Create an RSS feed in Rails Tian-优快云博客

本文介绍如何为Ruby on Rails博客创建RSS订阅源。通过简单的代码实现RSS规范，保持与读者的联系，并提供RSS元数据和文章详情。同时展示了如何让浏览器自动发现RSS订阅。

Not too long ago, I showed you how to create a blog archive for your Rails blog. Well, creating an RSS feed for your Rails blog might not necessarily increase SEO like a Google Sitemap can, but it's a helluva great way to stay in touch with your readers.

Here's a walk through for integrating RSS with your Rails blog.

RSS and Ruby on Rails - The Full Story

app/controllers/posts_controller.rb

@posts = Post.all(:select => "title, author, id, content, posted_at", :order => "posted_at DESC", :limit => 20) 

respond_to do |format|
   format.rss { render :layout => false }
end

In Rails, this call sends all RSS calls to index.rss.builder by default. Let's take a look at what that View does.

app/views/posts/index.rss.builder

This is where all the Railsy magic happens. In another language, in another web application framework, this could've easily been ugly. But with Rails, we're talking rainbows and ponies baby!

xml.instruct! :xml, :version => "1.0" 
xml.rss :version => "2.0" do
  xml.channel do
    xml.title "Your Blog Title"
    xml.description "A blog about software and chocolate"
    xml.link posts_url

    for post in @posts
      xml.item do
        xml.title post.title
        xml.description post.content
        xml.pubDate post.posted_at.to_s(:rfc822)
        xml.link post_url(post)
        xml.guid post_url(post)
      end
    end
  end
end

You just implemented the RSS specification in Ruby on Rails. Congrats! Let's keep moving, we're almost done.

app/views/layouts/application.html.erb

You can get browsers to auto-detect your Rails blog rss feed with a single line of Ruby on Rails code:

<%= auto_discovery_link_tag(:rss, "http://iblog.com") %>

Or, if you want, you can use straight XHTML to get browsers to auto-detect your Rails blog rss feed:

<link href="http://iblog.com" rel="alternate" title="RSS" type="application/rss+xml" />


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