The tiny boot js for node app.js

var express = require('express') // require is a function realized by nodejs to import and call other function 
var routes = require('./routes')
var http = require('http')
var path = require('path')
var fs = require('fs')
var app = express()

app.locals.title = 'Hello World'

app.configure(function(){
  app.set('port', process.env.PORT || 3000)
  app.set('views', __dirname + '/views') // _dirname is the current js folder, set the default views location
  app.set('view engine', 'jade') // set the view engine such as ejs
  app.use(express.favicon()) 
  app.use(express.logger('dev'))
  app.use(express.bodyParser()) // both bodyParser and methondOverride are extending from connect
  app.use(express.methodOverride())  // to simulate put / delete by <input name="_method" value="delete" />  
  app.use(app.router)
  app.use(express.static(path.join(__dirname, 'public')))
})

app.configure('development', function(){
  app.use(express.errorHandler())
})

app.get('/', function(req, res, next){
  res.render('index', {content: 'Oops'})
})

http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port', app.get('port'))
})