Sending FCM messages to web apps through firebase cloud functions - javascript

Is it possible to send FCM notifications through Firebase Cloud Functions, when a Firestore data field changes, but for a website, not an app. There is lots of guidance out there for Android and iOS but nothing for simply web apps, outside of sending notifications from the Firebase Console).
I've been trying to find out how to trigger a notification from Cloud Functions but can't find anything useful.
As an example, my database has the following structure:
Collection: users
Documents: documents named using userID
Data Fields: Fields 1 through 5. Field 5 stores the FCM Token. Field 1 stores their status (online, offline, offline pending messages).
I would like to ensure that when Data Field 1 changes (to 'offline pending messages), that the relevant user gets notified (based on the Doc ID).
Edit: adding code below for reference
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.sendNotification = functions.database.ref('/users/{doc}/{Hears}')
.onUpdate(async (change, context) => {
const db = admin.firestore();
db.collection('users').doc(context.params.userId) // get userId
.get()
.then(doc => {
//this is intended to get the FCM token stored in the user's document
const fcmToken = doc.data().usrTkn;
// Notification details
const payload = {
notification: {
title: 'You have a new message.',
body: 'Open your app'
}
};
})
//This should send a notification to the user's device when web app is not in focus.
//FCM is set up in service worker
const response = await admin.messaging().sendToDevice(fcmToken, payload);
console.log(response);
});

Sending messages to a web app is no different from sending it to a native mobile app, so the sending part of guidance you've found is equally applicable. The Firebase documentation even contains an example of sending notifications on a Realtime Database trigger, and doing the same for Firestore would not be much different.
If you're having a specific problem sending messages, I recommend showing what you tried, and what isn't working about it.
Update: your code doesn't work (no matter what sort of device you send the notification to), because you're not handling the asynchronous nature of get() in your code.
The simplest way to fix that is to use await there too, just like you do when calling sendToDevice. So:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
exports.sendNotification = functions.database.ref('/users/{doc}/{Hears}')
.onUpdate(async (change, context) => {
const db = admin.firestore();
const doc = await db.collection('users').doc(context.params.userId).get();
const fcmToken = doc.data().usrTkn;
const payload = {
notification: {
title: 'You have a new message.',
body: 'Open your app'
}
};
const response = await admin.messaging().sendToDevice(fcmToken, payload);
console.log(response);
})
I highly recommend spending some time on learning about asynchronous calls, closures, async/await, and how to debug something like this by adding logging.

Related

Firebase Auth setCustomClaims() not working

I am facing a problem with setting custom claims for Firebase Authentication service's token. I am using Cloud function to set the custom claims for Hasura. The cloud function executes upon new user create event to set the custom claims. Here's my code running in cloud function
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
exports.processSignup = functions.auth.user().onCreate(user => {
// create custom claims for hasura
const hasuraClaims = {
"x-hasura-default-role": "user",
"x-hasura-allowed-roles": ["user"],
"x-hasura-user-id": user.uid
}
// attach claims to user auth object
return admin.auth().setCustomUserClaims(user.uid, hasuraClaims)
.then(_ => {
functions.logger.info('SUCCESS: Custom claims attached');
})
.catch(err => {
console.log('ERROR: ', err);
})
})
In my frontend web page, I am running the following code to get the idToken
// subscribe to user state change
firebase.auth().onAuthStateChanged(async user => {
console.log('Firebase auth state changed');
if (user) {
// User is signed in.
window.User = user;
let idToken = await user.getIdTokenResult();
console.log('idToken: ', idToken);
}
})
I don't know what I'm doing wrong, but the token doesn't contain the custom claims that I've set in my Cloud function processSignup(). I know that the function executed without error because I can check my function logs and find the info entry SUCCESS: Custom claims attached.
Can anyone please help me solve this problem?
Updating claims does not trigger an onAuthStateChanged (the auth state of being logged in or not has not changed, but the users' claims have) and tokens are minted and then used for ~1h.
You are calling getIdTokenResult but not forcing a refresh, try:
let idToken = await user.getIdTokenResult(true);
which will force a new token to be fetched from the server and will (hopefully) include your custom claims.

sending push notification using firebase functions every time a new child is added in firebase realtime database is not working

