rss_renderer.rb

# Usage:

respond_to :rss, :only => [:index]

def index
  @deals = Deal.by_city(@city).limit(15)
  respond_with(@deals) do |format|
    format.rss { render :rss => @deals, :title => "KupiKon", :item => { :title => :title, :description => :description }}
  end
end

Mime::Type.register "application/rss+xml", :rss

ActionController.add_renderer :rss do |data, options|
  self.content_type ||= Mime::XML
  self.response_body = data.to_xml(options)
  xml = Builder::XmlMarkup.new(:indent => 2)
  
  xml.instruct!(:xml, :encoding => "UTF-8")

  xml.rss "version" => "2.0" do
   xml.channel do

     xml.title       options[:title]
     xml.link        root_path
     xml.description options[:description]

     data.each do |item|
       xml.item do
         xml.title       item.send(options[:item][:title])
         xml.link        url_for(item)
         xml.description item.send(options[:item][:description])
         xml.guid        url_for(item)
       end
     end

   end
  end
  self.response_body = xml.target!
end