Question

To send something to all clients, you use:

io.sockets.emit('response', data);

To receive from clients, you use:

socket.on('cursor', function(data) {
  ...
});

How can I combine the two so that when recieving a message on the server from a client, I send that message to all users except the one sending the message?

socket.on('cursor', function(data) {
  io.sockets.emit('response', data);
});

Do I have to hack it around by sending the client-id with the message and then checking on the client-side or is there an easier way?

Answer 1

Here is my list (updated for 1.0):

// sending to sender-client only
socket.emit('message', "this is a test");

// sending to all clients, include sender
io.emit('message', "this is a test");

// sending to all clients except sender
socket.broadcast.emit('message', "this is a test");

// sending to all clients in 'game' room(channel) except sender
socket.broadcast.to('game').emit('message', 'nice game');

// sending to all clients in 'game' room(channel), include sender
io.in('game').emit('message', 'cool game');

// sending to sender client, only if they are in 'game' room(channel)
socket.to('game').emit('message', 'enjoy the game');

// sending to all clients in namespace 'myNamespace', include sender
io.of('myNamespace').emit('message', 'gg');

// sending to individual socketid
socket.broadcast.to(socketid).emit('message', 'for your eyes only');

// list socketid
for (var socketid in io.sockets.sockets) {}
 OR
Object.keys(io.sockets.sockets).forEach((socketid) => {});