jekyll/lib/jekyll/converters/markdown.rb

module Jekyll
  module Converters
    class Markdown < Converter
      safe true

      pygments_prefix "\n"
      pygments_suffix "\n"

      def setup
        return if @setup
        case @config['markdown']
          when 'redcarpet'
            begin
              require 'redcarpet'

              @renderer ||= Class.new(Redcarpet::Render::HTML) do
                def block_code(code, lang)
                  lang = lang && lang.split.first || "text"
                  output = add_code_tags(
                    Pygments.highlight(code, :lexer => lang, :options => { :encoding => 'utf-8' }),
                    lang
                  )
                end

                def add_code_tags(code, lang)
                  code = code.sub(/<pre>/,'<pre><code class="' + lang + '">')
                  code = code.sub(/<\/pre>/,"</code></pre>")
                end
              end

              @redcarpet_extensions = {}
              @config['redcarpet']['extensions'].each { |e| @redcarpet_extensions[e.to_sym] = true }
            rescue LoadError
              STDERR.puts 'You are missing a library required for Markdown. Please run:'
              STDERR.puts '  $ [sudo] gem install redcarpet'
              raise FatalException.new("Missing dependency: redcarpet")
            end
          when 'kramdown'
            begin
              require 'kramdown'
            rescue LoadError
              STDERR.puts 'You are missing a library required for Markdown. Please run:'
              STDERR.puts '  $ [sudo] gem install kramdown'
              raise FatalException.new("Missing dependency: kramdown")
            end
          when 'rdiscount'
            begin
              require 'rdiscount'
              @rdiscount_extensions = @config['rdiscount']['extensions'].map { |e| e.to_sym }
            rescue LoadError
              STDERR.puts 'You are missing a library required for Markdown. Please run:'
              STDERR.puts '  $ [sudo] gem install rdiscount'
              raise FatalException.new("Missing dependency: rdiscount")
            end
          when 'maruku'
            begin
              require 'maruku'

              if @config['maruku']['use_divs']
                require 'maruku/ext/div'
                STDERR.puts 'Maruku: Using extended syntax for div elements.'
              end

              if @config['maruku']['use_tex']
                require 'maruku/ext/math'
                STDERR.puts "Maruku: Using LaTeX extension. Images in `#{@config['maruku']['png_dir']}`."

                # Switch off MathML output
                MaRuKu::Globals[:html_math_output_mathml] = false
                MaRuKu::Globals[:html_math_engine] = 'none'

                # Turn on math to PNG support with blahtex
                # Resulting PNGs stored in `images/latex`
                MaRuKu::Globals[:html_math_output_png] = true
                MaRuKu::Globals[:html_png_engine] =  @config['maruku']['png_engine']
                MaRuKu::Globals[:html_png_dir] = @config['maruku']['png_dir']
                MaRuKu::Globals[:html_png_url] = @config['maruku']['png_url']
              end
            rescue LoadError
              STDERR.puts 'You are missing a library required for Markdown. Please run:'
              STDERR.puts '  $ [sudo] gem install maruku'
              raise FatalException.new("Missing dependency: maruku")
            end
          else
            STDERR.puts "Invalid Markdown processor: #{@config['markdown']}"
            STDERR.puts "  Valid options are [ maruku | rdiscount | kramdown ]"
            raise FatalException.new("Invalid Markdown process: #{@config['markdown']}")
        end
        @setup = true
      end
      
      def matches(ext)
        rgx = '(' + @config['markdown_ext'].gsub(',','|') +')'
        ext =~ Regexp.new(rgx, Regexp::IGNORECASE)
      end

      def output_ext(ext)
        ".html"
      end

      def convert(content)
        setup
        case @config['markdown']
          when 'redcarpet'
            @redcarpet_extensions[:fenced_code_blocks] = !@redcarpet_extensions[:no_fenced_code_blocks]
            @renderer.send :include, Redcarpet::Render::SmartyPants if @redcarpet_extensions[:smart]
            markdown = Redcarpet::Markdown.new(@renderer.new(@redcarpet_extensions), @redcarpet_extensions)
            markdown.render(content)
          when 'kramdown'
            # Check for use of coderay
            if @config['kramdown']['use_coderay']
              Kramdown::Document.new(content, {
                :auto_ids      => @config['kramdown']['auto_ids'],
                :footnote_nr   => @config['kramdown']['footnote_nr'],
                :entity_output => @config['kramdown']['entity_output'],
                :toc_levels    => @config['kramdown']['toc_levels'],
                :smart_quotes  => @config['kramdown']['smart_quotes'],

                :coderay_wrap               => @config['kramdown']['coderay']['coderay_wrap'],
                :coderay_line_numbers       => @config['kramdown']['coderay']['coderay_line_numbers'],
                :coderay_line_number_start  => @config['kramdown']['coderay']['coderay_line_number_start'],
                :coderay_tab_width          => @config['kramdown']['coderay']['coderay_tab_width'],
                :coderay_bold_every         => @config['kramdown']['coderay']['coderay_bold_every'],
                :coderay_css                => @config['kramdown']['coderay']['coderay_css']
              }).to_html
            else
              # not using coderay
              Kramdown::Document.new(content, {
                :auto_ids      => @config['kramdown']['auto_ids'],
                :footnote_nr   => @config['kramdown']['footnote_nr'],
                :entity_output => @config['kramdown']['entity_output'],
                :toc_levels    => @config['kramdown']['toc_levels'],
                :smart_quotes  => @config['kramdown']['smart_quotes']
              }).to_html
            end
          when 'rdiscount'
            rd = RDiscount.new(content, *@rdiscount_extensions)
            html = rd.to_html
            if rd.generate_toc and html.include?(@config['rdiscount']['toc_token'])
              html.gsub!(@config['rdiscount']['toc_token'], rd.toc_content.force_encoding('utf-8'))
            end
            html
          when 'maruku'
            Maruku.new(content).to_html
        end
      end
    end
  end
end