I am trying to send a push notification every time a child is created with no success.
I am creating a child with 2 token names with a question mark between them and trying to send to those tokens the notification.
to get the tokens from the phones I am using
new FirebaseMessaging().getToken() .
here is the firebase functions code
`
// // Create and Deploy Your First Cloud Functions
// // https://firebase.google.com/docs/functions/write-firebase-functions
//
// exports.helloWorld = functions.https.onRequest((request, response) => {
// response.send("Hello from Firebase!");
// });
// The Cloud Functions for Firebase SDK to create Cloud Functions and setup triggers.
const functions = require('firebase-functions');
// The Firebase Admin SDK to access Cloud Firestore.
const admin = require('firebase-admin');
admin.initializeApp();
exports.onNewMessage = functions.database.
ref('/messages/{pushId}')
.onCreate((snapShot,context)=>{
var str = snapShot.key();
var res = str.split("?");
// Notification details.
const payload = {
notification: {
title: 'title!',
body: `body!`,
click_action: 'FLUTTER_NOTIFICATION_CLICK'
}
};
// Send notifications to all tokens.
admin.messaging().sendToDevice(res[0], payload);
admin.messaging().sendToDevice(res[1], payload);
});` .
This may have many if-thens, but I will describe here the most common sources of errors
1) Did not grant permissions for notifications for iOS/Android platform. For Android it is fine, and relatively easy to receive notifications, but for iOS you need Developer account to do that (on December 2019 it was 99$ per year)
2) I would recommend using topic subscription instead of tokenization (i.e. .getToken()) as it removes burden of following every single sent message manually
For example:
final fbmsg = FirebaseMessaging();
fbmsg.requestNotificationPermissions();
fbmsg.configure(onMessage: (msg) {
print(msg);
return;
}, onLaunch: (msg) {
print(msg);
return;
}, onResume: (msg) {
print(msg);
return;
});
fbmsg.subscribeToTopic('chats');
You can configure onLaunch, onResume, and onMessage behaviors on your own demand
For (1) and (2), a great place to start is following documentation of firebase_messaging library
3) I am not sure about this, but I think a better way to use index.js file could be using the snapshot that you receive (or at least try console.log() of whatever you get to check validity). But if it works for you, just ignore this step :) Below I attach the code from my app with working notifications
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
exports.myFunction = functions.firestore
.document('chats/{message}')
.onCreate((snapshot, context) => {
return admin.messaging().sendToTopic('chats', {
notification: {
title: snapshot.data().username,
body: snapshot.data().text,
clickAction: 'FLUTTER_NOTIFICATION_CLICK'
},
});
});
4) I had hard time with establishing this Firebase Functions feature, also check installation steps for them as well
5) Check how you are trying to send the notification, first try to simulate it from the console, make sure that receiving part works, and then try to create an automated one
Hope it helped!

Firebase onWrite not triggered

I read all the answers I found about this but I still have some problems. Probably something with .ref(), but I can't see what I'm doing wrong. My cloud function is not triggered at all.
DB example:
business/{businessId}/reservations/{reservationId}
I want to trigger this function every time when a new reservation is created [a new document is created in reservation collection] (business/{businessId}/reservations/).
And then I want to sent a notification message, but that is another thing.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
exports.sendAdminNotification = functions.database
.ref("business/{businessId}/reservations")
.onWrite((event: any) => {
// It never comes here...
console.log('Here');
const payload = {
notification: {
title: 'New registration',
body: 'You have new registration!',
},
};
// You can ignore this part
admin
.messaging()
.sendToDevice('SomeToken', payload)
.catch(function (error: any) {
console.log('Notification sent failed:', error);
});
});
The fact that you're using the terms "document" and "collection" suggests that your database is Firestore. But what you've written here is a Realtime Database trigger. Realtime Database is a completely different database. Instead, you will need to write a Firestore trigger instead. They begin with functions.firestore.

How to send a fcm notification using javascript cloud functions in flutter?

I've created an app to test push notifications in a flutter app.
I am able to send a notification from the firebase messaging console and I can receive it as well in the foreground and background.
Once I've done this, I moved to the next step which is to send it automatically using the firebase cloud messaging service and I've used javascript and I've deployed function and it gets executed without any problem.
But the problem is that I can't receive a notification like this:-
but when I open my app since I've configured the firebase messaging inside initState(); I can see the notification and data get printed as well but I can't receive it like the photo above.
What should I do?
try to have a background handler or a top-level method as firebase messaging plugin's read me file says.
About my javascript index.js file:
It sends a notification for all the tokens in the pushTokens collection when a new document added to the posts collection and it does this but the problem is that I've mentioned above.
Index.js:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
var notificationMessageData;
exports.fcmTester = functions.firestore.document('posts/{postID}').onCreate((snapshot, context) => {
const notificationMessageData = snapshot.data();
return admin.firestore().collection('pushTokens').get()
.then(snapshot => {
var tokens = [];
if (snapshot.empty) {
console.log('No Devices');
throw new Error('No Devices');
} else {
for (var token of snapshot.docs) {
tokens.push(token.data().tokenID);
}
var payload = {
"notification": {
"title": "from" + notificationMessageData.writer,
"body": "from" + notificationMessageData.name,
"sound": "default"
},
"data": {
"sendername": notificationMessageData.writer,
"message": notificationMessageData.name
}
}
return admin.messaging().sendToDevice(tokens, payload)
}
})
.catch((err) => {
console.log(err);
return null;
})
});
Put your app in background and try sending notification again bcoz flutter firebase messaging plug-in will not create notification if you are using the app while the notification has been sent although you can see its data in but to generate notification you have to do it manually if user is currently using the app.
On the other cases plug-in will create notification like if app is terminated or its in background.

