Dynamic rooms in Socket.io

Question

I'm new in node.js and socket.io. I didn't understand how to work with rooms. I'm creating something like a Private Messages. Each pair of users have their unique room.

From documentation:

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

But I need to create a room from client side. Because it's dynamic. How?

I met some examples https://gist.github.com/crtr0/2896891

server.js

io = socketio.listen(server);

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

room = "abc123";
io.sockets.in(room).emit('message', 'what is going on, party people?');

This line drives me crazy. It seems to me stupid. Because server never know which room to use. Server just can handle multiple rooms.

room = "abc123";

Please, help or explain.

Answer 1

In you above code you have fixed room to abc123 , that you need to make it dynamic for all connected clients . You can provide room create option to user also you can provide logic to change/rename/leave/join room from client. Basically in your client and server you can apply below logical changes.

Client logic to update or change room :

socket.emit('switchRoom', newRoom);

socket.on('updaterooms', function(rooms, current_room) {
  // Update new room logic

}

Server Logic to handle room change :

socket.on('switchRoom', function(newroom){
        // leave the current room (stored in session)
        socket.leave(socket.room);
        // join new room, received as function parameter
        socket.join(newroom);
        socket.emit('updatechat', 'SERVER', 'you have connected to '+ newroom);
        // sent message to OLD room
        socket.broadcast.to(socket.room).emit('updatechat', 'SERVER', socket.username+' has left this room');
        // update socket session room title
        socket.room = newroom;
        socket.broadcast.to(newroom).emit('updatechat', 'SERVER', socket.username+' has joined this room');
        socket.emit('updaterooms', rooms, newroom);
    });

Refer Below Example :

Socket.io Multi-room Example

Rooms and Namespace in socket.io