How to retrieve all user tokens and send FCM to all

Question

I am trying to send a FCM to multiple users at a time. I can't seem to find a clear answer other than using a topic but i have several conditions which make this quite difficult on my side. Is it at all possible to extract all tokens from a particular document (similar to setting it up as a topic but based on my logic) and pass that array to the Cloud function?

My current code is as follows and it works for a single user (i am only posting the part where the token is extracted):

 return admin.firestore().doc('Seller_tokens/tokens/' + brand + '/wc').get().then(usertokensdoc =>{

             const sellertokenID = usertokensdoc.get("dXufWMvOTLXUOyj8XNv9NFmsQ4x1");

        const payload = {

            data:{
                title:'FCM - Test',
                content: 'FCM - This is a test message,

            },
            token: sellertokenID
        };

for the line:

const sellertokenID = usertokensdoc.get("dXufWMvOTLXUOyj8XNv9NFmsQ4x1");

I do not want to specify a single userid, where the 'userid' is the field in the document . And hence I would like to pass an array, if possible.

score 1 · Accepted Answer · edited Jun 20 '20 at 09:12

1

As you mentioned and as clarified in the official documentation Send messages to multiple devices, there are only two ways of sending messages to multiple tokens:

Firebase Cloud Messaging provides these two ways to target a message to multiple devices:

Topic messaging, which allows you to send a message to multiple devices that have opted in to a particular topic.

Device group messaging, which allows you to send a message to multiple devices that belong to a group you define.

In addition to this, as mentioned in this other question here, there is no API for you to get all tokens at once, so, you will need to get the individually for usage.

So, to summarize, there is not an automatic way of getting the tokens, but once you get them, I believe using the Device Messaging way would be better for you, since you can define specific groups to receive the FCM, per tokens that you retrieved.

Let me know if the information helped you!

edited Jun 20 '20 at 09:12

Community

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answered Apr 06 '20 at 07:01

gso_gabriel

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@gso-gabriel, I gave it some thought today and I think topics would be the best way to go. Will be giving it a try tonight. My only hope is that the conditions are not too complicated to replicate on cloud functions – Waseem Ahmed Apr 06 '20 at 17:44
Sure, I understand @WaseemAhmed and I hope everything goes smoothly for your development! :) – gso_gabriel Apr 07 '20 at 07:31
Just as feedback. Topic works amazingly. Had stage fright wanting to try it out but glad I did. – Waseem Ahmed Apr 08 '20 at 10:55

score 0 · Answer 2 · answered Apr 06 '20 at 07:53

you can retrieve the token documents based on your conditions in cloud function. loop through them, create an array of tokens and pass them to Firebase messaging as below admin.messaging.sendToDevice(tokens, payload). below url has a very good example.

FCM - Cloud Functions Example

How to retrieve all user tokens and send FCM to all

2 Answers2