Joining socket io room on connect

Question

I am trying to make a logged in user to join a certain socket.io room on connect. According to any examples I found on the net I seem to have emit some action from client to be

Answer 1

This is easily achieved. All you need to do is pass along a query parameter that the server understands.

The following example isn't fully tested, but the idea will work. In this example, the roomname is determined from window.location.href on the client.

Client

// Last segment of path is roomName
var roomName = window.location.href.substr(window.location.href.lastIndexOf('/') + 1);
var socket = io({
    query: {
        roomName: roomName,
    },
});

Server

var io = require('socket.io')(server);
io.on('connection', function(socket) {
    var query = socket.handshake.query;
    var roomName = query.roomName;
    if(!roomName) {
        // Handle this as required
    }
    socket.join(roomName);
});

Answer 2

There is no .join() method on the client side. Rooms are purely a server-side construct and the client knows nothing about them.

Your first block of code is the desired way to do things. You send the server a message of your design asking it to join the socket to a room and the .join() is executed on the server side.

Answer 3

This should be what you need. Feel free to pass in whatever room name you want through the client. Only the server can handle assigning a socket to a room.

Server:

io.sockets.on('connection', function(socket) {
        socket.on('join', function(room) {
        socket.join(room);
    });
});

Client:

socket.emit('join', roomNum);