Function learningTrack

middleware/learning-track.js:6–98

(req, res, next)

import { getDeepDataByLanguage } from '../lib/get-data.js'

export default async function learningTrack(req, res, next) {
  const noTrack = () => {
    req.context.currentLearningTrack = {}
    return next()
  }

  if (!req.context.page) return next()

  const trackName = req.query.learn
  if (!trackName) return noTrack()

  let trackProduct = req.context.currentProduct
  const allLearningTracks = getDeepDataByLanguage('learning-tracks', req.language)
  let tracksPerProduct = allLearningTracks[trackProduct]

  // If there are no learning tracks for the current product, try and fall
  // back to the learning track product set as a URL parameter.  This handles
  // the case where a learning track has guide paths for a different product
  // than the current learning track product.
  if (!tracksPerProduct) {
    trackProduct = req.query.learnProduct
    tracksPerProduct = allLearningTracks[trackProduct]
  }
  if (!tracksPerProduct) return noTrack()

  const track = allLearningTracks[trackProduct][trackName]
  if (!track) return noTrack()

  // The trackTitle comes from a data .yml file and may use Liquid templating, so we need to render it
  const renderOpts = { textOnly: true }
  const trackTitle = await renderContent(track.title, req.context, renderOpts)

  const currentLearningTrack = { trackName, trackProduct, trackTitle }
  const guidePath = getPathWithoutLanguage(getPathWithoutVersion(req.pagePath))

  // The raw track.guides will return all guide paths, need to use getLinkData
  // so we only get guides available in the current version
  const trackGuides = await getLinkData(track.guides, req.context)

  const trackGuidePaths = trackGuides.map((guide) => {
    return getPathWithoutLanguage(getPathWithoutVersion(guide.href))
  })

  let guideIndex = trackGuidePaths.findIndex((path) => path === guidePath)

  // The learning track path may use Liquid version conditionals, handle the
  // case where the requested path is a learning track path but won't match
  // because of a Liquid conditional.
  if (guideIndex < 0) {
    guideIndex = await indexOfLearningTrackGuide(trackGuidePaths, guidePath, req.context)
  }

  // Also check if the learning track path is now a redirect to the requested
  // page, we still want to render the learning track banner in that case.
  // Also handles Liquid conditionals in the track path.
  if (guideIndex < 0) {
    for (const redirect of req.context.page.redirect_from || []) {
      if (guideIndex >= 0) break