iOS Push Notifications - device token management

Question

I am adding Push Notifications to my app and I know I need to store the device tokens in my database so that I can send push notifications to specific devices (or all devices).

My question is what is the best practice for maintenance of these device tokens? I can store all device tokens as they are received, but how can I detect and remove old device tokens that are no longer valid? I assume a device token can become invalid if user deletes the app, or if user turns off notifications for the app.

Update - Having a user authentication and linking it to the device token (and updating based on login/logout) makes sense. But what about if the user deletes the app? there is no logout, how do you remove the device token then?

Answer 1

The Apple feedback service is no longer used. Instead we have to look for a response status of 401 from the apple push notification service to determine that a token is invalid.

To test this in a development environment. Use the trick below (it says it's for feedback service, but should work with the new status code from APNS as well)

How to test Apple Push Notifications Feedback Service?

Answer 2

Your app server won't know if a particular app has been forcefully deleted & your server would still have let's say token T1 mapped to deleted app/device let's say A1. Now, it may be possible that another valid user (A2) comes up with same device token T1. You just need to make sure that at any point of time one device token (i.e. T1) is mapped to only one device (the device which has provided the T1 latest). All other older device token mappings i.e. A1-T1 shall be deleted at this point else A2 might receive A1's notifications.

Answer 3

Use the APNS feedback service, to find the device tokens that belonged to an app that was uninstalled. See this apple documentation

If you are using something like Amazon SNS for push notifications, you can use their API to get list of disabled arns and remove the corresponding device tokens from your database.

Answer 4

As you said in your last statement I assume a device token can become invalid if user deletes the app, or if user turns off notifications for the app.

General scenario is when user again login to the app or register to the app you need to again take the device token from the user and need to store it in your database

Suppose I had one app and again I install only that at that time whenever I login again to the app at that time the api must having parameter for deviceID so whenever api call happen for login at that time new device token take place in your database by just replacing the old one. Same thing will happen for new register with that app.

Hope above description help you. :)

Answer 5

Make an webservice which stores user's device token in database for particular user. Call this webservice only if user is logged in or you have identify user as per your requirement. You need to call this webservice when device successfully register for notification and if user is not identify (i.e. not logged-in) then call this service after login api.

Also pass device token when in login and register API if you have according to your flow and replace device token for particular user.

And when user logout just unregister for notification