//configure passport and express

  var socketIo = require("socket.io"),
    passportSocketIo = require("passport.socketio");

  var sio = socketIo.listen(webServer);


  //except for the optional fail and success the parameter object has the 
  //same attribute than the session middleware http://www.senchalabs.org/connect/middleware-session.html

  sio.set("authorization", passportSocketIo.authorize({
    cookieParser: express.cookieParser, //or connect.cookieParser
    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);
    }
  }));

  sio.sockets.on("connection", function(socket){
    console.log("user connected: ", socket.handshake.user.name);
    
    //filter sockets by user...
    var userGender = socket.handshake.user.gender, 
        opposite = userGender === "male" ? "female" : "male";

    passportSocketIo.filterSocketsByUser(sio, function (user) {
      return user.gender === opposite;
    }).forEach(function(s){
      s.send("a " + userGender + " has arrived!");
    });

  });