a simple chat system

application.js

var q= function(s){ return document.getElementById(s) }

function send(){
  var input = q('text');
  socket.send(input.value);
  input.value = '';
}

var socket = new io.Socket(null, {
  port: 8001,
  rememberTransport: false
});

socket.on('message', function(message){
  var el = document.createElement('p');
  el.innerHTML = message;
  q('chat').appendChild(el);
});

socket.connect();

index.jade

!!! 5
html(lang="en")
  head
    title chat
    meta(charset="utf-8")
    link(rel="stylesheet", href="/master.css")
    script(src="http://cdn.socket.io/stable/socket.io.js")
    script(src="/application.js")
  body
    h1 Sample chat client
    div#chat
    form#form(onsubmit="send();return false")
      input#text(type="text", autocomplete="off")

master.css

#chat p { 
  padding: 8px; 
  margin: 0; 
}
#chat p:nth-child(odd) { 
  background: #F6F6F6; 
}
form { 
  background: #444; 
  padding: 5px 10px; 
}
form input[type=text] { 
  width: 98%; 
  padding: 5px; 
  background: #fff; 
}

package.json

{
  "name": "simplechat",
  "version": "0.0.2",
  "dependencies": {
    "coffee-script": "1.0.1",
    "connect": "1.3.0",
    "express": "2.2.1",
    "jade": "0.10.4",
    "socket.io": "0.6.17"
  }
} 

server.coffee

express = require "express"
socketio = require "socket.io"

app = express.createServer express.static(__dirname + '/public')
app.set('view engine', 'jade')

app.get "/", (req, rsp) ->
  rsp.render 'index', { layout: false }

app.all "*", (req, rsp) ->
  rsp.send 404

app.listen process.env.PORT || 8001

socket = socketio.listen(app)

socket.on "connection", (client) ->
  client.send "welcome!"
  client.broadcast "#{client.sessionId} connected"

  client.on "message", (message) ->
    client.send "you: #{message}"
    client.broadcast "#{client.sessionId}: #{message}"

  client.on "disconnect", ->
    client.broadcast "#{client.sessionId} disconnected"

console.log "app listening on port #{ app.address().port }..."