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My problem is: I just can't make silent notifications work when a user has force-quit(swiped away) the app!

I guess the following is a fact: A silent push (with content-available:1) will NOT trigger application(_:didReceiveRemoteNotification:fetchCompletionHandler:) nor any other method (it will NOT launch the app) if the application was force-quit (swiped away) by the user! Can anyone prove this wrong?

I have made sure I've enabled Background Mode: Remote Notifications.

But what if non-silent notifications don't work for me? I need silent ones, I need to be able to run some checks before I show it! What If I want to check if the right user is logged on to my application after I receive a notification from remote server? (since I can't guarantee that when he logged out he successfully let the server know about it, so I assume the server doesn't know for sure)

What would be the right approach to take in my situation?

There are many questions about similar things, but not many people involved, I wonder why? I don't believe that I have such a rare case. Maybe my basic approach to solving this kind of problem is wrong? It doesn't seem to be a problem on Android platform at all!

I am using FCM as central point of sending out notifications, so if you say that PushKit can solve my problems, too bad that FCM doesn't support VoIP certificates. But, I wonder, can PushKit really solve this? Or Apple just designed it this way that when a user force-quit an app, it means that this app must shut up altogether with its ability to push remote notifications?!

I don't consider this a duplicate of Firebase silent notification does not start up a closed iOS app because what I am asking here is what would be the solution if you want to check if the user to whom the notification is addressed for corresponds to the user logged in to the application? It can be considered duplicate if it turns out that there is absolutely no solution for this on iOS platform.

Mikser
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  • Possible duplicate of [Firebase silent notification does not start up a closed iOS app](https://stackoverflow.com/questions/50241353/firebase-silent-notification-does-not-start-up-a-closed-ios-app) – mfaani Apr 04 '19 at 18:50
  • Regardless of this question being a duplicate, it's always best to link questions you've seen. Can you make an edit and link to them? – mfaani Apr 04 '19 at 18:57

2 Answers2

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You ask:

Or [has] Apple just designed it this way that when a user force-quit an app, it means that this app must shut up altogether with its ability to push remote notifications?

Yes, this is how it is designed. App Programming Guide for iOS: Understanding When Your App Gets Launched into the Background says:

In most cases, the system does not relaunch apps after they are force quit by the user. One exception is location apps, which in iOS 8 and later are relaunched after being force quit by the user. In other cases, though, the user must launch the app explicitly or reboot the device before the app can be launched automatically into the background by the system. When password protection is enabled on the device, the system does not launch an app in the background before the user first unlocks the device.

Rob
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  • Thank you for this reference to the official documentation, it will help me prove a strong case to my client why such thing is not possible on iOS. However, I just want to see if somebody may come up with some ideas for my "user logged out offline" case. – Mikser Apr 05 '19 at 09:21
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Is not possible. when the app is in background or suspended modes, you will have 30 sec to do some stuff. But if user kill app manually func didReceiveRemoteNotification will never called.

Upd:

When an iOS device receives a silent notification, the system wakes your app in the background and calls the application(_:didReceiveRemoteNotification:fetchCompletionHandler:) method of its app delegate. Your app has 30 seconds of wall-clock time to perform any tasks and call the provided completion handler. For more information, see Handling Notifications and Notification-Related Actions.

Vadim Kozak
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    but question about silent push notification and background task – Vadim Kozak Apr 04 '19 at 19:22
  • IIRC if it's suspended then its hibernated and you can't do anything. You have 0 seconds to do stuff.If it's backgrounded then you have either 5 seconds till it calls `AppWillTerminate` or 180 seconds if you have registered a background task. After 180 seconds app will get terminated – mfaani Apr 04 '19 at 19:23