remote push Notification when app is in background swift 3

Question

I have an app that receives remote push notification. I have implemented didReceiveRemoteNotification in this way:

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


        print("PUSH NOTIFICATION is coming")

        let state: UIApplicationState = UIApplication.shared.applicationState
        let inBackground = state == .background
        let dizionario = userInfo["aps"]! as! NSDictionary
        let alert = dizionario["alert"]! as! String
        print(alert)


        if(!inBackground){

                print("APP IN FOREGROUND")
                //show alert view and the if user tap 'ok' show webview

             }
            else{

                print("APP IS BACKGROUND")
                //SHOW WEBVIEW

              }
           }

In both cases(when app is in foreground and background) I have to show webview that add like child to root view(tabbar controller) but if app is in foreground then I have to show , before , an alert view. My problem is that if app is in foreground I haven't problems , but if app is in background didReceiveRemoteNotification doesn't call(I don't see the print "PUSH NOTIFICATION is coming" ) and I don't understand why.

Can you help me?

N.B for testing I use APN Tester(https://itunes.apple.com/it/app/apn-tester-free/id626590577?mt=12) for send push notification

Solution

didReceiveRemoteNotification is meant to be used when the app is active.

When the app is in the background or inactive, you can activate it by pressing the action button on the remote notification. Implement userNotificationCenter(_:didReceive:withCompletionHandler:) in your app delegate.

Comments

[Paulw11]

Have you specified "Remote notifications" in your app's background mode capabilities? Also, when your app is in the background you cannot display a web view or otherwise force your app to the foreground.

[Gruntcakes]

There are two types of push, one which is delivered to the user always, and one which is delivered to the app without the user seeing it. If your app is in the background you can use this second type of push. However, as Paulw11 has pointed out, given your explanation of why you want to use it, it is pointless as there is no way you can force a background app to come into the foreground i.e. a background app cannot display any GUI (with the exception of posting a local notification).

[Paulw11]

That is the new iOS 10 method, but the method shown by the OP, while deprecated on iOS 10 is required for earlier versions of iOS and will still work on iOS 10.