Extended maintenance of Ruby 1.9.3 ended on February 23, 2015. Read more
Really Simple Syndication (RSS) is a family of formats that describe ‘feeds,’ specially constructed XML documents that allow an interested person to subscribe and receive updates from a particular web service. This portion of the standard library provides tooling to read and create these feeds.
The standard library supports RSS 0.91, 1.0, 2.0, and Atom, a related format. Here are some links to the standards documents for these formats:
If you’d like to read someone’s RSS feed with your Ruby code, you’ve come to the right place. It’s really easy to do this, but we’ll need the help of open-uri:
require 'rss' require 'open-uri' url = 'http://www.ruby-lang.org/en/feeds/news.rss' open(url) do |rss| feed = RSS::Parser.parse(rss) puts "Title: #{feed.channel.title}" feed.items.each do |item| puts "Item: #{item.title}" end end
As you can see, the workhorse is RSS::Parser#parse, which takes the source of the feed and a parameter that performs validation on the feed. We get back an object that has all of the data from our feed, accessible through methods. This example shows getting the title out of the channel element, and looping through the list of items.
Producing our own RSS feeds is easy as well. Let’s make a very basic feed:
require "rss" rss = RSS::Maker.make("atom") do |maker| maker.channel.author = "matz" maker.channel.updated = Time.now.to_s maker.channel.about = "http://www.ruby-lang.org/en/feeds/news.rss" maker.channel.title = "Example Feed" maker.items.new_item do |item| item.link = "http://www.ruby-lang.org/en/news/2010/12/25/ruby-1-9-2-p136-is-released/" item.title = "Ruby 1.9.2-p136 is released" item.updated = Time.now.to_s end end puts rss
As you can see, this is a very Builder-like DSL. This code will spit out an Atom feed with one item. If we needed a second item, we’d make another block with maker.items.new_item and build a second one.
Copyright © 2003-2007 Kouhei Sutou <kou@cozmixng.org>
You can redistribute it and/or modify it under the same terms as Ruby.
There is an additional tutorial by the author of RSS at: www.cozmixng.org/~rwiki/?cmd=view;name=RSS+Parser%3A%3ATutorial.en
For backward compatibility
Raised when an unexpected tag is encountered.
Raised when an unknown conversion error occurs.
Commenting is here to help enhance the documentation. For example, code samples, or clarification of the documentation.
If you have questions about Ruby or the documentation, please post to one of the Ruby mailing lists. You will get better, faster, help that way.
If you wish to post a correction of the docs, please do so, but also file bug report so that it can be corrected for the next release. Thank you.
If you want to help improve the Ruby documentation, please visit Documenting-ruby.org.