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 disable the button until another socket sends a message that they clicked their button and back and fourth.

$(".buttonTurns").on("click", function(){
        socket.emit("turnbutton click")
})

and they dont input any names when they connect

check this out http://stackoverflow.com/questions/4647348/send-message-to-specific-client-with-socket-io-and-node-js — VMcreator, Aug 10 '15 at 06:10
I think that thread has the answer you've been looking for, the idea is to save the socket id of every client and you can access them via io.sockets.socket(savedSocketId).emit(...). — VMcreator, Aug 10 '15 at 06:12

score 0 · Answer 1 · edited May 23 '17 at 11:44

You can set a UUID for each client (either client side javascript or server side javascript).

For a server side solution:

As @slebetman mentioned in the comments, socket.io has a built-in unique identifier for each socket.

as @slebetman suggested in his answer, to get the socket's unique ID () see his answer for more details):

// v0.6.x
var sid = socket.sessionId;    

// v0.7.x
var sid = socket.id;

For a client side solution:

If you set the unique ID on the client's side, than you probably need to create your own unique ID.

I took the following code from 6 revs and Briguy37's answer to a question here on this site:

function generateUUID(){
    var d = new Date().getTime();
    var uuid = 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
        var r = (d + Math.random()*16)%16 | 0;
        d = Math.floor(d/16);
        return (c=='x' ? r : (r&0x3|0x8)).toString(16);
    });
    return uuid;
};

The randomness should be strong enough for all your clients to have a unique identifier using this ID generator. This should work with the code you wanted to use regarding your question here.

This is not necessary since socket.io already assigns a unique string as id for each socket. — slebetman, Aug 11 '15 at 01:18
@slebetman thanks, I didn't know that. I'll update shortly, when I get to my computer. — Myst, Aug 11 '15 at 01:19

slebetman · Accepted Answer · 2015-08-11T01:33:06.760

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.

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

2 Answers2

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