How is the «Rebuild HTML» admin action implemented for a post?

dmitrii_fediuk · January 22, 2018, 11:11am

discourse/discourse/blob/v2.0.0.beta1/app/controllers/posts_controller.rb#L420-L427


def rebake
  guardian.ensure_can_rebake!


  post = find_post_from_params
  post.rebake!(invalidate_oneboxes: true)


  render body: nil
end

github.com

discourse/discourse/blob/v2.0.0.beta1/app/models/post.rb#L499-L517


def rebake!(opts = nil)
  opts ||= {}


  new_cooked = cook(raw, topic_id: topic_id, invalidate_oneboxes: opts.fetch(:invalidate_oneboxes, false))
  old_cooked = cooked


  update_columns(cooked: new_cooked, baked_at: Time.new, baked_version: BAKED_VERSION)


  # Extracts urls from the body
  TopicLink.extract_from(self)
  QuotedPost.extract_from(self)


  # make sure we trigger the post process
  trigger_post_process(true)


  publish_change_to_clients!(:rebaked)


  new_cooked != old_cooked
end

github.com

discourse/discourse/blob/v2.0.0.beta1/app/models/post.rb#L239-L269


def cook(raw, opts = {})
  # For some posts, for example those imported via RSS, we support raw HTML. In that
  # case we can skip the rendering pipeline.
  return raw if cook_method == Post.cook_methods[:raw_html]


  options = opts.dup
  options[:cook_method] = cook_method


  post_user = self.user
  options[:user_id] = post_user.id if post_user


  if add_nofollow?
    cooked = post_analyzer.cook(raw, options)
  else
    # At trust level 3, we don't apply nofollow to links
    options[:omit_nofollow] = true
    cooked = post_analyzer.cook(raw, options)
  end


  new_cooked = Plugin::Filter.apply(:after_post_cook, self, cooked)


  if post_type == Post.types[:regular]
    if new_cooked != cooked && new_cooked.blank?
      Rails.logger.debug("Plugin is blanking out post: #{self.url}\nraw: #{raw}")
    elsif new_cooked.blank?
      Rails.logger.debug("Blank post detected post: #{self.url}\nraw: #{raw}")
    end
  end


  new_cooked
end

github.com

discourse/discourse/blob/v2.0.0.beta1/app/models/post_analyzer.rb#L17-L35


def cook(raw, opts = {})
  cook_method = opts[:cook_method]
  return raw if cook_method == Post.cook_methods[:raw_html]


  if cook_method == Post.cook_methods[:email]
    cooked = EmailCook.new(raw).cook(opts)
  else
    cooked = PrettyText.cook(raw, opts)
  end


  result = Oneboxer.apply(cooked, topic_id: @topic_id) do |url, _|
    @found_oneboxes = true
    Oneboxer.invalidate(url) if opts[:invalidate_oneboxes]
    Oneboxer.cached_onebox(url)
  end


  cooked = result.to_html if result.changed?
  cooked
end

github.com

discourse/discourse/blob/v2.0.0.beta1/lib/oneboxer.rb#L93-L120


def self.apply(string_or_doc, args = nil)
  doc = string_or_doc
  doc = Nokogiri::HTML::fragment(doc) if doc.is_a?(String)
  changed = false


  each_onebox_link(doc) do |url, element|
    if args && args[:topic_id]
      url = append_source_topic_id(url, args[:topic_id])
    end
    onebox, _preview = yield(url, element)
    if onebox
      parsed_onebox = Nokogiri::HTML::fragment(onebox)
      next unless parsed_onebox.children.count > 0


      # special logic to strip empty p elements
      if  element.parent &&
          element.parent.node_name &&
          element.parent.node_name.downcase == "p" &&
          element.parent.children.count == 1
        element = element.parent
      end
      changed = true
      element.swap parsed_onebox.to_html
    end
  end


  Result.new(doc, changed)
end