unordered-ui-bundle/tasks/preview-pages.js

'use strict'

const fs = require('fs-extra')
const handlebars = require('handlebars')
const { obj: map } = require('through2')
const path = require('path')
const requireFromString = require('require-from-string')
const vfs = require('vinyl-fs')
const yaml = require('js-yaml')

module.exports = (src, dest, siteSrc, siteDest, onComplete) => () =>
  Promise.all([
    loadSampleUiModel(siteSrc),
    compileLayouts(src),
    registerPartials(src),
    registerHelpers(src),
  ]).then(([uiModel, layouts]) =>
    vfs
      .src('**/*.html', { base: siteSrc, cwd: siteSrc })
      .pipe(
        map((file, enc, next) => {
          const compiledLayout = layouts[file.stem === '404' ? '404.hbs' : 'default.hbs']
          const siteRootPath = path.relative(path.dirname(file.path), path.resolve(siteSrc))
          uiModel.env = process.env
          uiModel.siteRootPath = siteRootPath
          uiModel.siteRootUrl = path.join(siteRootPath, 'index.html')
          uiModel.uiRootPath = path.join(siteRootPath, '_')
          uiModel.page.contents = file.contents.toString().trim()
          file.contents = Buffer.from(compiledLayout(uiModel))
          next(null, file)
        })
      )
      .pipe(vfs.dest(siteDest))
      .pipe(onComplete ? onComplete() : map((file, enc, next) => next()))
  )

function loadSampleUiModel (siteSrc) {
  return fs.readFile(path.join(siteSrc, 'ui-model.yml'), 'utf8').then((contents) => yaml.safeLoad(contents))
}

function registerPartials (src) {
  return new Promise((resolve, reject) =>
    vfs
      .src('partials/*.hbs', { base: src, cwd: src })
      .pipe(
        map((file, enc, next) => {
          handlebars.registerPartial(file.stem, file.contents.toString())
          next()
        })
      )
      .on('error', reject)
      .on('finish', resolve)
  )
}

function registerHelpers (src) {
  return new Promise((resolve, reject) =>
    vfs
      .src('helpers/*.js', { base: src, cwd: src })
      .pipe(
        map((file, enc, next) => {
          handlebars.registerHelper(file.stem, requireFromString(file.contents.toString()))
          next()
        })
      )
      .on('error', reject)
      .on('finish', resolve)
  )
}

function compileLayouts (src) {
  const layouts = {}
  return new Promise((resolve, reject) =>
    vfs
      .src('layouts/*.hbs', { base: src, cwd: src })
      .pipe(
        map((file, enc, next) => {
          layouts[file.basename] = handlebars.compile(file.contents.toString(), { preventIndent: true })
          next()
        })
      )
      .on('error', reject)
      .on('finish', () => resolve(layouts))
  )
}