TipSnippet: Create a RSS feed

RSS is hot! So, you want to fit your new Rails app with one too! That’s easy, of course, but you just need to know what to do.

This snippet will show you how to create an RSS feed form your RESTful articles. I’ll assume you know how to generate a resource named ‘article’ with a title, body and the default created_at and updated_at attributes.

You’ll first need to add a new collection to your resource in config/routes.rb

1map.resources :articles, :collections => {:rss => :get}

This will expose your RSS feed as http://localhost:3000/articles;rss

Create a corresponding action in the articles controller in app/controllers/articles_controller.rb. This method fetches the ten latest articles.

1def rss
2  @articles = Article.find(:all, :limit => 10, :order => 'created_at DESC')
3  render :layout => false
4end

I assume you render your articles in a layout. The render method here prevents your layout from rendering to create a plain XML file (which is what an RSS feed is).

Next we create a view. This is not the regular RHTML you’re used to but RXML. This enables the XML generator which we’ll use to generate the RSS feed. Create app/views/articles/rss.rxml

 1xml.instruct! :xml, :version=>"1.0"
 2xml.rss(:version=>"2.0"){
 3  xml.channel{
 4    xml.title("My Great Blog")
 5    xml.link("http://www.example.com/")
 6    xml.description("My great blog about very interesting stuff!")
 7    xml.language('en-uk')
 8      for article in @articles
 9        xml.item do
10          xml.title(article.title)
11          xml.description(article.body)
12          xml.author("support@example.com")
13          xml.pubDate(article.created_at.strftime("%a, %d %b %Y %H:%M:%S %z"))
14          xml.link(article_url(article))
15          xml.guid(article_url(article))
16        end
17      end
18  }
19}

Well, that’s it. You now have a working RSS feed!

If you want to enable auto discovery, you should add the following line to the header of your layout. (Auto discovery enables that little RSS icon in the address bar of your browser.)

1<%= auto_discovery_link_tag(:rss, :controller => 'articles', :action => 'rss') %>

Share and enjoy! Thank you.

Written by