how can you tell which socket connection clicked a button using socket.io?

Question

if you have a a button on the page and you want to make sure the button cannot be clicked again before another socket clicks their button.

if socket a clicked i should d

Answer 1

Every socket.io session is automatically assigned a unique string as an id. On the server you can get it from:

socket.id

If you are inside a session (that is, the connection that returns the socket object) you can send messages back to the client by simply doing:

socket.emit('event name',data);

But if you want to send a message to a different session then you need to do:

io.sockets.socket(socket_id).emit('event name',data);

If you want to send a message to all connected sessions then just do:

io.emit('event name', data); // broadcast

---

If your application have state that needs to be managed, then one technique is to store them in an object using the socket id as the key:

var buttonState = {}

io.on('connection',function('socket'){
    // default button to off when socket connects:
    bottonState[socket.id] = 'off';

    socket.on('on button',function(){
        bottonState[socket.id] = 'on';
    })

    socket.on('off button',function(){
        bottonState[socket.id] = 'off';
    })
})

Now that you can manage the individual state for each individual client on the server you can use that to communicate them to other clients.