CODEWITHSUNDEEP
androidpush-notificationfirebase-cloud-messaging
Aourinmouche Soufiane
Aourinmouche Soufiane

Reputation: 137

When should we refresh android device token?

My app sends notifications using Firebase Cloud Messaging FCM. For every user, I'm storing the device token in database and I fetch it when I want to notify him. I'm using FirebaseMessagingService with the overridden method onNewToken that updates my database with new tokens. I suppose that this method is called every 1 hour to check token's update, but I was expecting it to be also called when the service is initialized for the first time (after installing and running the app on device). However this is not the case. To remedy this, I could call onNewToken each time the user log in But I would like to know if this is an acceptable way or there is a better one.

To avoid abuse, I leave here extra information on my case : I run my app on Android Studio emulator and I check the stored token in database, let's call it TOKEN-1. Now I install the app on my phone and I show the token with String token = FirebaseInstanceId.getInstance().getToken(); Toast.makeText(MainActivity.this, token, Toast.LENGTH_LONG).show(); The token is different that the first one TOKEN-1, and TOKEN-1 is still stored in my database. This means that I can receive notifications only on emulator and not my phone.

Sorry for my long text and looking forward to reading your suggestions.

Upvotes: 2

Views: 2844

Answers (1)

Frank van Puffelen
Frank van Puffelen

Reputation: 598765

The FCM SDK and server work together to manage the token in the background, and listening to onNewToken ensures that you get notified when the token changes. For this reason you should always be listening to onNewToken, and update it in your own database whenever it changes.

There is no guarantee that your FCM token will be refreshed every hour (or even ever) though, as you seem to expect. Given the 1 hour interval, you might be thinking of Firebase Authentication ID tokens, which are short-lived and are indeed refreshed every hour.

Finally: the token doesn't get refreshed when you attach a listener. In fact: if the token was already generated before you attach a listener, your listener won't be called. For this reason, you'll typically also want to grab the current token in your main activity when the app starts, and store it in the database at that point.

This last code is mostly necessary during development, as that's where you're most likely to have the scenario where the token gets generated when you don't have an onNewToken listener yet. So instead of putting code in the main activity, you can also uninstall/reinstall the app after adding your onNewToken listener, as FCM will generate a new token upon installing the app in that case - and thus call your onNewToken with this initial token.

Upvotes: 3

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