How to send message to room clients when a client disconnects

Question

I want the server to send a message to all room clients when one of them disconnects.

Something like this:

socket.on('disconnect', function() {
    server.sockets.in(room).emit('bye');
});

But...

• How do I know which room to broadcast?
• What if the client has joined to multiple rooms?

Answer 1

After inspecting the sockets object, I came up with this solution:

socket.on('disconnect', function() {
    var rooms = io.sockets.manager.roomClients[socket.id];
    for (var room in rooms) {
        if (room.length > 0) { // if not the global room ''
            room = room.substr(1); // remove leading '/'
            console.log('user exits: '+room);
            server.sockets.in(room).emit('bye');
        }
    }
});