Adding support for Rouge syntax colorizer - issue #275

Gemfile

@@ -31,6 +31,7 @@ gem 'rdiscount'
 gem 'rdoc'
 gem 'redcarpet'
 gem 'RedCloth'
+gem 'rouge'
 gem 'rubypants'
 gem 'sass', '~> 3.2.2'
 gem 'slim'

Gemfile.lock

@@ -119,6 +119,7 @@ GEM
     ref (1.0.5)
     rest-client (1.6.7)
       mime-types (>= 1.16)
+    rouge (1.3.3)
     ruby-hmac (0.4.0)
     rubypants (0.2.0)
     sass (3.2.12)
@@ -190,6 +191,7 @@ DEPENDENCIES
   rdiscount
   rdoc
   redcarpet
+  rouge
   rubocop!
   rubypants
   sass (~> 3.2.2)

lib/nanoc/filters/colorize_syntax.rb

@@ -34,6 +34,7 @@ class ColorizeSyntax < Nanoc::Filter
     # * `:pygmentsrb` for [pygments.rb](https://github.com/tmm1/pygments.rb),
     #   a Ruby interface for [Pygments](http://pygments.org/)
     # * `:simon_highlight` for [Highlight](http://www.andre-simon.de/doku/highlight/en/highlight.html)
+    # * `:rouge` for [Rouge](https://github.com/jayferd/rouge/)
     #
     # Additional colorizer implementations are welcome!
     #
@@ -292,9 +293,26 @@ def coderay_postprocess(language, element)
       element.swap div_outer
     end
 
+    # Runs the content through [Rouge](https://github.com/jayferd/rouge/.
+    #
+    # @api private
+    #
+    # @param [String] code The code to colorize
+    #
+    # @param [String] language The language the code is written in
+    #
+    # @return [String] The colorized output
+    def rouge(code, language, params = {})
+      require 'rouge'
+
+      formatter = Rouge::Formatters::HTML.new(:css_class => params[:css_class] || "highlight")
+      lexer = Rouge::Lexer.find_fancy(language, code) || Rouge::Lexers::PlainText
+      formatter.format(lexer.lex(code))
+    end
+
   protected
 
-    KNOWN_COLORIZERS = [ :coderay, :dummy, :pygmentize, :pygmentsrb, :simon_highlight ]
+    KNOWN_COLORIZERS = [ :coderay, :dummy, :pygmentize, :pygmentsrb, :simon_highlight, :rouge ]
 
     # Removes the first blank lines and any whitespace at the end.
     def strip(s)

test/filters/test_colorize_syntax.rb

@@ -375,4 +375,58 @@ def foo
     end
   end
 
+  def test_rouge
+    if_have 'rouge', 'nokogiri' do
+      # Create filter
+      filter = ::Nanoc::Filters::ColorizeSyntax.new
+
+      # Get input and expected output
+      input = <<EOS
+before
+<pre><code class="language-ruby">
+  def foo
+  end
+</code></pre>
+after
+EOS
+      expected_output = <<EOS
+before
+<pre><code class=\"language-ruby\"><pre class=\"highlight\">  <span class=\"k\">def</span> <span class=\"nf\">foo</span>
+  <span class=\"k\">end</span></pre></code></pre>
+after
+EOS
+
+      # Run filter
+      actual_output = filter.setup_and_run(input, :default_colorizer => :rouge)
+      assert_equal(expected_output, actual_output)
+    end
+  end
+
+  def test_rouge_with_css_class
+    if_have 'rouge', 'nokogiri' do
+      # Create filter
+      filter = ::Nanoc::Filters::ColorizeSyntax.new
+
+      # Get input and expected output
+      input = <<EOS
+before
+<pre><code class="language-ruby">
+  def foo
+  end
+</code></pre>
+after
+EOS
+      expected_output = <<EOS
+before
+<pre><code class=\"language-ruby\"><pre class=\"my-class\">  <span class=\"k\">def</span> <span class=\"nf\">foo</span>
+  <span class=\"k\">end</span></pre></code></pre>
+after
+EOS
+
+      # Run filter
+      actual_output = filter.setup_and_run(input, :default_colorizer => :rouge, :rouge => { :css_class => 'my-class' })
+      assert_equal(expected_output, actual_output)
+    end
+  end
+
 end