Structuring express.js applications

/* Main application entry file. Please note, the order of loading is important.
 * Configuration loading and booting of controllers and custom error handlers */

var express = require('express')
  , fs = require('fs')
  , utils = require('./lib/utils')
  , auth = require('./authorization')

// Load configurations
var config_file = require('yaml-config')
exports = module.exports = config = config_file.readConfig('config/config.yaml')

require('./db-connect')                // Bootstrap db connection

// Bootstrap models
var models_path = __dirname + '/app/models'
  , model_files = fs.readdirSync(models_path)
model_files.forEach(function (file) {
  if (file == 'user.js')
    User = require(models_path+'/'+file)
  else
    require(models_path+'/'+file)
})

var app = express.createServer()       // express app
require('./settings').boot(app)        // Bootstrap application settings

// Bootstrap controllers
var controllers_path = __dirname + '/app/controllers'
  , controller_files = fs.readdirSync(controllers_path)
controller_files.forEach(function (file) {
  require(controllers_path+'/'+file)(app)
})

require('./error-handler').boot(app)   // Bootstrap custom error handler
mongooseAuth.helpExpress(app)          // Add in Dynamic View Helpers
everyauth.helpExpress(app, { userAlias: 'current_user' })

// Start the app by listening on <port>
var port = process.env.PORT || 3000
app.listen(port)
console.log('Express app started on port '+port)

// Article schema

var ArticleSchema = new Schema({
    title       : {type : String, default : '', trim : true}
  , body        : {type : String, default : '', trim : true}
  , user        : {type : Schema.ObjectId, ref : 'User'}
  , created_at  : {type : Date, default : Date.now}
})

ArticleSchema.path('title').validate(function (title) {
  return title.length > 0
}, 'Article title cannot be blank')

ArticleSchema.path('body').validate(function (body) {
  return body.length > 0
}, 'Article body cannot be blank')

ArticleSchema.pre('save', function (next) {
  // do something before you save...
  next()
})

ArticleSchema.methods.uploadPhotos = function (file, callback) {
  // upload photos
  callback(uploadedFIle)
})

mongoose.model('Article', ArticleSchema)

Article
  .findOne({ title: 'abc' })
  .populate('user')
  .run(function (err, article) {
    // do something
    // article.user would be populated with fields in user schema
  })

module.exports = function(app, auth){

  // Edit an article
  app.get('/article/:id/edit', auth.requiresLogin, auth.article.hasAuthorization, function(req, res){
    res.render('articles/edit', {
      title: 'Edit '+req.article.title,
      article: req.article
    })
  })

  // Delete an article
  app.del('/article/:id', auth.requiresLogin, auth.article.hasAuthorization, function(req, res){
    var article = req.article
    article.remove(function(err){
      // req.flash('notice', 'Deleted successfully')
      res.redirect('/articles')
    })
  })
}

app.configure(function(){

  // set views path, template engine and default layout
  app.set('views', __dirname + '/app/views')
  app.set('view engine', 'jade')
  app.set('view options', { layout: 'layouts/default' })

  // contentFor & content view helper - to include blocks of content only on required pages
  app.use(function(req, res, next){
    // expose the current path as a view local
    res.local('path', url.parse(req.url).pathname)

    // assign content str for section
    res.local('contentFor', function(section, str){
      res.local(section, str)
    })

    // check if the section is defined and return accordingly
    res.local('content', function(section){
      if (typeof res.local(section) != 'undefined')
        return res.local(section)
      else
        return ''
    })
    next()
  })

  // bodyParser should be above methodOverride
  app.use(express.bodyParser())
  app.use(express.methodOverride())

  // cookieParser should be above session
  app.use(express.cookieParser())
  app.use(express.session({
    secret: 'noobjs',
    store: new mongoStore({
      url: config.db.uri,
      collection : 'sessions'
    })
  }))

  app.use(express.favicon())

  // routes should be at the last
  // app.use(app.router)
  app.use(mongooseAuth.middleware())
})

// Some dynamic view helpers
app.dynamicHelpers({
  request: function(req){
    return req
  },

  hasMessages: function(req){
    if (!req.session) return false
    return Object.keys(req.session.flash || {}).length
  },

  // flash messages
  messages: require('./lib/express-messages'),

  // dateformat helper. Thanks to gh-/loopj/commonjs-date-formatting
  dateformat: function(req, res) {
    return require('./lib/dateformat').strftime
  }
})

// show error on screen. False for all envs except development
// settmgs for custom error handlers
app.set('showStackError', false)

// configure environments
app.configure('development', function(){
  app.set('showStackError', true)
  app.use(express.static(__dirname + '/public'))
})

// gzip only in staging and production envs
app.configure('staging', function(){
  app.use(gzippo.staticGzip(__dirname + '/public'))
  app.enable('view cache')
})

app.configure('production', function(){
  app.use(gzippo.staticGzip(__dirname + '/public'))
  // view cache is enabled by default in production mode
})

app.use(express.logger(':method :url :status'))