i have a firestore database firestore database structure
How do I write a cloud function to send a cloud message to all the app users when one of the fields in the firestore database is updated? in my case when the price of the price_change_pct field goes below the value -1 ?
You can refer to the link, where as stated:
You can invoke a Cloud Function from the Flutter app either through HTTP or a database trigger and let the Cloud Function do the work for
you. Inside the function use the Firebase Admin SDK and send messages as you wish.
In the Documentation, the whole description related to Firebase messaging for the multiple devices has been explained briefly.
You can also refer to the stackoverflow answer and case where the community resolved a similar issue.
Related
I have a Flutter app integrated with a Firebase Realtime Database.
I want a notification (actually an alarm kind of thing if possible), when an item (lets call it alarm) in the database is set to "true". I always see firebase_messaging plugin for notifications, but I am not sure if I'm supposed to use this plugin despite that my app doesn't have anything to do with messaging.
I am totally new to both Flutter and Firebase, can you tell me how to listen to the database even if the app is not running?
By the way, I am currently building the app for only Android, but I want to build it for IOS too in the future.
Thanks.
You can use/write firebase cloud fucntion. Using firebase cloud function you can watch any document/field and try to write trigger logic like if a field is set to true then this cloud function will throw an notification via firebase messaging.
https://firebase.flutter.dev/docs/functions/overview/
When the user is not actively using the app there is no reliable way to continue to listen to changes in the Firebase Realtime Database. To notify the user of changes to the database in that situation, you'll need to listen for those change on an environment that is always on, and then send a message to the user through Firebase Cloud Messaging.
One environment that is always in is Cloud Functions, which is also part of Firebase, and allows you to run small snippets of JavaScript code on Google's servers in response to things that happen in your Firebase project. The documentation of Cloud Functions for Firebase as example of how to notify the user when something interesting happens in the database:
Developers can use Cloud Functions to keep users engaged and up to date with relevant information about an app. Consider, for example, an app that allows users to follow one another's activities in the app. Each time a user adds themselves as a follower of another user, a write occurs in the Realtime Database. Then this write event could trigger a function to create Firebase Cloud Messaging (FCM) notifications to let the appropriate users know that they have gained new followers.
The function triggers on writes to the Realtime Database path where followers are stored.
The function composes a message to send via FCM.
FCM sends the notification message to the user's device.
To review working code, see Send FCM notifications.
I am using Firestore as a database for my flutter app. Some actions on my app lead to change/update in Firestore data.
I am using Flutter native notifications which are generated once a button is clicked. However, the data passed to the notification remains constant despite the data having been updated later in the Firestore.
I would like to implement a feature similar to the one present in sport apps where the live score is updated regularly in the notification.
How can I achieve that in my app? Do I have to use Firestore Cloud Messaging? Citing resources would be helpful.
What you want to achieve sounds like an ideal case for Firebase Cloud Messaging to be used. I recommend that you take a look at the FlutterFire documentation for Cloud Messaging both overview and usage, which should give you a good starting point.
Alternatively you can also use a Cloud Function as the host of FCM and only configure your app to receive messages, you can watch this video for insights on how to create the Cloud Function side.
I'm thinking about implementing Firebase Cloud Messaging without implementing a firebase database and it's unclear to me which features of FCM are supported without having a firebase database.
For instance, getting message delivery statistics (https://firebase.google.com/docs/cloud-messaging/understand-delivery) and sending notifications via the firebase console (https://firebase.google.com/docs/cloud-messaging/js/send-with-console). It doesn't explicitly say whether you need a firebase database in either of documents but I'd like to clear about that before implementing it.
So my question is, do you need a firebase database to send notifications via the firebase console or to view message delivery statistics? I know for the latter you need to implement google analytics. And also as a bonus, are there any firebase features that depend on having a firebase database?
Thank you
All FCM features are supported without having to use Realtime Database. They are completely separate products, and are only related as much as you want them to be in your app.
I started working with Firebase in order to simplify the use of Push Notifications of my app. Searching around the Docs I found the possibility to send a notification to a group of devices through a topic which the devices are subscribed to.
My doubt comes out here. When I subscribe the devices (using firebaseToken) to the topic I want to use, does this topic creates implicitly if it's not created?
If it doesn't, when and how can I create a topic to use it later?
I'm using Firebase Cloud Store an Firebase Messaging.
You don't need to create a topic in order to use topic messaging. It just works the way you expect as long as the server and clients all agree on the name of the topic.
Firebase Cloud Messaging isn't related to Cloud Firestore in any way, other than that they are both Firebase products and are seen together in documentation and the console.
In times when Parse.com was on they had a function that called a cloud function directly and returned whatever I wanted. So I could have all the server logic on the server, not in client code. Doe's Firebase has it as well? I can't find it - all I found are HTTP triggers, but it implies that it's not available through Javascript SDK. Am I missing something or do I have to use REST interface for that?
To run server-side code that is triggered by events in Firebase, you'd use Cloud Functions for Firebase. Currently these can trigger code through the Firebase Database updates, Authentication, Analytics, Cloud Storage and HTTP. The documentation I linked has all the details.
As Frank van Puffelen has explained you could use Functions, I'll like to add a couple of things.
You could also use the Firebase Database Admin SDK for the Database, this requires you have a server
Firebase Functions is a sort of big brother, constantly listening for whatever you want. Currently starting and deploying functions is fairly easy and fast, I love this how to video. Basically, you have to install the CLI and then using commands, create a project, write your js for Functions and for deploying those changes to Firebase Functions use the CLI again
Functions can listen more than what the Admin SDK can, the Admin SDK is for the Database while Functions is for, authentification, database, and cloud messaging. This means any user registration or deletion or any change in a node, can trigger further logic. This logic could include sending push notifications. There is a github repo where you can see a lot of examples, I made myself a small repo for the same purpose