require "redcarpet" require "nokogiri" require "rails_guides/markdown/renderer" module RailsGuides class Markdown def initialize(view, layout) @view = view @layout = layout @index_counter = Hash.new(0) @raw_header = "" @node_ids = {} end def render(body) @raw_body = body extract_raw_header_and_body generate_header generate_title generate_body generate_structure generate_index render_page end private def dom_id(nodes) dom_id = dom_id_text(nodes.last.text) # Fix duplicate node by prefix with its parent node if @node_ids[dom_id] if @node_ids[dom_id].size > 1 duplicate_nodes = @node_ids.delete(dom_id) new_node_id = "#{duplicate_nodes[-2][:id]}-#{duplicate_nodes.last[:id]}" duplicate_nodes.last[:id] = new_node_id @node_ids[new_node_id] = duplicate_nodes end dom_id = "#{nodes[-2][:id]}-#{dom_id}" end @node_ids[dom_id] = nodes dom_id end def dom_id_text(text) escaped_chars = Regexp.escape('\\/`*_{}[]()#+-.!:,;|&<>^~=\'"') text.downcase.gsub(/\?/, "-questionmark") .gsub(/!/, "-bang") .gsub(/[#{escaped_chars}]+/, " ").strip .gsub(/\s+/, "-") end def engine @engine ||= Redcarpet::Markdown.new(Renderer, no_intra_emphasis: true, fenced_code_blocks: true, autolink: true, strikethrough: true, superscript: true, tables: true) end def extract_raw_header_and_body if @raw_body =~ /^\-{40,}$/ @raw_header, _, @raw_body = @raw_body.partition(/^\-{40,}$/).map(&:strip) end end def generate_body @body = engine.render(@raw_body) end def generate_header @header = engine.render(@raw_header).html_safe end def generate_structure @headings_for_index = [] if @body.present? @body = Nokogiri::HTML.fragment(@body).tap do |doc| hierarchy = [] doc.children.each do |node| if node.name =~ /^h[3-6]$/ case node.name when "h3" hierarchy = [node] @headings_for_index << [1, node, node.inner_html] when "h4" hierarchy = hierarchy[0, 1] + [node] @headings_for_index << [2, node, node.inner_html] when "h5" hierarchy = hierarchy[0, 2] + [node] when "h6" hierarchy = hierarchy[0, 3] + [node] end node[:id] = dom_id(hierarchy) node.inner_html = "#{node_index(hierarchy)} #{node.inner_html}" end end end.to_html end end def generate_index if @headings_for_index.present? raw_index = "" @headings_for_index.each do |level, node, label| if level == 1 raw_index += "1. [#{label}](##{node[:id]})\n" elsif level == 2 raw_index += " * [#{label}](##{node[:id]})\n" end end @index = Nokogiri::HTML.fragment(engine.render(raw_index)).tap do |doc| doc.at("ol")[:class] = "chapters" end.to_html @index = <<-INDEX.html_safe

Chapters

#{@index}
INDEX end end def generate_title if heading = Nokogiri::HTML.fragment(@header).at(:h2) @title = "#{heading.text} — Ruby on Rails Guides" else @title = "Ruby on Rails Guides" end end def node_index(hierarchy) case hierarchy.size when 1 @index_counter[2] = @index_counter[3] = @index_counter[4] = 0 "#{@index_counter[1] += 1}" when 2 @index_counter[3] = @index_counter[4] = 0 "#{@index_counter[1]}.#{@index_counter[2] += 1}" when 3 @index_counter[4] = 0 "#{@index_counter[1]}.#{@index_counter[2]}.#{@index_counter[3] += 1}" when 4 "#{@index_counter[1]}.#{@index_counter[2]}.#{@index_counter[3]}.#{@index_counter[4] += 1}" end end def render_page @view.content_for(:header_section) { @header } @view.content_for(:page_title) { @title } @view.content_for(:index_section) { @index } @view.render(layout: @layout, html: @body.html_safe) end end end