iOS push notifications - how to deal with device ID?

Question

What is most commonly used strategy? I'm trying now to implement following:

On application start:

• Get previously saved device Id from some local storage
• Get device Id
• If changed, save new Id, send update to server

Is this right approach? What is the best way to store device Id locally?

Answer 1

Best practice is to send the push device token (not the same as the uniqueIdentifier mentioned by Serg Shiyan) to Apple every time the app starts. This will let Apple know your app is still active.

See registering for remote push notifications:

By requesting the device token and passing it to the provider every time your application launches, you help to ensure that the provider has the current token for the device.

from the Local and Push notifications Programming guide

In my experience there are a number of reasons why push tokens might be invalidated. These include app deinstalls and mixing apps with different certificates (dev, ad-hoc running against sandbox / live push servers). It will save you some debugging by sending the token on start each time as recommended.

So basically there is no reason to store the push token other than in memory while your app is running. You just request a new one (possibly the same one) the next time your app starts.