Firechat

This is a complete Firebase chat package that has the following functions;

• 1:1 chat with same room
• 1:1 chat with new room
• Multi user chat with same room
• Multi user chat with new room
• Room information (like title) change.
• User invitation
• Kicking out a user
• Block a user
• Set a user as admin
• When admin leave the room, one of other user automatically becomes admin
• Listening changes of room list and showing new messages.
• Room password lock

Reference

• Most of the code is coming from FireFlutter.
• See the test code of FireFlutter.

TODOs

• Hide keypad automatically when user scroll the keypad only if the keypad is empty.

Overview

• Firechat does not support for file uploading since every app has different backends.
  • But it provides an interface for uploading photo and it should be very simple.

Resources

• Most of the code is coming from FireFlutter. It's worthy to check out FireFlutter README file.

Installation

Packages

• crypto is for encrypting user id list for a room id.

Firebase Auth

• User must login Firebase before using any of firechat code.

Global Rooms and User Rooms

• Global rooms are the room information documents that are saved under /chat/global-rooms/list collection.

• User rooms are the documents that has a room information for a single user.

• The differnces of global and user rooms are;

  • A global room has room informations like admins, password(to enter the room), room title, blocked user list, and more of the room itself.
  • A user room has information of the relation between the user and the room. Like no of new messages, last message of the room, etc.

Logic of Chat Room Create

• Create global room
• Send welcome messages to users (by creating user's room) in the global room.

Security Rules

• It's in firebase/firestore.rules

Test on Security Rules

• First setup Firebase project.

• Then, install Firebase tools and login. % npm install -g firebase-tools

• Then, log into Firebase % firebase login

• Then, install npm for testing.

% cd firebase
% npm init -y
% npm i -D @firebase/rules-unit-testing
% npm i -D firebase-admin
% npm i -D mocha

• Then, run Firestore emualtor

firebase emulators:start --only firestore   ; run firebase emulator

• Then, edit MY_PROJECT_ID with your Firebase project ID in chat.js.

• Then, run the test

./node_modules/.bin/mocha tests/chat.js

Developer Guideline

Global varaibles

• You may declare short helper tools like below.

room() {
  return ChatRoom.instance;
}
roomList() {
  return ChatRoomList.instance;
}

room().listen(() { ... });

Tests

• Read the comments on top of chat.test.dart to know how to run test code.
• Run the test code like below

import 'package:firechat/chat.test.dart';
a.firebaseInitialized.listen((ready) { // when firebase initialized,
  if (ready == false) return;
  FireChatTest().roomCreateTest(); // call test.
});

Known Issues

git error

fatal: filename in tree entry contains backslash: 'build\ios'

solution

git config --global core.protectNTFS false

Known Problems

• You may see permission error when user logs out and logs into another accounts. And simply ignore that error.

• When user scrolls up the chat room screen, the app will fetch next(previous) bunch of messages and it leads a sundden insertion of messages into chat room message list. And that causes the scroll position change a bit. And we accept it as a normal action.

Push notification

• The code below opens the chat room.
  • When the app is terminated, and there is a chat message arrived as a push notification. And when user tap on it, the app will boot and wait for the user login to firebase and opens the chat room.

  /// This will be invoked when the app is opened from terminated state.
  ///
  /// Test on both Android device, Emulator, and iOS device. Simulator is not working.
  onMessageOpenedFromTermiated(RemoteMessage message) {
    // If it the message has data, then do some exttra work based on the data.
    onMessageOpenedShowMessage(message);
  }

  /// This will be invoked when the app is opened from backgroun state.
  ///
  /// Test on both Android device, Emulator, and iOS device. Simulator is not working.
  onMessageOpenedFromBackground(RemoteMessage message) {
    onMessageOpenedShowMessage(message);
  }

  onMessageOpenedShowMessage(RemoteMessage message) {
    /**
     * return if the the sender is also the current loggedIn user.
     */
    if (api.loggedIn && message?.data['senderIdx'] == "${api.user.idx}") return;

    /**
     * If the type is post then move it to a specific post.
     */
    if (message?.data['type'] == 'post') {
      open(
        RouteNames.forumList,
        arguments: {'postIdx': int.parse("${message.data['idx']}")},
        preventDuplicates: false,
      );
    }

    /**
     * If the type is chat then move it to chat room.
     */
    if (message?.data['type'] == 'chat') {
      api.firebaseAuth.authStateChanges().where((user) => user != null).take(1).listen((user) {
        openChatRoom(roomId: message.data['roomId']);
      });
    }
  }

Saving last message

• This is how to save the last message.

/// Room list chanegs event happens when any of the user room changes.
roomListChanges.listen((room) {
  if (room?.text != null) {
    if (room.senderUid != api.firebaseAuth.currentUser?.uid) { // if it's not my message.(not sent by me.)
      int seconds = room?.createdAt?.seconds;
      int lastMessageSeconds = GetStorage().read('lastMessageSeconds');
      if (lastMessageSeconds == null || seconds > lastMessageSeconds) { // if no message written before or it's newer(last) message.
        print('Going to save last message');
        GetStorage().write('lastMessageSeconds', seconds);
        GetStorage().write('lastMessage', room?.text);
      }
    } else {
      print('This is my chat. do not save');
    }
  }
});

• Below is to display.

class _ChatLastMessage extends State<ChatLastMessage> {
  String lastMessage = GetStorage().read('lastMessage');
  @override
  void initState() {
    super.initState();
    GetStorage().listenKey('lastMessage', (val) {
      if (mounted) setState(() => lastMessage = val);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Row(
      children: [
        Icon(Ionicons.ios_chatbubbles, color: white),
        spaceXs,
        Expanded(
          child: Text(
            lastMessage ?? '...',
            style: tsWhite,
            maxLines: 1,
            overflow: TextOverflow.ellipsis,
          ),
        ),
      ],
    );
  }
}