webSocketServer node.js how to differentiate clients

Solution 1:

In nodejs you can directly modify the ws client and add custom attributes for each client separately. Also you have a global variable wss.clients and can be used anywhere. Please try the next code and try to connect at leat two clients:

var WebSocketServer = require('ws').Server;
var wss = new WebSocketServer({
    server: httpsServer
});


wss.getUniqueID = function () {
    function s4() {
        return Math.floor((1 + Math.random()) * 0x10000).toString(16).substring(1);
    }
    return s4() + s4() + '-' + s4();
};

wss.on('connection', function connection(ws, req) {
    ws.id = wss.getUniqueID();

    wss.clients.forEach(function each(client) {
        console.log('Client.ID: ' + client.id);
    });
});

You can also pass parameters directly in the client connection URL:

https://myhost:8080?myCustomParam=1111&myCustomID=2222

In the connection function you can get these parameters and to assign these parameters directly to your ws client:

wss.on('connection', function connection(ws, req) {

    const parameters = url.parse(req.url, true);

    ws.uid = wss.getUniqueID();
    ws.chatRoom = {uid: parameters.query.myCustomID};
    ws.hereMyCustomParameter = parameters.query.myCustomParam;
}

Solution 2:

You can simply assign users ID to an array CLIENTS[], this will contain all users. You can directly send message to all users as given below:

var WebSocketServer = require('ws').Server,
    wss = new WebSocketServer({port: 8080}),
    CLIENTS=[];

wss.on('connection', function(ws) {
    CLIENTS.push(ws);
    ws.on('message', function(message) {
        console.log('received: %s', message);
        sendAll(message);
    });
    ws.send("NEW USER JOINED");
});

function sendAll (message) {
    for (var i=0; i<CLIENTS.length; i++) {
        CLIENTS[i].send("Message: " + message);
    }
}