How to access multiple Realtime Database instances in Cloud Functions for Firebase

I'm using multiple databases in a Firebase project. Cloud functions for the main (default) database work great, however, I cannot make them work for a secondary database. For example I want to make a read request on a node with admin privileges:
//this works
admin.database().ref(nodePath).once('value')...
This works in the main database, however, if I want to execute the command on another database, it doesn't work:
//this doesn't work
admin.database(secondaryDatabaseUrl).ref(nodePath).once('value')...
Although the functions are deployed, I get an error on the console when trying to execute the cloud function.
Here's the code for the cloud function with an https trigger:
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
const secureCompare = require('secure-compare');
exports.testFunction= functions.https.onRequest((req, res) => {
const key = req.query.key;
// Exit if the keys don't match
if (!secureCompare(key, functions.config().cron.key)) {
console.error('keys do not match');
res.status(403).send('error1');
return;
}
//test read request
//the line below crashes the function
return admin.database('https://secondary_db_url.firebaseio.com').ref(`/testNode`).once('value').then(dataSnapshot=> {
console.log('value', dataSnapshot.val());
return;
}).catch(er => {
console.error('error', er);
res.status(403).send('error2');
});
});
Below is the error log in the Firebase console:
TypeError: ns.ensureApp(...).database is not a function
at FirebaseNamespace.fn (/user_code/node_modules/firebase-admin/lib/firebase-namespace.js:251:42)
at exports.testFunction.functions.https.onRequest (/user_code/index.js:16:16)
at cloudFunction (/user_code/node_modules/firebase-functions/lib/providers/https.js:26:41)
at /var/tmp/worker/worker.js:671:7
at /var/tmp/worker/worker.js:655:9
at _combinedTickCallback (internal/process/next_tick.js:73:7)
at process._tickDomainCallback (internal/process/next_tick.js:128:9)
If I don't specify the secondary database URL, the function will make the read request on my main database which works great:
//this works
return admin.database().ref(`/testNode`).once('value').then(dataSnapshot=> {
...
I'm using the latest SDK versions: "firebase-admin": "^5.5.1" and "firebase-functions": "^0.7.3"
So, how do I get an instance of a secondary database in cloud functions using admin privileges?
Here's how to access database by URL using Admin SDK:
let app = admin.app();
let ref = app.database('https://secondary_db_url.firebaseio.com').ref();
Here's an example from Admin SDK integration tests: https://github.com/firebase/firebase-admin-node/blob/master/test/integration/database.js#L52
With cloud functions > 1.1 now, here is the documentation link that saved my life on this issue.
https://firebase.google.com/docs/database/usage/sharding#connect_your_app_to_multiple_database_instances
So, it looks like this at the top of my my cloud function index.js :
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp();
const dev = admin.initializeApp({
databaseURL: "https://appdev.firebaseio.com"
}, 'dev');
const v2 = admin.initializeApp({
databaseURL: "https://appv2.firebaseio.com"
}, 'v2');
and then, in my clond functions functions code I can do :
//will change stuff on default database
admin.database().ref().child(`stuff/${stuffId}`).set(myStuff)
//will change stuff on my dev database
admin.database(dev).ref().child(`stuff/${stuffId}`).set(myStuff)
//will change stuff on my v2 database
admin.database(v2).ref().child(`stuff/${stuffId}`).set(myStuff)
So it looks like you are trying to access multiple databases using the javascript web client API. Passing the URL of the database to the API like this doesn't work with the Admin SDK:
admin.database('https://secondary_db_url.firebaseio.com').ref(`/testNode`)
Instead, you have to initialize a second app, give it a name, and pass that app around to the Admin SDK APIs. Here's a complete sample that writes the same data to two different database instances in the same project:
const functions = require('firebase-functions')
const admin = require('firebase-admin')
admin.initializeApp(functions.config().firebase)
const otherConfig = Object.assign({}, functions.config().firebase)
otherConfig.databaseURL = 'https://your-other-db.firebaseio.com/'
const otherApp = admin.initializeApp(otherConfig, 'otherAppName')
exports.foo = functions.https.onRequest((req, res) => {
const data = { foo: 'bar' }
const p1 = admin.database().ref('data').set(data)
const p2 = admin.database(otherApp).ref('data').set(data)
Promise.all([p1, p2]).then(() => {
res.send("OK")
})
.catch(error => {
res.status(500).send(error)
})
})
Updating this while on Firebase Functions v3.14.0. None of this answers worked for me so I implemented this solution
instance Registers a function that triggers on events from a specific Firebase Realtime Database instance
functions.database.instance('my-app-db-2').ref('/foo/bar')
Use the name of the database instance and it works, no need for the url. functions.database.ref used without instance watches the default instance for events.
So if both the answers doesn't work.
What happened with me is both the method worked without any error but second instance of database was not getting updated.
I updated npm and firebase CLI it worked.
Also #Dough Stevenson you Passing the URL of the database to the API like this **does** work with the Admin SDK
And this is a good blog from Firebase about the same
Firebase Blog : Easier scaling with multi-database support!

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