Send Firebase Cloud Messaging notification to users by user property - firebase

I'm trying to send out an FCM message to a specific set of users (or really, a single user) based on a specific user property but looking through the FCM HTTP API I can't seem to find a way to do that. I can send to users via topics, registration tokens, and device group notification keys, but I don't have any of that infrastructure set up in the near term. I know this functionality exists as you can send such a message via the UI, but I'm not seeing how to do it in the API documentation as yet.

There is currently no parameter that you could use to specify a user property (or even for user segments) that will serve as a target for the FCM API to send the message to.
As you've already searched, the only targets possible are single/multiple registration tokens (to and registration_ids), topics, conditions, and device groups (notification_key).
The option you're looking for is currently only available when using the Notifications Console.

Related

Swift - FireStore/FCM (Firebase Cloud Messaging)

I've incorporated Firebase Cloud Messaging into my app. After messing around, I kind of understood the premise of how it operates. So, as a result, I structured my code so that when users sign up the FCM token is stored. After creating two accounts, I realise both FCM tokens for the user were the same.
Looked online and sorted this issue, and now I can refresh the token on launch, and still append the new FCM token when users initially sign up.
So now, I ask the question - Users are created with a fcmToken field (which I can refer to in my code), however, due to the fact a new token is generated on launch each time does this render the token(s) stored for each user useless? Or can I still push to the specific user using the fcmToken?
I've looked online, but can't seem to find an answer.
FCM tokens don't uniquely identify an individual end user. They identify a specific installation of an app on a specific device. When sending with that token, it doesn't matter who is signed in to the app (or if anyone is signed in at all) - the app will still receive it and need to figure out what to do with it. It's up to you to decide what to do with that message, given the sign-in state of the user. If you expect that your app could have multiple users sharing a single app on a single device, then you will probably want to send something in the payload to determine who that message was intended for, if necessary.
#doug great answer, but there's a common implementation problem when people share a device, so please add a warning, something like: often only the last logged in user should receive push notifications, otherwise he could see messages from the person who was logged in before. your backend should not only store all the devices a user is logged in, but also for each device who the last active user is and check this upon sending a push. the question whether you receive push or not when logged out is a common topic, too.

Is there a way to send with FCM a push notification directly to a specific device?

I am doing an application in health in Nativescript and using https://github.com/EddyVerbruggen/nativescript-plugin-firebase
where I need to send a specific user a notification to alert him about something.
I have seen that to send to a specific device, the registration token can be used but is there any other way?
PS : when the user log in, I have an internal id that can be used to identify the user.
There is no other way to securely target an individual device. The registration token is the way the FCM identifies the device.
If you would like a non-secure way of delivering the message, you could try to use a uniquely named topic, but be aware that any device attached to your project will be able to listen to every topic if they just know the name.

When and what Old FCM Tokens do I need to delete from my backend?

The way I understand Firebase Cloud Messaging at the moment, I will want to save all FCM tokens a user might have across devices to my backend and send a notification to all of these tokens at once when I want to notify that user about something.
Multiple tokens
Until this point, I assumed that each device only has one active token, however, reading this section of the documentation:
To enable this feature, make sure you have each sender's sender ID. When requesting registration, the client app fetches the token multiple times, each time with a different sender ID in audience field, using the token retrieval method for the given platform
Does this mean that I might need to target multiple active tokens per device?
Deletion
And now coming to the really important question. A simple solution to the above problem would be to simply store every token I ever retrieve in the backend and thus ensuring that my user will always receive the message.
However, what do I do if the user signs out of my app using Firebase Authentication, i.e. a different account is used in the same app on the same device?
I assume that the tokens I sent to my backend for this device will still be active - so now this user will receive notifications from another account because that account was signed in on the device previously.
I do have access to the current FCM token and I could delete that from my backend before signing out the old user, but considering the "Multiple tokens" section: how do I make sure that I can delete all FCM tokens of the old user from my backend?
Uniqueness
Additionally, assuming that old tokens are just dead for the device (will not trigger notifications anymore) when new ones are generated, can I be sure that this token will never be assigned to another device in the future?
TL;DR
How can I make sure that I have the correct FCM token(s) for my user stored in my backend and more importantly: how can I ensure that no tokens of other users are saved for some user in my backend?
I read through:
https://stackoverflow.com/a/40158260/6509751
However, I still do not know how to deal with multiple tokens.
Does this mean that I might need to target multiple active tokens per device?
An application has a single active token for each sender ID. It's fairly uncommon to have multiple sender ID, and you'd usually know if if you do. If you're sending from a single back-end, there's usually no need for having multiple sender IDs.

