devsiteParseMD.py

import os
import re
import yaml
import logging
import markdown
import devsiteHelper
from google.appengine.ext.webapp.template import render

SOURCE_PATH = os.path.join(os.path.dirname(__file__), 'src/content/')
UNSUPPORTED_TAGS = [
  r'{% link_sample_button .+%}',
  r'{% include_code (.+)%}'
]

def parse(requestPath, fileLocation, content, lang='en'):
  template = 'gae/article.tpl'

  dateUpdated = re.search(r"{# wf_updated_on:[ ]?(.*)[ ]?#}", content)
  if dateUpdated is None:
    logging.warn('Missing wf_updated_on tag.')
    dateUpdated = 'Unknown'
  else:
    dateUpdated = dateUpdated.group(1)

  ## Injects markdown includes into the markdown as appropriate
  includes = re.findall(r'^<<.+?\.md>>(?m)', content)
  for includeTag in includes:
    fileName = includeTag.replace('<<', '').replace('>>', '')
    fileName = os.path.join(os.path.dirname(fileLocation), fileName)
    include = devsiteHelper.readFile(fileName, lang)
    if include is None:
      include = 'Warning: Unable to find included markdown file.\n\n'
    content = content.replace(includeTag, include)

  # Remove any comments {# something #}
  content = re.sub(r'{#.+?#}', '', content)
  content = re.sub(r'{% comment %}.*?{% endcomment %}(?ms)', '', content)

  # Show warning for unsupported elements
  for tag in UNSUPPORTED_TAGS:
    if re.search(tag, content) is not None:
      logging.error(' - Unsupported tag: ' + tag)
      replaceWith = '<aside class="warning">Web<strong>Fundamentals</strong>: '
      replaceWith += '<span>Unsupported tag: <code>' + tag + '</code></span></aside>'
      content = re.sub(tag, replaceWith, content)

  # Show warning for template tags
  if re.search('{{', content) is not None:
    logging.warn(' - Warning: possible unescaped template tag')

  # Render any DevSite specific tags
  content = devsiteHelper.renderDevSiteContent(content, lang)

  # If it's a markdown file, parse it to HTML
  content = re.sub(r'^Note: (.*?)\n^\n(?ms)', r'<aside class="note" markdown="1"><strong>Note:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Caution: (.*?)\n^\n(?ms)', r'<aside class="caution" markdown="1"><strong>Caution:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Warning: (.*?)\n^\n(?ms)', r'<aside class="warning" markdown="1"><strong>Warning:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Key Point: (.*?)\n^\n(?ms)', r'<aside class="key-point" markdown="1"><strong>Key Point:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Key Term: (.*?)\n^\n(?ms)', r'<aside class="key-term" markdown="1"><strong>Key Term:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Objective: (.*?)\n^\n(?ms)', r'<aside class="objective" markdown="1"><strong>Objective:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Success: (.*?)\n^\n(?ms)', r'<aside class="success" markdown="1"><strong>Success:</strong> <span>\1</span></aside>', content)
  content = re.sub(r'^Dogfood: (.*?)\n^\n(?ms)', r'<aside class="dogfood" markdown="1"><strong>Dogfood:</strong> <span>\1</span></aside>', content)

  # Adds a set of markdown extensions available to us on DevSite
  ext = [
    'markdown.extensions.attr_list', # Adds support for {: #someid }
    'markdown.extensions.meta', # Removes the meta data from the top of the doc
    'markdown.extensions.toc', # Generate the TOC for the right side
    'markdown.extensions.tables', # Support for Markdown Tables
    'markdown.extensions.def_list', # Support for definition lists
    'markdown.extensions.extra' # Support for markdown='1' in tags
  ]
  md = markdown.Markdown(extensions=ext)
  content = md.convert(content)

  # Reads the book.yaml file and generate the lefthand nav
  if 'book_path' in md.Meta and len(md.Meta['book_path']) == 1:
    bookPath = md.Meta['book_path'][0]
    bookYaml = devsiteHelper.parseBookYaml(bookPath, lang)

  if 'project_path' in md.Meta and len(md.Meta['project_path']) == 1:
    projectPath = md.Meta['project_path'][0]

  if 'full_width' in md.Meta and len(md.Meta['full_width']) == 1:
    template = 'gae/home.tpl'

  # Build the table of contents & transform so it fits within DevSite
  toc = md.toc
  toc = toc.strip()
  # Strips the outer wrapper and the page title from the doc
  toc = re.sub(r'<div class="toc">(.*?<ul>){2}(?s)', '', toc)
  toc = re.sub(r'</ul>\s*</li>\s*</ul>\s*</div>(?s)', '', toc)
  # Add appropriate classes
  toc = re.sub(r'<ul>', '<ul class="devsite-page-nav-list">', toc)
  toc = re.sub(r'<a href', '<a class="devsite-nav-title" href', toc)
  toc = re.sub(r'<li>', '<li class="devsite-nav-item">', toc)

  # Replaces <pre> tags with prettyprint enabled tags
  content = re.sub(r'^<pre>(?m)', r'<pre class="prettyprint">', content)

  # Get the page title from the markup.
  titleRO = re.search(r'<h1 class="page-title".*?>(.*?)<\/h1>', content)
  if titleRO:
    title = titleRO.group(1)
  else:
    title = ':('

  gitHubEditUrl = 'https://github.com/google/WebFundamentals/blob/'
  gitHubEditUrl += 'master/src/content/'
  gitHubEditUrl += fileLocation.replace(SOURCE_PATH, '')

  gitHubIssueUrl = 'https://github.com/google/WebFundamentals/issues/'
  gitHubIssueUrl += 'new?title=Feedback for: ' + title + ' ['
  gitHubIssueUrl += lang + ']&body='
  gitHubIssueUrl += gitHubEditUrl

  # Renders the content into the template
  return render(template, {
    'title': title,
    'announcementBanner': devsiteHelper.getAnnouncementBanner(projectPath, lang),
    'lowerTabs': devsiteHelper.getLowerTabs(bookYaml),
    'gitHubIssueUrl': gitHubIssueUrl,
    'gitHubEditUrl': gitHubEditUrl,
    'requestPath': requestPath.replace('/index', ''),
    'leftNav': devsiteHelper.getLeftNav(requestPath, bookYaml),
    'content': content,
    'toc': toc,
    'dateUpdated': dateUpdated,
    'lang': lang,
    'footerPromo': devsiteHelper.getFooterPromo(),
    'footerLinks': devsiteHelper.getFooterLinkBox()
    })