Socket.io - Cant stop passing all data to all clients

Question

I am having a issue where I am pulling data from a DB via node mysql & Express and passing it via socket.io.... but there's an issue am running into.

All users are updating with the same data rather than unique data per user.

For example:

If user A has just logged in he can see all his account details. But when user B logs in right after he can then see all his details....but it then updates user A details to show user B details as well.

I am trying to ensure user A can can only see his own and same for user B.

I have tried numerous things to stop this happening via JQuery but cant seem to find a resolution.

Below I have trimmed down a the code to a basic example:

HTML

<a href=""><span id="id-val">User A</span></a>
<a href=""><span id="user-val"></span></a>

Server side

server = http.createServer(app),
io = require('socket.io').listen(server);

function SQLuserData(userval) {
    connection.getConnection(function (err, connection) {
        connection.query('SELECT val FROM test WHERE name= ?;',
            [userval],
            function (err, rows) {
            var accountval = rows[0]['val'];
            if (accountval) {
                console.log("Val : " + accountval);
                UserVal(accountval);
            } else {
                console.log("Error | Val: " + err);
            }
        });
        connection.release();
    });
}

//Socket.io connection socket
io.sockets.on('connection', function (socket) {
    socket.on('sqluser', function (userval) {
        SQLuserData(userval);
    });
});

//Pass val client side.
function UserVal(accountval) {
    io.sockets.emit("valsocket", accountval);
}

Client side

var socket = io.connect();
//Used to grab information for that user from serverside.
    $(document).ready(function () {
        var userval = $('#id-val').text();
        socket.emit('sqluser', userval);
    });

    //Grabs user value being passed from serverside and updates HTML.
    socket.on("valsocket", function (accountval) {
        $("#user_val").val(accountval);
    });

Does anyone have any advice or potential solutions?

Answer 1

I think you want to avoid emitting the account data to all connected users, which is what Socket.IO's emit method does. It might be better have the client send a GET request to the server and respond with the account details to the individual client.

Here are some resources if you choose to use an HTTP request over Socket.IO:

jQuery GET

Express Respond

Answer 2

you need to grab and store the socket.id for each connected user

var users = {};

//Socket.io connection socket
io.sockets.on('connection', function (socket) {
    socket.on('sqluser', function (userval) {  
        // 'userval' must be unique for each user
        users[userval] = socket.id;
        SQLuserData(userval);
    });
});

and then use the same id to emit data ti single socket

//Pass val client side.
function UserVal(accountval, userval) {
    io.sockets.socket(users[userval]).emit("valsocket", accountval);
}

for socket.io version 1.0 and above

io.to(users[userval]).emit("valsocket", accountval);

Answer 3

So basically the problem with your code is that you are not distinguishing between users . Since you are sending data through socket you need to be careful to whom you are sending data. You can use socketio-auth to create a type of authentication . And then send the data as socket.emit(event, data); Where socket is an individual object per user . You can also use a cookie based session to help you with this .