User specific newsfeed socket.io and node.js

Question

User specific newsfeed socket.io and node.js

I am trying to create a newsfeed with Node.js, express, and sockets.io.

My problem is that socket.on("connection", function{}); doesn't give you the session id so I have no way of knowing which user is connected. I want to know if there is a way to pass the user id on connection from the session.

I have thought about on connecting the socket from the client side, sending a message to the server immediately after connection with the user id, and the server upon receiving the message with the user id sends back the proper newsfeed items.

I want to know if there is a better/ more scalable/efficient way of doing this.

Thanks a lot.

node.js
sockets
mongodb
express
news-feed

Answer 1

If you will authorize socket.io request, then you can filter users.

You have to serialize, deserialize user object in order to access properties with socket.io

passport.serializeUser(function (user, done) {
    done(null, user.id);
});

passport.deserializeUser(function (id, done) {
    User.findById(id, function (err, user) {
        done(err, user);
    });
});

Look at passportSocketIO. You can set authorization to incoming socket.io requests like this.

sio.set("authorization", passportSocketIo.authorize({
    key:    'express.sid',       //the cookie where express (or connect) stores its session id.
    secret: 'my session secret', //the session secret to parse the cookie
    store:   mySessionStore,     //the session store that express uses
    fail: function(data, accept) {     // *optional* callbacks on success or fail
      accept(null, false);             // second param takes boolean on whether or not to allow handshake
    },
    success: function(data, accept) {
      accept(null, true);
    }
  }));

Then you can filter out users in 'connection' callback like this.

sio.sockets.on("connection", function(socket){
    console.log("user connected: ", socket.handshake.user.name);

    //filter sockets by user...
    var userProperty = socket.handshake.user.property,             //property 
        // you can use user's property here.

    //filter users with specific property
    passportSocketIo.filterSocketsByUser(sio, function (user) {
      return user.property=== propertyValue;                  //filter users with specific property
    }).forEach(function(s){
      s.send("msg");
    });

  });