gistfile1.rb

#!/usr/bin/ruby

require 'rubygems'
require 'nokogiri'
require 'open-uri'
require 'rss/maker'
require 'syndication/atom'
require 'syndication/rss'
require 'syndication/content'

url = "http://www.heise.de/newsticker/heise-atom.xml"

#define filename
path = File.expand_path(File.dirname(__FILE__))
filename = "#{path}/heise.rss"

#load heise feed
xml = nil
open(url) do |http|
  xml = http.read
end
parser = Syndication::Atom::Parser.new
feed = parser.parse(xml)

#open cached feed
cacheditems = {}
if File.exists?(filename)
  open(filename) do |s| 
    rss = s.read
  cacheparser = Syndication::RSS::Parser.new
    cache = cacheparser.parse(rss)
  cache.items.each { |item| cacheditems[item.link] = item.description }
  end
end

content = RSS::Maker.make("2.0") do |m|
  m.channel.title = feed.title.txt
  m.channel.link = feed.links.first.href
  m.channel.about = "http://MYDOMAIN/heise.rss"
  m.channel.language = "de_DE"
  m.channel.description = feed.subtitle.txt
  m.items.do_sort = true 

  feed.entries.each do |i|
    item = m.items.new_item

    item.title = i.title.txt
    item.link = i.links.first.href
    item.date = Time.parse i.updated.to_s
  item.guid.content = i.id

  cached_item = cacheditems[item.link]

  if cached_item
    item.description = cached_item
    else
    html = nil
    open(item.link) do |http|
        html = http.read
      end
      doc = Nokogiri::HTML( html )
      content = doc.at("//div[@class='meldung_wrapper']")
      content.search("div").each { |x| x.remove }
      content.search("img").each { |img| img['src'] = img['src'].gsub(/^\//,'http://www.heise.de/') }
      item.description = content.to_s
    end

  end

end

File.open(filename, "w") do |f|
  f.write content
end

#puts File.read(filename)