context-builder.js

const i18n = require('lib/i18n')
const electronReleases = require('electron-releases')
const electronLatestStableVersion = i18n.electronLatestStableTag.slice(1)
const { deps } = electronReleases.find(
  (release) => release.version === electronLatestStableVersion
)
const { getLanguageNativeName } = require('locale-code')
const rtlDetect = require('rtl-detect')
const Releases = require('../lib/releases')

// Supply all route handlers with a baseline `req.context` object
module.exports = function contextBuilder(req, res, next) {
  // Attach i18n object to request so any route handler can use it if needed
  req.i18n = i18n

  // This allows the language to be set per-request using a query param, so
  // folks can share a link like /docs/api/app?lang=fr-FR and know that
  // the recipient will see the doc in that language, regardless of their
  // language settings. If no query param is set, fall back to the default
  // language (or the one set in the cookie)
  if (req.query.lang) {
    req.language = req.query.lang
  }

  // If request language does not exist, fall back to English
  // e.g. /?lang=Foo
  if (!i18n.website[req.language]) req.language = 'en-US'

  const localized = i18n.website[req.language]

  // Page titles, descriptions, etc
  let page = Object.assign(
    {
      title: 'Electron',
      path: req.path,
    },
    i18n.website[req.language].pages[req.path]
  )

  if (req.path !== '/') {
    page.title = `${page.title} | Electron`
  }

  req.context = {
    electronLatestStableVersion,
    electronLatestStableTag: i18n.electronLatestStableTag,
    deps: deps,
    releases: new Releases(electronReleases),
    currentLocale: req.language,
    currentLocaleNativeName: getLanguageNativeName(req.language),
    languageDirection: rtlDetect.getLangDir(req.language),
    locales: i18n.locales,
    page: page,
    showAnnouncementBanner: true,
    localized: localized,
    cookies: req.cookies,
    hostname: `${req.protocol}://${req.get('host')}`,
  }

  if (req.path.startsWith('/docs')) {
    req.context.docs = i18n.docs[req.language]
  }

  return next()
}