Is it possible to schedule a SILENT local notification in iOS?

Question

I am trying to schedule a notification locally as I don't have the necessary structure in the backend yet. The idea is that after a X period of time, certain conditions are validated; and if fulfilled, a regular local notification is triggered.

This could be easily achieved using a timer for instance, but some of this periods are long enough (1 hour, 24 hours) that this doesn't work.

This is how I end up thinking in the local notifications. I could schedule one with a firedate of +24hs. The thing is that I need this to be silent in order to validate the conditions.

From the configuring a local notification section here it seems that only remote notifications can be silent, but it doesn't really say it can't be done.

Also, I've found that it is possible to trigger a local notification with nothing but the badgeNumber, and it WILL change the badge. Though the callbacks in my AppDelegate are never called.

I've seen some people say it can't be done, but haven't found a real hard official evidence stating it. Anybody managed to do this? Or know for sure this is in fact impossible? Any advice will be of great help, thanks a lot in advance!

Answer 1

I tried and had the same experience as you - the callbacks are never called when my app is not in the foreground. This is by design. The Apple documentation states that the callback is only called when your app is in the foreground userNotificationCenter:willPresentNotification:withCompletionHandler:https://developer.apple.com/reference/usernotifications/unusernotificationcenterdelegate/1649518-usernotificationcenter?language=objc

The only callback method for receiving notifications when the app is not in the foreground is didReceiveRemoteNotification but unfortunately it is only for push notifications (silent or otherwise). https://developer.apple.com/reference/usernotifications/unusernotificationcenterdelegate/1649518-usernotificationcenter?language=objc