iOS push notification willPresent notification delegate method is not calling when app is in foreground

Question

I have implemented the push notification in the app. I am getting callbacks on the following delegate method whenever the push comes.

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

I have implemented the following delegate method To show the push notification when the app is in the foreground.

func userNotificationCenter(_ center: UNUserNotificationCenter,
                                    willPresent notification: UNNotification,
                                    withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void)
    { 
       completionHandler([.alert, .badge, .sound])
    }

Unfortunately, it is not working every time. Irrespective of the app state I'm getting the callback on didReceiveRemoteNotification method. Is there any particular reason for this behavior? Am I missing something?

Thanks in advance

Answer 1

I think you have to use the userNotificationCenter with the "didReceive response" signature instead of the application(didReceiveRemoteNotification userInfo:..)

// MARK: Notification handling

// If the app is in the background
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
    let id = response.notification.request.identifier
    print("Received notification with ID = \(id)")

    completionHandler()
}

// If the app is in the foreground
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
    let id = notification.request.identifier
    print("Received notification with ID = \(id)")

    completionHandler([.sound, .alert])
}

Also have your AppDelegate be UNUserNotificationCenter delegate.

class AppDelegate: UIResponder, UIApplicationDelegate, UNUserNotificationCenterDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        UNUserNotificationCenter.current().delegate = self
    }
.
.
.
    }