docsify/packages/docsify-server-renderer/index.js

import * as tpl from '../../src/core/render/tpl'
import fetch from 'node-fetch'
import {AbstractHistory} from '../../src/core/router/history/abstract'
import {Compiler} from '../../src/core/render/compiler'
import {isAbsolutePath} from '../../src/core/router/util'
import {readFileSync} from 'fs'
import {resolve, basename} from 'path'
import resolvePathname from 'resolve-pathname'
import debug from 'debug'
import {prerenderEmbed} from '../../src/core/render/embed'

function cwd(...args) {
  return resolve(process.cwd(), ...args)
}

function mainTpl(config) {
  let html = `<nav class="app-nav${
    config.repo ? '' : ' no-badge'
  }"><!--navbar--></nav>`

  if (config.repo) {
    html += tpl.corner(config.repo)
  }
  if (config.coverpage) {
    html += tpl.cover()
  }

  html += tpl.main(config)

  return html
}

export default class Renderer {
  constructor({template, config, cache}) {
    this.html = template
    this.config = config = Object.assign({}, config, {
      routerMode: 'history'
    })
    this.cache = cache

    this.router = new AbstractHistory(config)
    this.compiler = new Compiler(config, this.router)

    this.router.getCurrentPath = () => this.url
    this._renderHtml(
      'inject-config',
      `<script>window.$docsify = ${JSON.stringify(config)}</script>`
    )
    this._renderHtml('inject-app', mainTpl(config))

    this.template = this.html
  }

  _getPath(url) {
    const file = this.router.getFile(url)

    return isAbsolutePath(file) ? file : cwd(`./${file}`)
  }

  async renderToString(url) {
    this.url = url = this.router.parse(url).path
    const {loadSidebar, loadNavbar, coverpage} = this.config

    const mainFile = this._getPath(url)
    this._renderHtml('main', await this._render(mainFile, 'main'))

    if (loadSidebar) {
      const name = loadSidebar === true ? '_sidebar.md' : loadSidebar
      const sidebarFile = this._getPath(resolve(url, `./${name}`))
      this._renderHtml('sidebar', await this._render(sidebarFile, 'sidebar'))
    }

    if (loadNavbar) {
      const name = loadNavbar === true ? '_navbar.md' : loadNavbar
      const navbarFile = this._getPath(resolve(url, `./${name}`))
      this._renderHtml('navbar', await this._render(navbarFile, 'navbar'))
    }

    if (coverpage) {
      let path = null
      if (typeof coverpage === 'string') {
        if (url === '/') {
          path = coverpage
        }
      } else if (Array.isArray(coverpage)) {
        path = coverpage.indexOf(url) > -1 && '_coverpage.md'
      } else {
        const cover = coverpage[url]
        path = cover === true ? '_coverpage.md' : cover
      }

      const coverFile = this._getPath(resolve(url, `./${path}`))

      this._renderHtml('cover', await this._render(coverFile), 'cover')
    }

    const html = this.html
    this.html = this.template

    return html
  }

  _renderHtml(match, content) {
    this.html = this.html.replace(new RegExp(`<!--${match}-->`, 'g'), content)

    return this.html
  }

  async _render(path, type) {
    let html = await this._loadFile(path)
    const {subMaxLevel, maxLevel} = this.config
    let tokens

    switch (type) {
      case 'sidebar':
        html =
          this.compiler.sidebar(html, maxLevel) +
          `<script>window.__SUB_SIDEBAR__ = ${JSON.stringify(
            this.compiler.subSidebar(subMaxLevel)
          )}</script>`
        break
      case 'cover':
        html = this.compiler.cover(html)
        break
      case 'main':
        tokens = await new Promise(r => {
          prerenderEmbed(
            {
              fetch: url => this._loadFile(this._getPath(url)),
              compiler: this.compiler,
              raw: html
            },
            r
          )
        })
        html = this.compiler.compile(tokens)
        break
      case 'navbar':
      case 'article':
      default:
        html = this.compiler.compile(html)
        break
    }

    return html
  }

  async _loadFile(filePath) {
    debug('docsify')(`load > ${filePath}`)
    let content
    try {
      if (isAbsolutePath(filePath)) {
        const res = await fetch(filePath)
        if (!res.ok) {
          throw Error()
        }
        content = await res.text()
        this.lock = 0
      } else {
        content = await readFileSync(filePath, 'utf8')
        this.lock = 0
      }
      return content
    } catch (e) {
      this.lock = this.lock || 0
      if (++this.lock > 10) {
        this.lock = 0
        return
      }

      const fileName = basename(filePath)
      const result = await this._loadFile(
        resolvePathname(`../${fileName}`, filePath)
      )

      return result
    }
  }
}

Renderer.version = '__VERSION__'