socket.io - can't send messages to a specific room in a socket

[iman2420]

I'm trying to set up my node server to update all the connected clients with new information in real-time. When I run the code below, the io.sockets.on('connection') callback is fired constantly, flooding the console with the message Client connected!, and the front-end is not being updated from socket.emit(). What am I doing wrong?

const port = process.env.PORT || 3000;
const app = require('http').createServer(function (req, res) {
});
app.listen(port);
const io = require('socket.io').listen(app, () => {
console.log('Server listening at port %d %s', port);
});

const pool = require('./socketMySql');
let numUsers = 0;
const users = {};


io.on('connection', (socket) => {
let addedUser = false;
socket.on('joinToClass', (classroom_id) => {
    const isArray = (classroom_id.toString().startsWith("["));
    if (isArray)
        classroom_id = JSON.parse(classroom_id);
    socket.join(parseInt(classroom_id), function () {
        let rooms = Object.keys(socket.rooms);
        console.log("joinToClass " + classroom_id + " rooms " + rooms);
    });
});

socket.on('leaveTheClass', (classroom_id) => {
    const isArray = (classroom_id.toString().startsWith("["));
    if (isArray)
        classroom_id = JSON.parse(classroom_id);
    socket.leave(classroom_id, function () {
        console.log("Socket now leave The Class " + classroom_id);
    });
});

// when the client emits 'add user', this listens and executes
socket.on('add user', (data) => {
    if (addedUser) return;
    data = JSON.parse(data);
    // we store the username in the socket session for this client
    socket.username = data.name;
    socket.family = data.family;
    socket.id = data.id;
    ++numUsers;
    addedUser = true;
    users[socket.id] = data.id;       
    // echo globally (all clients) that a person has connected
    socket.broadcast.emit('user joined', {
        username: socket.username,
        numUsers: numUsers,
        userId: socket.id
    });
});

// when the client emits 'typing', we broadcast it to others
socket.on('typing', async (data) => {
    data = JSON.parse(data);
    const classroomId = data.classroom_id;
    const typingData = {
        classroom_id: classroomId,
        userId: data.userId,
        exam_id: data.exam_id
    };
    io.sockets.in(parseInt(classroomId)).emit('typing', typingData);   //<==   NOT WORK
});

// when the client emits 'stop typing', we broadcast it to others
socket.on('stop typing', (data) => {
    data = JSON.parse(data);
    const classroomId = data.classroom_id;
    io.sockets.in(classroomId).emit('stop typing', { //<==   NOT WORK
        classroom_id: classroomId,
        userId: data.userId,
        exam_id: data.exam_id
    });      
});

// when the user disconnects.. perform this
socket.on('disconnect', () => {
    if (addedUser) {
        --numUsers;
        delete users[socket.id];      
        // echo globally that this client has left
        socket.broadcast.emit('user left', {
            username: socket.username,
            numUsers: numUsers,
            userId: socket.id
        });
    }
});
//just added
socket.on("error", (err) => {
        console.log("Caught flash policy server socket error: " + err.stack);
    }
)
});

In client side first call add user event when user come online.

When the user selects their class, event joinToClass is called to perform operation socket.join.

Event typing is called when the user is taking the exam, which I want to let the other class members know is taking the exam.

[Nibbler999]

socket.id is used internally by socket.io, you shouldn't overwrite it.

[joaohenriquepda]

I have same problem with versions:
"socket.io": "^2.3.0"
"socket.io-redis": "^5.4.0"

[iman2420]

@Nibbler999 You save my week. Thanks.