Push Notification Device Token

Question

I have a live app. in apple store that implements a push notification procedure. As known I communicate with my server to send and save device tokens.

My server is receiving device tokens correctly for some devices(Requests) and also receives null values for some other devices.

How is that could be possible in any case?!

Answer 1

Then you have a bug in your code, the device never generates a null token, or you have failed to implement the following delegate:

- (void)application:(UIApplication *)app didFailToRegisterForRemoteNotificationsWithError:(NSError *)err

If this delegate gets called then you could/should implement a retry algorithm that retries to re-register for the APN token a few times.