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Callback help - SocketIo room name not being relayed to server

I'm sending messages from my client using socketIo and would like to assign sockets to certain rooms. The room is being declared on the client side (based on url) but I can't get the roomName variable to pass to the server side code (which would be the first step in establishing the connection).

The [docs][1] show me how to 'emit' to a room once I have the room name but I'm new-ish to js and struggling with the callback component as a first step.

Client script

const socket = io();

const messages = document.getElementById('messages');
const form = document.getElementById('form');
const roomContainer = document.getElementById('room-container');
const input = document.getElementById('input');

socket.on('connection', (socket) => {
    socket.join('create', (roomName) => {
        socket.join(roomName);
        console.log("hello from the connection function on socketIo.js", roomName)
    });
});

form.addEventListener('submit', function (e) {
    console.log(roomName," logged from submit function in socketIo.js");
    e.preventDefault();
    if (input.value) {
        const alias = socket.id.slice(-5);
        socket.emit('chat message', alias + ": " + input.value);
        input.value = '';
    }
});

socket.on('chat message', function (msg) {
    const item = document.createElement('ul');
    item.textContent = msg;
    messages.appendChild(item);
    window.scrollTo(0, document.body.scrollHeight);
});

Server code

io.sockets.on('connection', (socket) => {
    socket.on('create', (roomName) => {
        socket.join(roomName);
        console.log("roomName function test");
    });

    socket.on('chat message', (msg) => {
        io.emit('chat message', msg);
        console.log("message to terminal from chat message");
    });
});

Right now, "message to terminal from chat message" prints with each message but "roomName function test" never prints. I'm somehow missing that entire function with how I've structured the code.

How do I get the client to pass the roomName to the server? [1]: https://socket.io/docs/v4/rooms/

about 4 years ago · Juan Pablo Isaza
1 answers
Answer question

0

I figured it out using this youtube video but code below for anyone who stumbles across this in the future.

Client side code running in script

const socket = io();

const messages = document.getElementById('messages');
const form = document.getElementById('form');
const roomContainer = document.getElementById('room-container');
const input = document.getElementById('input');


joinRoom = () => {
    socket.emit('join room', roomName);
}

joinRoom();

form.addEventListener('submit', (event) => {
    console.log(roomName, " logged from submit function in socketIo.js");
    event.preventDefault();
    if (input.value) {
        const alias = socket.id.slice(-5);
        socket.emit('chat message', alias + ": " + input.value);
        input.value = '';
    }
});

socket.on('chat message', (msg) => {
    const item = document.createElement('ul');
    item.textContent = msg;
    messages.appendChild(item);
    window.scrollTo(0, document.body.scrollHeight);
});

Server code running on app.js

io.on('connection', (socket) => {

    socket.on('join room', (data) => {
        socket.join(data);
        console.log(socket.id, " joined room ", data);

        socket.on('chat message', (msg) => {
            io.to(data).emit('chat message', msg);
            console.log("chat message function from server worked");
        })
    })

    socket.on("disconnect", () => {
        console.log("user ", socket.id, " disconnected from server")
    })
});
about 4 years ago · Juan Pablo Isaza Report
Answer question
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