[DOC NEEDED] - How to implement a custom notifications delegate on iOS?

Description of the problem:

First of all, I’m sorry if this shouldn’t be reported as bug report, but I need help with this matter as soon as possible.

The problem that I’m facing is related to having a custom notifications delegate on iOS. I have been having a look at Capacitor core and I have seen that there is a delegate set for UNUserNotificationCenter. However, this delegate implementation doesn’t fit me because my app business requirements need another one. How could I override this implementation? If I try to register another delegate in my application AppDelegate, which is versioned, it doesn’t work because Capacitor core registers its delegate later.

On the other hand, I does be able to do what I want on Android by registering a custom FirebaseMessagingService in AndroidManifest.xml. In addition, I can even call Capacitor Push Notifications plugin to avoid breaking its implementation.

public class MyAppFirebaseMessagingService extends FirebaseMessagingService {

    @Override
    public void onNewToken(String newToken) {
        super.onNewToken(newToken);
        PushNotifications.onNewToken(newToken);
    }

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
        PushNotifications.sendRemoteMessage(remoteMessage);
        // I can do whatever I want
    }

}

<service android:name="com.demo.myapp.services.MyAppFirebaseMessagingService" android:stopWithTask="false">
    <intent-filter android:priority="9999">
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

Affected platform

• Android
• iOS
• electron
• web

OS of the development machine

• Windows
• macOS
• linux

Other information:

Capacitor version: 1.0

node version: 11.4.0

npm version: 6.5.0

CocoaPods version: 1.7.1

[jcesarmobile]

Just did some testing and by doing this with a custom UNUserNotificationCenterDelegate in AppDelegate the Capacitor one keeps working as expected.

func userNotificationCenter(_ center: UNUserNotificationCenter,
                              didReceive response: UNNotificationResponse,
                              withCompletionHandler completionHandler: @escaping (() -> Void)) {
    // Do your custom handling here
    let capVC = self.window?.rootViewController as? CAPBridgeViewController
    capVC?.bridge?.notificationsDelegate.userNotificationCenter(center, didReceive: response, withCompletionHandler: completionHandler)
  }
    
  func userNotificationCenter(_ center: UNUserNotificationCenter,
                              willPresent notification: UNNotification,
                              withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
    // Do your custom handling here
    let capVC = self.window?.rootViewController as? CAPBridgeViewController
    capVC?.bridge?.notificationsDelegate.userNotificationCenter(center, willPresent: notification, withCompletionHandler: completionHandler)
  }

From custom plugins is even easier as they already have the bridge object and can skip the let capVC = self.window?.rootViewController as? CAPBridgeViewController part.

[rpanadero]

By the way, I have found out another issue related to the iOS notifications. The application is not notified by any Capacitor push notification callback when a notification is received while the application is in background. In addition, if the notification is “content-available” the application is not notified either in background or foreground.

In order to support this iOS feature it should be necessary to implement this method of AppDelegate:

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))completionHandler NS_AVAILABLE_IOS(7_0);