Socket.io - Implementing a user-socket association map for private messaging

Question

I\'m trying to create a private messaging system using socket.io

In order to associate the users with their sockets, most sites are suggesting something like this:

Answer 1

you can Send additional data on socket connection like this:

 client side :

     var c = io.connect('http://localhost:3000/', { query: "userId=value01" });



server side :
 // extract userId param from connected url
 io.on('connection', function(socket) {
      var socket_param_userId = socket.handshake['query']['userId'];
      console.log(socket_param_userId);  //show value01
});