How to send a push notification from the Firebase console to a specific GCM/FCM device token ID

In Urban Airship, when I am composing a notification, I can target specific users by searching for a Urban Airship channel_id (device ID):
I sent from Urban Airship the push notification that I am showing above, and I received it successfully. Now I want to do the same thing, send a push notification to a specific device, but now using the Firebase console. The problem is that in Firebase, in the step where I need to specify the target, it only allows me to choose User segment or topic. I was expecting to see a third option: Target specific users (for sending notifications to one or many specific GCM/FCM device token IDs. So my alternative is to add a GCM/FCM device token ID to a topic and then send the push notification to that topic, which is something that I have successfully done before. Nonetheless, that would be a workaround and not the way I would prefer to do this. Is it possible to send push notifications to specific users (by defining the target GCM/FCM device token IDs) from the Firebase console? Thank you.
UPDATE 1: See how the Firebase console (https://console.firebase.google.com/) only shows User segment and Topic as the Target:
First Step:
Second Step:
Third Step:
By design, the notification feature in the console is for sending out broadcast-type events. Sending user-specific alerts would be more of a programmatic operation done through the API.
For sending test messages, there is a console tool for this, explained here.
Note that it is possible to send a notification to one device by subscribing a device to any topic and sending the notification to that topic in the console (keep in mind topics are public and you can't prevent users from signing up to them; fine for testing most likely).
Another alternative is to send a message via HTTP or curl. Perhaps the best resource for this is the quickstart/messaging example.

Dynamic Push Notifications

I know that Firebase has recently added support for Push Notifications and while this is a great thing, I only seem to be able to send push notifications manually via the Notifications Panel.
What I'd like to do is to send push notifications within a user scope...Let me explain that. Each User in my App has an account and then each user can join a group. Within this group the user can perform tasks and has a list of chores to do. Now when certain tasks are due for example I want to remind the user of doing it with a push notification. For 1-10 I might be able to pull this off manually, but is there a way to dynamically based on the data in the Database send out Push Notifications?
I know that certain Push Notifications can be created using the Analytics tool such as "Hey you have not visited for 3 days, please come back whatever"... but I'd like to register push notifications such as "I just created a task, this task needs to be done within 3 days. Remind me in 3 days if the task is still not done".
Is this possible with Firebase or do I need to have my own server connecting to Firebase and handling those events?
-xCoder
You need to implement FCM in your client and in a server. Let me put this straight:
First, you need that your client, or app, to register into FCM and get a FCM token that will be used to identify that device uniquely.
Then, store that token wherever you like. It can be into firebase database or other server you may like. I recommend you to store it into firebase if you are using it as a database for your users; that's my case.
Also, you need to implement a http or xmpp server in order to send FCM messages to your registered devices containing the data you are interested in. For example, you can implement a Google App Engine endpoint (can be done with Android Studio and Java) that is quite simple or a NodeJS module, depending on your preferred language.
If you are using Firebase as database you can connect from your server with the appropriate SDK and get the FCM tokens you want from your users, and then send the message to those with data. Don't forget to secure your serve.
The way you implement your server algorithm to send FCM messages depends on your app purposes.
Hope it is clear enough for you. Also you can find all the documentation with a short video that explains the general structure here: https://firebase.google.com/docs/cloud-messaging
You can use cloud functions to trigger on any create, update or delete operation in your database and in the trigger event, you can choose to send in FCM push notifications to the devices of your choice.
Here is the documentation regarding the use and structure of a cloud function: https://firebase.google.com/docs/firestore/extend-with-functions
Hope this helps!

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