app.js

const express = require('express')
const app = express()
const nunjucks = require('nunjucks')
const fs = require('fs')
const path = require('path')
const port = (process.env.PORT || 3000)
const herokuApp = process.env.HEROKU_APP
const dto = require('directory-to-object')

// Set up views
const appViews = [
  path.join(__dirname, '/src/views/'),
  path.join(__dirname, '/src/components/'),
  path.join(__dirname, '/src/examples/')
]

// Configure nunjucks
nunjucks.configure(appViews, {
  autoescape: true,
  express: app,
  noCache: true,
  watch: true
})

// Set view engine
app.set('view engine', 'njk')

// Set up middleware to serve static assets
app.use('/public', express.static(path.join(__dirname, '/public')))
app.use('/icons', express.static(path.join(__dirname, '/public/icons')))

app.listen(port, () => {
  console.log('Listening on port ' + port + '   url: http://localhost:' + port)
})

// Routes

// Return an object representing the components directory
dto(path.resolve('./src/components'), (err, res) => {
  if (err) {
    console.log(err)
  }
  app.locals.componentsDirectory = res
})

// Index page - render the component list template
app.get('/', function (req, res) {
  res.render('component-list')
})

// Examples
app.get('/examples*', function (req, res) {
  res.render('index')
})

// Components
app.get('/components*', function (req, res) {
  var path = (req.params[0]).replace(/\//g, '')
  // If it isn't the isolated preview, render the component "detail" page
  if (path.indexOf('preview') === -1) {
    try {
      var componentNjk = fs.readFileSync('src/components/' + path + '/' + path + '.njk', 'utf8')
      var componentHtml = fs.readFileSync('src/components/' + path + '/' + path + '.html', 'utf8')

      res.locals.componentPath = path
      res.locals.componentNunjucksFile = componentNjk
      res.locals.componentHtmlFile = componentHtml
    } catch (e) {
      console.log('Error:', e.stack)
    }

    res.render(path, {
      componentPath: res.locals.componentPath,
      componentNunjucksFile: res.locals.componentNunjucksFile,
      componentHtmlFile: res.locals.componentHtmlFile
    },
    function (err, html) {
      if (err) {
        res.render(path + '/' + 'index', function (err2, html) {
          if (err2) {
            res.status(404).send(err + '<br>' + err2)
          } else {
            res.end(html)
          }
        })
      } else {
        res.end(html)
      }
    })
  } else {
    // Show the isolated component preview
    path = path.replace(/preview/g, '')
    res.locals.componentPath = path
    res.render('component-preview')
  }
})

// Config for Heroku

// If this is the Heroku demo app
if (herokuApp === 'DEMO') {
  app.use('/', express.static(path.join(__dirname, 'demo')))
}

// Disallow search index indexing
app.use(function (req, res, next) {
  // none - Equivalent to noindex, nofollow
  // noindex - Do not show this page in search results and do not show a "Cached" link in search results.
  // nofollow - Do not follow the links on this page
  res.setHeader('X-Robots-Tag', 'none')
  next()
})

app.get('/robots.txt', function (req, res) {
  res.type('text/plain')
  res.send('User-agent: *\nDisallow: /')
})