gistfile1.rb

# AV/base.rb
    def render(options = {}, local_assigns = {}, &block) #:nodoc:
      local_assigns ||= {}

      "<!--DBG #{options[:layout]} #{options[:file]} #{options[:partial]} #{options[:text]}-->"+
      if options.is_a?(String)
        ActiveSupport::Deprecation.warn(
          "Calling render with a string will render a partial from Rails 2.3. " +
          "Change this call to render(:file => '#{options}', :locals => locals_hash)."
        )

        render(:file => options, :locals => local_assigns)
      elsif options == :update
        update_page(&block)
      elsif options.is_a?(Hash)
        options = options.reverse_merge(:locals => {})
        if options[:layout]
          _render_with_layout(options, local_assigns, &block)
        elsif options[:file]
          _pick_template(options[:file]).render_template(self, options[:locals])
        elsif options[:partial]
          render_partial(options)
        elsif options[:inline]
          InlineTemplate.new(options[:inline], options[:type]).render(self, options[:locals])
        elsif options[:text]
          options[:text]
        end
      end+
      "<!--ENDDBG #{options[:file]} #{options[:partial]}-->"
    end

gistfile2.js

// js
      Event.addBehavior({
        '*:mousemove':function(evt) {
          var el=this;
          var s=null;
          do {
            el=el.parentNode;
            if (!el)
              break;
            // look for comments
            s=el.previousSibling;
            while (s) {
              if (s.nodeType==Node.COMMENT_NODE) {
                console.log(s.textContent);
              };
              s=s.previousSibling;
            }
          } while (el != null);
        }
      });