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Usage

As mentioned in How it works?, you will need to register a user using Firebase Authentication. If you are using Firebase Authentication as your auth provider you don't need to do anything except calling FirebaseChatCore.instance.createUserInFirestore after registration.

import 'package:flutter_chat_types/flutter_chat_types.dart' as types;import 'package:flutter_firebase_chat_core/flutter_firebase_chat_core.dart';
await FirebaseChatCore.instance.createUserInFirestore(  types.User(    firstName: 'John',    id: credential.user!.uid, // UID from Firebase Authentication    imageUrl: 'https://i.pravatar.cc/300',    lastName: 'Doe',  ),);

You can provide values like firstName, imageUrl and lastName if you're planning to have a screen with all users available for chat. The id is the only required field and you need to use the uid you get from the Firebase Authentication after you register a user. If you don't use Firebase for authentication, you can register a user using your custom JWT token, then call FirebaseChatCore.instance.createUserInFirestore as described above.

Aside from registration, you will need to log users in when appropriate, using available methods from Firebase Authentication, including the custom JWT token.

Firebase Chat with custom backend#

This wasn't verified on production, but if you have your backend and want to use Firebase only for the chat functionality, you can register/login users using custom JWT token as described above and save received uid to your users table. Then you can have a screen with all users from your users table where each of them will have an assigned uid that will be used to start a chat. Or maybe you will have a search mechanism implemented on your backend, or you don't show users at all, just a button to start a chat with a random person, you still have access to that uid.

Alternatively, you can use the FirebaseChatCore.instance.users() stream which will return all registered users with avatars and names.

import 'package:flutter/material.dart';import 'package:flutter_chat_types/flutter_chat_types.dart' as types;import 'package:flutter_firebase_chat_core/flutter_firebase_chat_core.dart';
class UsersPage extends StatelessWidget {  const UsersPage({Key? key}) : super(key: key);
  @override  Widget build(BuildContext context) {    return Scaffold(      body: StreamBuilder<List<types.User>>(        stream: FirebaseChatCore.instance.users(),        initialData: const [],        builder: (context, snapshot) {          // ...        },      ),    );  }}

Starting a chat#

When you have access to that uid or you have the whole User class from the FirebaseChatCore.instance.users() stream, you can call either createRoom or createGroupRoom. For the group, you will need to additionally provide a name and an optional image.

import 'package:flutter/material.dart';import 'package:flutter_chat_types/flutter_chat_types.dart' as types;import 'package:flutter_firebase_chat_core/flutter_firebase_chat_core.dart';
class UsersPage extends StatelessWidget {  const UsersPage({Key? key}) : super(key: key);
  // Create a user with an ID of UID if you don't use `FirebaseChatCore.instance.users()` stream  void _handlePressed(types.User otherUser, BuildContext context) async {    final room = await FirebaseChatCore.instance.createRoom(otherUser);
    // Navigate to the Chat screen  }
  @override  Widget build(BuildContext context) {    return Scaffold(      body: StreamBuilder<List<types.User>>(        stream: FirebaseChatCore.instance.users(),        initialData: const [],        builder: (context, snapshot) {          // ...        },      ),    );  }}

Rooms#

To render user's rooms you use the FirebaseChatCore.instance.rooms() stream. Room class will have the name and image URL taken either from provided ones for the group or set to the other person's image URL and name. See Security Rules for more info about rooms filtering.

import 'package:flutter/material.dart';import 'package:flutter_chat_types/flutter_chat_types.dart' as types;import 'package:flutter_firebase_chat_core/flutter_firebase_chat_core.dart';
class RoomsPage extends StatelessWidget {  const RoomsPage({Key? key}) : super(key: key);
  @override  Widget build(BuildContext context) {    return Scaffold(      body: StreamBuilder<List<types.Room>>(        stream: FirebaseChatCore.instance.rooms(),        initialData: const [],        builder: (context, snapshot) {          // ...        },      ),    );  }}

Messages#

FirebaseChatCore.instance.messages stream will give you access to all messages in the specified room. If you want to have dynamic updates for the room itself, you will need to wrap messages stream with a room stream. See the example.

import 'package:flutter/material.dart';import 'package:flutter_chat_types/flutter_chat_types.dart' as types;import 'package:flutter_firebase_chat_core/flutter_firebase_chat_core.dart';
class ChatPage extends StatelessWidget {  const ChatPage({Key? key}) : super(key: key);
  @override  Widget build(BuildContext context) {    return Scaffold(      body: StreamBuilder<List<types.Message>>(        initialData: const [],        stream: FirebaseChatCore.instance.messages(widget.room),        builder: (context, snapshot) {          // ...        },      ),    );  }}

If you use Flyer Chat UI you can just pass snapshot.data ?? [] to the messages parameter of the Chat widget. See the example.

Send a message#

To send a message use FirebaseChatCore.instance.sendMessage, it accepts 2 parameters:

  • Any partial message. Click here to learn more about the types or check the API reference. You provide a partial message because Firebase will set fields like authorId, createdAt and id automatically.
  • Room ID.

Update the message#

To update the message use FirebaseChatCore.instance.updateMessage, it accepts 2 parameters:

  • Any message. Click here to learn more about the types or check the API reference. Use a message you get from the FirebaseChatCore.instance.messages stream, update it and send as this parameter.
  • Room ID.

firebaseUser#

FirebaseChatCore.instance.firebaseUser is a shortcut you can use to see which user is currently logged in through Firebase Authentication. The returned type comes from the Firebase library and it is not the same User as from the flutter_chat_types package.

note

firebaseUser will not be updated dynamically, if you are looking for that feature, use FirebaseAuth.instance.authStateChanges() from the Authentication plugin.