iOS background fetch clears previous notifications

Question

It looks like no matter I return UIBackgroundFetchResultNewData or UIBackgroundFetchResultNoData from performFetchWithCompletionHandler, it clears all previous notifications (local or push) for my app. This is not acceptable for me.

Anyone knows how do I do fetch and not make previous notifications cleared (disappear)?

Answer 1

My guess here is that you had a background fetch that was setting your badge number to 0, if that ever happens all your notifications are cleared.

Answer 2

Source: Apple's AppDelegate API Reference

application(_:didReceiveRemoteNotification:fetchCompletionHandler:)

Tells the app that a remote notification arrived that indicates there is data to be fetched. Use this method to process incoming remote notifications for your app. Unlike the

application(_:didReceiveRemoteNotification:)

method, which is called only when your app is running in the foreground, the system calls this method when your app is running in the foreground or background. In addition, if you enabled the remote notifications background mode, the system launches your app (or wakes it from the suspended state) and puts it in the background state when a remote notification arrives. However, the system does not automatically launch your app if the user has force-quit it. In that situation, the user must relaunch your app or restart the device before the system attempts to launch your app automatically again. If the user opens your app from the system-displayed alert, the system may call this method again when your app is about to enter the foreground so that you can update your user interface and display information pertaining to the notification.

Note: You need to make sure that the app is checking for the state before settings the application's badge number to 0. Test the below cases:

• Application running, receives a notification

• Application terminated, receives a notification

• Launch app directly from app icon

• Launch app from notification received

Knowing the difference between the 3 approached below is essential in your use case.

1. Checking the notification object received in application(_:didReceiveRemoteNotification:)

2. Checking the notification object received in application(_:didReceiveRemoteNotification:fetchCompletionHandler:)

3. Checking the didFinishLaunchingWithOptions for UIApplicationLaunchOptionsRemoteNotificationKey