Unsubscribe from Apple Push Notification service

Question

I'm developing an iOS app that enables the user to observe technical devices and be notified if there are problems.

What I know so far:

1. My app requests a token from the APNs.
2. My app sends this token to my server.
3. My server notifies the APNs in case of an event.
4. The APNs pushes a message onto the device.

What I want to know:

• I read the token may change, therefor I need to request it on every app launch. Is this true?
• If I get a new token from time to time I have to register at my server from time to time to make sure it uses the current token. Do I have to store and manually send the old token with the new one if the token changes to allow my server to delete the old one?
• How can I detect that a user removed the app to remove his device on the server?

Highest priority in my case is for the server to know which devices are registered with the service. Old devices (old tokens that is) need to be removed immediately.

Thanks for your help.

Answer 1

You should register for the remote notification on every app launch and send the token to your server.

To check if the user removed the app or disabled notifications you have to check the feedback service. Look for it on this page:

https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/BinaryProviderAPI.html#//apple_ref/doc/uid/TP40008194-CH13-SW1

Note: APNs monitors providers for their diligence in checking the feedback service and refraining from sending push notifications to nonexistent applications on devices.