Negation in condition while sending FCM message

Question

I am subscribing to a topic which is my application version in Android.

FirebaseMessaging.getInstance().subscribeToTopic(APP_VERSION);

Now every time I launch an update, I have to unsubscribe to an old version and subscribe to a new version so if I send an update notification only old users will get it. Instead, it would be great if I just negate a version.

"condition": "!'2.1.1' in topics",

Is something like this exists in FCM?

Answer 1

It looks like Firebase supports this now! Firebase send-message

You can include up to five topics in your conditional expression, and parentheses are supported. Supported operators: &&, ||, !. Note the usage for !:

!('TopicA' in topics)

With this expression, any app instances that are not subscribed to TopicA, including app instances that are not subscribed to any topic, receive the message.