---

<script src="/socket.io/socket.io.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script>
<script>
    var socket = io.connect('http://localhost:8080');

    // on connection to server, ask for user's name with an anonymous callback
    socket.on('connect', function(){
        // call the server-side function 'adduser' and send one parameter (value of prompt)
        socket.emit('adduser', prompt("What's your name?"));
    });

    // listener, whenever the server emits 'updatechat', this updates the chat body
    socket.on('updatechat', function (username, data) {

        $('#conversation').append('<b>'+username + ':</b> ' + data + '<br>');
    });

    // listener, whenever the server emits 'updaterooms', this updates the room the client is in
    socket.on('updaterooms', function(rooms, current_room) {
        $('#rooms').empty();
        $.each(rooms, function(key, value) {
            if(value == current_room){
                $('#rooms').append('<div>' + value + '</div>');
            }
            else {
                $('#rooms').append('<div><a href="#" onclick="switchRoom(\''+value+'\')">' + value + '</a></div>');
            }
        });
    });

    function switchRoom(room){
        socket.emit('switchRoom', room);
    }

    // on load of page
    $(function(){
        // when the client clicks SEND
        $('#datasend').click( function() {
            var message = $('#data').val();
            $('#data').val('');
            // tell server to execute 'sendchat' and send along one parameter
            socket.emit('sendchat', message);
        });

        // when the client hits ENTER on their keyboard
        $('#data').keypress(function(e) {
            if(e.which == 13) {
                $(this).blur();
                $('#datasend').focus().click();
            }
        });
    });

</script>

<style type="text/css">
#apDiv1 {
    position:absolute;
    width:200px;
    height:115px;
    z-index:1;
    left: 150px;
    top: 20px;
    background-color: #FF9900;
    display:none;
}
</style>

<div style="float:left;width:100px;border-right:1px solid black;height:300px;padding:10px;overflow:scroll-y;">
    <b>ROOMS</b>
    <div id="rooms"></div>
</div>
<div style="float:left;width:300px;height:250px;overflow:scroll-y;padding:10px;">
    <div id="conversation"></div>
    <input id="data" style="width:200px;" />
    <input type="button" id="datasend" value="send" />
</div>
<div id="apDiv1"></div>

---

---

var app = require('express').createServer()
var io = require('socket.io').listen(app);

app.listen(8080);

// routing
app.get('/', function (req, res) {
  res.sendfile(__dirname + '/index.html');
});

// usernames which are currently connected to the chat
var usernames = {};

// rooms which are currently available in chat
var rooms = ['room1','room2','room3'];

io.sockets.on('connection', function (socket) {

    // when the client emits 'adduser', this listens and executes
    socket.on('adduser', function(username){
        // store the username in the socket session for this client
        socket.username = username;
        // store the room name in the socket session for this client
        socket.room = 'room1';
        // add the client's username to the global list
        usernames[username] = username;
        // send client to room 1
        socket.join('room1');
        // echo to client they've connected
        socket.emit('updatechat', 'SERVER', 'you have connected to room1');
        // echo to room 1 that a person has connected to their room
        socket.broadcast.to('room1').emit('updatechat', 'SERVER', username + ' has connected to this room');
        socket.emit('updaterooms', rooms, 'room1');
    });

    // when the client emits 'sendchat', this listens and executes
    socket.on('sendchat', function (data) {
        // we tell the client to execute 'updatechat' with 2 parameters
        io.sockets.in(socket.room).emit('updatechat', socket.username, data);
    });

    socket.on('switchRoom', function(newroom){
        // leave the current room (stored in session)
        socket.leave(socket.room);
        // join new room, received as function parameter
        socket.join(newroom);
        socket.emit('updatechat', 'SERVER', 'you have connected to '+ newroom);
        // sent message to OLD room
        socket.broadcast.to(socket.room).emit('updatechat', 'SERVER', socket.username+' has left this room');
        // update socket session room title
        socket.room = newroom;
        socket.broadcast.to(newroom).emit('updatechat', 'SERVER', socket.username+' has joined this room');
        socket.emit('updaterooms', rooms, newroom);
    });

    // when the user disconnects.. perform this
    socket.on('disconnect', function(){
        // remove the username from global usernames list
        delete usernames[socket.username];
        // update list of users in chat, client-side
        io.sockets.emit('updateusers', usernames);
        // echo globally that this client has left
        socket.broadcast.emit('updatechat', 'SERVER', socket.username + ' has disconnected');
        socket.leave(socket.room);
    });
});

---