My flow is:
At the login store FCM token in firestore DB and also subscribe to 2 topics for notification
On change/refresh of fcmToken : again store it in DB (replace old fcmToken and keep current) and subscribe again to those 2 topics.
My doubt is do i need to unsubscribe old FCM token from those 2 topics ?
The Firebase Cloud Messaging topic fan-out service, which handles the mapping from a topic to the associated FCM tokens, automatically detects invalid and expired tokens and removes them as needed. So while you can unsubscribe them yourself, it is not required to do so.
The approach FCM takes for this is similar to what you see in to this code sample from one of our repos. You won't need it when you only use topics, but if you ever decide to implement your own token registry you'll want to use that approach to prune that registry.
Related
I want to send push notifications by specifying device-token and also a specific Topic.
Is it possible to do this using Firebase admin-SDK? The documentation specifies Topics and device-token methods separately but no clear definition to use both methods together.
admin.messaging().sendToDevice(tokens, payload)
admin.messaging().sendToTopic("TOPIC", payload)
There is no API (neither in the Admin SDK, nor in the REST API that is uses under the hood) to send messages to both topics and a set of tokens with a single call.
The closest I can think of is to have those devices subscribe to a secondary token, and then using an OR condition to send to both topics.
Is there a way to unsubscribe all users from a topic in Firebase Cloud messaging without knowing the tokens? Basically, "delete" the topic?
It would be really really painful to do this manually since it should happen with a document change trigger, meaning the function would somehow have to know all the user tokens. So it's either a function/set of functions for "get all tokens for topic, then unsubscribe all of them", or "delete topic". Are there any solutions to this?
There is no API to unsubscribe all tokens from a specific topic. There also is no API to get a list of tokens for a topic. See How to get client FCM tokens from a FCM topic
Topics are automatically created and deleted by Firebase Cloud Messaging. A topic is created when you first subscribe a token to it, or send a message to it. And it's essentially deleted when you remove the last token from it.
I am new to firebase. I want to send notification to my list of followers(group of members like instagram).
I created a unique topic for each user and all the followers of a user will subscribe to the topic. when i send a notification to the topic, notification not delivered to all followers consistently.
When User clicks follow button i am subscribing to the topic by
FirebaseMessaging.getInstance().subscribeToTopic(FollowerUserID);
by clicking unfollow i am unsubscribing the topic
FirebaseMessaging.getInstance().unsubscribeFromTopic(FollowerUserID);
I have used Firebase cloud functions for pushing notification to the Topic.
If Firebase Token changed for a user whether we need subscribe the topic again?
I don't know how the subscribe/unsubscribe model works. will anyone explain how its works ?
kindly help me get out of this problem.
Suggest me the best way to send notifications to group of peoples(Followers).
First thing first.
If a firebase user token changes and that token was subscribed to a cloud messaging notification then he will no longer receive any notifications, also if he was subscribed to a topic and that topic changes he won't get any notifications from the new topic
For your business logic, I'd make a cloud messaging topic for each user and whenever someone follows that user I will subscribe that user token to the topic of the followed user.
say user X followed user Y, and user Z followed user X. both Y and Z will subscribe to topic X.
check this link
https://firebase.google.com/docs/cloud-messaging/admin/manage-topic-subscriptions
Firebase Cloud Messaging topics subscribe based on Instance ID, not FCM Token. An Instance ID uniquely identifies an app device instance and does not change unless the user uninstalls the app. If an app instance is subscribed to a topic, it will remain subscribed to it. While FCM Tokens periodically refresh, this does not affect topic subscriptions. There is no need to resubscribe users every time a token refreshes. See the guide for some useful information. You can also see the reference indicating how subscribeToTopic works with the Instance ID.
1 Are FCM token and Instance Id one and the same?
In my next questions, I suppose there aren't.
2. Is it possible to register an app instance ID twice to the same topic?
FCM token and Instance Id expire and are refresh.
3. Do we need to subscribe to a topic again after a token refresh?
I suppose we do.
4. Should we listen to a FCM token refresh or to an Instance Id refresh?
I am confused because the Firebase iOS API to register to a topic is:
[[FIRMessaging messaging] subscribeToTopic:#"news"]
It is not explicit which token is involved. My guess is that the internal logic uses the Instance Id because the server API endpoint is https://iid.googleapis.com/iid/v1/IID_TOKEN/rel/topics/TOPIC_NAME
However the Firebase documentation only mentions FCM token refresh and how to monitor them.
The InstanceID and the Token are different. See an explanation of the InstanceID in my answer here, and a general explanation for the token in my answer here.
Usually tho, the token (when printed) contains the InstanceID as well. It may be a format Google chose to make sure that the token is unique, or to connect it to a specific device. I can't say for sure.
There is no way that you can duplicate a subscription. Whenever a token is refreshed, the corresponding subscriptions are kept by the new token.
No. See #2.
It uses the token. The InstanceID is just the ID for the app instance. The token is what FCM needs to send the message.
I'm looking at implementing messaging between mobile and browser apps using Firebase cloud messaging and i have a few questions, that the docs don't seem to answer.
For being able to receive messages, you need a Registration Token (RT).
Messages can be send to a RT, to a topic or to a device group notification_key.The RT can also be used:
directly
to subscribe to a topic
to add to a device group
The RT can also expire/change.
In my app, I'm maintaining a list of RT per user. Now, when the RT changes:
Do I have to unsubscribe the old token and subscribe the new token to topics?
Do I have to remove the old token and add the new token to device groups?
Is it possible to get information about device groups/topics for a token?
Can I add a token to a device group more than once?
Can I subscribe a token to a topic more than once?
Will multiple subscriptions/additions of the same token result in receiving duplicate messages
Sorry, that's a lot of questions, but I guess, for somebody who has gone through this, it should be pie ;)
Do I have to unsubscribe the old token and subscribe the new token to topics?
AFAIK, you don't have to unsubscribe the old token, since it will be discarded by FCM itself. For the new token, yes, you'll have to subscribe it to the topic you need. The usual thing is done (in Android) by having subscribeToTopic() in onTokenRefreshed().
Do I have to remove the old token and add the new token to device groups?
Yes. You have to handle the mapping/relationships for Device Group Messaging. See my answer here. This is different from topics. The token will be invalidated, but will be kept as part of the list of registration tokens for the corresponding registration key.
It's why there's a possibility to receive a NotRegistred error on one of the tokens if you send to Device Group. :)
Is it possible to get information about device groups/topics for a token?
For Device Group Messaging (same with #2), the developer (you) have to manage these details yourself. For topics, you can use the InstanceID API. Specifically, set details parameter to true:
[optional] boolean details: set this query parameter to true to get available IID token details, including connection information and FCM or GCM topic subscription information (if any) for the device associated with this token. When not specified, defaults to false.
Can I add a token to a device group more than once?
Ahmm. Yes. Do you mean the same token? If so, I haven't tried it yet. Might as well do some checking on the client side before adding.
Can I subscribe a token to a topic more than once?
If you mean re-subscribing, then yes. If you mean duplicate request to subscribe, I think the result would still be a success. No changes in behavior though.
Will multiple subscriptions/additions of the same token result in receiving duplicate messages?
Tested it out. You won't receive duplicate messages for both duplicate topic subscriptions and adding the same token to a device group. It seems that FCM ignores the request to subscribe/add a Registration token if it's already subscribed/added to a device group.