CLLocationManager sometimes stops updating while app is in background

Question

I have an app which uses CLLocationManager to track the user's route, drawing dots along the path taken. The app runs in the background using Required background modes > App registers for location updates.

As I understand, anything that happens in the background needs to be called from locationManager:didUpdateToLocation:fromLocation as this is the method that gets called with each location update.

The problem I'm having is that sometimes this stops getting called. It seems to happen when the user's location does not change much within the space of maybe 15 minutes or so. As far as I can tell, calls to locationManager:didUpdateToLocation:fromLocation just stop, presumably to save the battery. Unfortunately, it doesn't resume again when you're back on the move.

I presume there's no way to override this behaviour, so I would like to use Notification Centre to inform the user that the app is no longer recording the route. The problem is, how can the app know that this has happened? If locationManager:didUpdateToLocation:fromLocation is not called, I can't fire my notification. If it is being called, the notification should not fire.

Is there some kind of system notification that says location updates will cease?

I'm finding it quite hard to debug this as I can't take my Mac everywhere when I'm out and about testing the location on the device (there's only so much you can do in the simulator). Any tips for debugging would also be much appreciated!

Answer 1

If you haven't found the answer, I think it is because of a new attribute added to CLLocationManager called pausesLocationUpdatesAutomatically. The attribute defaults to YES, and its behaviour is exactly as you describe. Try setting it to NO and I think it will fix your problem.

Answer 2

Starting in iOS9, make sure you're also setting this property on your location manager:

[locationManager setAllowsBackgroundLocationUpdates:YES]