NodeJS Express4

express generator

Install

npm install -g express-generator

express generator is Express command-line tool.
version check

express -V

Create application

express applicationname

applicationame is your application name

Install dependencies

This is same as Express3

npm install -g express-generator

Run

DEBUG=application:* ./bin/www

node app.js

Sample

Sample Default

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var routes = require('./routes/index');
var users = require('./routes/users');
http = require('http');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error('Not Found');
    err.status = 404;
    next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render('error', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});

module.exports = app;

Missing running codes

By template default, listen parts are missing.
Following codes should be added after module.exports = app;

app.set('port', 3000);
http.createServer(app).listen(app.get('port'), function(){
  console.log('Express server listening on port ' + app.get('port'));
});

Directory structure

application
|- app.js
|- package.json
|- views
   | - *.jade
|- routes
   | - *.js
|- models
    | - *.js
|- public
    |- javascripts
	      | - *.js
    |- images
	      | - *.png, *.jpg
    |- stylesheets
              | - *.css
|- test
    | - .*js
|- logs
    | - *.log

Ref

qiita