RSSFusion

gistfile1.rb

# RSS Fusion: combines multiple RSS feeds and prints out the last N sorted by date
require 'rss/1.0'
require 'rss/2.0'
require 'open-uri'

# sample feeds, replace with your own :-)
feeds = [ {:name => "Main", :url => "http://feeds.feedburner.com/Technoclippings"},
          {:name => "Art & Science", :url => "http://artscience.cyberclip.com/rss.xml"},
          {:name => "Tech", :url => "http://tech.cyberclip.com/rss.xml"},
          {:name => "Travel", :url => "http://travel.cyberclip.com/rss.xml"},
          {:name => "Cog", :url => "http://cog.cyberclip.com/rss.xml"}
        ]

class RSSFusion
  
  attr_reader :post
  
  def initialize(feeds, n = 10)
    @feeds = feeds
    @n = n
    @posts = {}
  end
  
  # fetch a single rss feed and store key attributes in @posts
  def fetch_rss_feed(url)
    feed = ""
    open(url) do |s| feed = s.read end
    rss = RSS::Parser.parse(feed, false)
    rss.items.each do |p| 
      @posts[p.date] = { :title => p.title, :url => p.link, :date => p.date, :desc => p.description }
    end
  end

  # fetches all feeds and iterates through N most recent posts yielding to user-supplied block
  def print_feeds
    @feeds.each { |f| fetch_rss_feed f[:url] }
    @posts.keys.sort.last(@n).reverse.each do |k|
      @post = @posts[k]
      yield
    end
  end

end

if ARGV.size != 2
  puts "Usage: rssfusion <N> <template>\nWhere <N> is the number of posts to print and <template> is a ruby file with formating instructions"
  exit -1
end

n = ARGV[0].to_i
template = IO.read(ARGV[1])
rss = RSSFusion.new(feeds, n)
# eval was the most expedient / flexible path for me, make sure you understand its security implications!
rss.print_feeds { eval(template) }

# example template file
# puts "#{rss.post[:title]}\t#{rss.post[:date].strftime('%m/%d/%y')}"