
statusLabel.text = "Status: Not Registered"
statusLabel.translatesAutoresizingMaskIntoConstraints = false
tokenLabel.numberOfLines = 0
tokenLabel.translatesAutoresizingMaskIntoConstraints = false
registerButton.setTitle("Register for Notifications", for: .normal)
registerButton.translatesAutoresizingMaskIntoConstraints = false
registerButton.addTarget(self, action: #selector(registerTapped), for: .touchUpInside)
view.addSubview(statusLabel)
view.addSubview(tokenLabel)
view.addSubview(registerButton)
NSLayoutConstraint.activate([
statusLabel.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 40),
statusLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor),
tokenLabel.topAnchor.constraint(equalTo: statusLabel.bottomAnchor, constant: 20),
tokenLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
tokenLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20),
registerButton.topAnchor.constraint(equalTo: tokenLabel.bottomAnchor, constant: 40),
registerButton.centerXAnchor.constraint(equalTo: view.centerXAnchor)
])
}
private func addObservers() {
NotificationCenter.default.addObserver(self, selector: #selector(didReceiveDeviceToken(_:)), name: .didReceiveDeviceToken, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(didFailToRegister(_:)), name: .didFailToRegister, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(didReceiveFCMToken(_:)), name: .didReceiveFCMToken, object: nil)
}
@objc private func registerTapped() {
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { granted, error in
DispatchQueue.main.async {
if let error = error {
self.statusLabel.text = "Status: Permission Error"
self.tokenLabel.text = error.localizedDescription
return
}
if granted {
self.statusLabel.text = "Status: Permission Granted"
UIApplication.shared.registerForRemoteNotifications()
} else {
self.statusLabel.text = "Status: Permission Denied"
self.tokenLabel.text = ""
}
}
}
}
@objc private func didReceiveDeviceToken(_ notification: Notification) {
if let token = notification.object as? String {
DispatchQueue.main.async {
self.statusLabel.text = "Status: Registered with APNs"
self.tokenLabel.text = "Device Token:\n\(token)"
}
}
}
@objc private func didFailToRegister(_ notification: Notification) {
if let errorMessage = notification.object as? String {
DispatchQueue.main.async {
self.statusLabel.text = "Status: Registration Failed"
self.tokenLabel.text = errorMessage
}
}
}
@objc private func didReceiveFCMToken(_ notification: Notification) {
if let fcmToken = notification.object as? String {
DispatchQueue.main.async {
self.statusLabel.text = "Status: Registered with FCM"
self.tokenLabel.text = "FCM Token:\n\(fcmToken)"
}
}
}
deinit {
NotificationCenter.default.removeObserver(self)
}
}This solution sets up push notifications for an iOS app using both APNs and Firebase Cloud Messaging (FCM). The AppDelegate initializes Firebase and sets itself as the delegate for notification center and messaging. It handles device token registration and errors, posting notifications to update the UI.
The PushNotificationViewController shows the registration status and token. When the user taps the register button, the app requests notification permission. If granted, it registers for remote notifications to get the APNs device token. The app listens for notifications about device token and FCM token updates and displays them on screen.
This approach keeps UI and notification logic separated and uses NotificationCenter to communicate between AppDelegate and the view controller. It also handles permission denial and errors gracefully, updating the status label accordingly.
