1 files changed, 82 insertions, 0 deletions
diff --git a/guides/rails_guides/markdown/renderer.rb b/guides/rails_guides/markdown/renderer.rb
new file mode 100644
index 0000000000..2f36af1fb3
--- /dev/null
+++ b/guides/rails_guides/markdown/renderer.rb
@@ -0,0 +1,82 @@
+module RailsGuides
+  class Markdown
+    class Renderer < Redcarpet::Render::HTML
+      def initialize(options={})
+        super
+      end
+
+      def block_code(code, language)
+        <<-HTML
+<div class="code_container">
+<pre class="brush: #{brush_for(language)}; gutter: false; toolbar: false">
+#{ERB::Util.h(code).strip}
+</pre>
+</div>
+HTML
+      end
+
+      def header(text, header_level)
+        # Always increase the heading level by, so we can use h1, h2 heading in the document
+        header_level += 1
+
+        %(<h#{header_level}>#{text}</h#{header_level}>)
+      end
+
+      def paragraph(text)
+        if text =~ /^(TIP|IMPORTANT|CAUTION|WARNING|NOTE|INFO|TODO)[.:](.*?)/
+          convert_notes(text)
+        elsif text =~ /^\[<sup>(\d+)\]:<\/sup> (.+)$/
+          linkback = %(<a href="#footnote-#{$1}-ref"><sup>#{$1}</sup></a>)
+          %(<p class="footnote" id="footnote-#{$1}">#{linkback} #{$2}</p>)
+        else
+          text = convert_footnotes(text)
+          "<p>#{text}</p>"
+        end
+      end
+
+      private
+
+        def convert_footnotes(text)
+          text.gsub(/\[<sup>(\d+)\]<\/sup>/i) do
+            %(<sup class="footnote" id="footnote-#{$1}-ref">) +
+              %(<a href="#footnote-#{$1}">#{$1}</a></sup>)
+          end
+        end
+
+        def brush_for(code_type)
+          case code_type
+            when 'ruby', 'sql', 'plain'
+              code_type
+            when 'erb'
+              'ruby; html-script: true'
+            when 'html'
+              'xml' # html is understood, but there are .xml rules in the CSS
+            else
+              'plain'
+          end
+        end
+
+        def convert_notes(body)
+          # The following regexp detects special labels followed by a
+          # paragraph, perhaps at the end of the document.
+          #
+          # It is important that we do not eat more than one newline
+          # because formatting may be wrong otherwise. For example,
+          # if a bulleted list follows the first item is not rendered
+          # as a list item, but as a paragraph starting with a plain
+          # asterisk.
+          body.gsub(/^(TIP|IMPORTANT|CAUTION|WARNING|NOTE|INFO|TODO)[.:](.*?)(\n(?=\n)|\Z)/m) do |m|
+            css_class = case $1
+                        when 'CAUTION', 'IMPORTANT'
+                          'warning'
+                        when 'TIP'
+                          'info'
+                        else
+                          $1.downcase
+                        end
+            %(<div class="#{css_class}"><p>#{$2.strip}</p></div>)
+          end
+        end
+    end
+  end
+end