Is There A Point In Collecting Registration Tokens When Using Only The Gcm Topics?

I'm currently implementing Google Cloud Messaging into my app. Basically my app has categories and I need my users to be notifed about recurring events in those categories. I deci

Solution 1:

As it isn't the best practice but technically there is no need to store tokens on your server if you just want to use topic messaging.

You should be aware of these points:

• You can't send a push notification to a specific user anymore.
• You have to handle onTokenRefresh() carefully and eachtime you get a new token register the user for all of the desired topics agian.
• As topic messaging is a new feature on GCM some of the users with old version of Google Play Services maybe unable to subscribe to topics. See this page.
• Each topic has a limit for maximum number of registered users (1 Million user per topic)