Private channels in node.js and redis. How to? - node.js

Question

I wrote the simple script (app.js) to subscribe redis' channel
var app = require('express').createServer()
, io = require('socket.io').listen(app);
var redis = require("redis");
app.listen(8080);
////////////// Dev environment; replace by PERL in production use.
app.get('/', function (req, res) {
res.sendfile(__dirname + '/index.html');
});
//////////////
io.sockets.on('connection', function (socket) {
socket.subscribe = redis.createClient();
socket.subscribe.subscribe('chat');
socket.subscribe.on("message", function(channel, message) {
socket.send(message);
});
socket.on('disconnect', function() {
socket.subscribe.quit();
});
socket.on('close', function() {
socket.subscribe.quit();
});
});
Now, I want to make possible to subscribe to private channel for each user.
I tried to pass extra data via socket.io.connect like this:
<script src="/socket.io/socket.io.js"></script>
<script>
var socket = io.connect('http://localhost:8080', {'PRIVATE_ROOM_HASH': 'secret_hash'});
socket.on('message', function (data) {
console.log(data);
});
</script>
and then in app.js
...
io.sockets.on('connection', function (socket, args) {
socket.subscribe = redis.createClient();
socket.subscribe.subscribe(args.PRIVATE_ROOM_HASH);
socket.subscribe.on("message", function(channel, message) {
socket.send(message);
});
but it does not work.
Any ideas how to resolve private rooms' problem?
Thanks.

Answer 1

I don't think you can pass extra arguments to the socket.io connect command and then get them in the server. If I'm wrong someone correct me. I can't find this anywhere in the socket.io documentation.
Anyway, socket.io has built in support for rooms. On the client side, you would for example send a join event to the server with the name of the room
var socket = io.connect('http://localhost:8080');
socket.on('connect', function() {
socket.emit('join', 'secret_hash');
});
socket.on('message', function(msg) {
// got a messae!
});
And on the server, you would use the rooms feature.
io.sockets.on('connection', function(socket) {
socket.on('join', function(room) {
socket.join(room);
socket.on('message', function(msg) {
socket.broadcast.to(room).emit('message', msg);
});
});
});

Answer 2

No need to do that, since you'll be duplicating functionality. With Socket.IO you can make the client join rooms, like described on their github page:
var io = require('socket.io').listen(80);
io.sockets.on('connection', function (socket) {
socket.join('justin bieber fans');
socket.broadcast.to('justin bieber fans').emit('new fan');
io.sockets.in('rammstein fans').emit('new non-fan');
});
Also if you'd like real auth, the best would be with sessions, I recommend you read the article about Express, Socket.IO and sessions.