smashingnewsletter

#!/usr/bin/env ruby

require 'open-uri'
require 'nokogiri'

site_page = 'http://www.smashingmagazine.com/the-smashing-newsletter/'
rss_file = ENV['HOME'] + '/public_html/vitorgalvao/rss/smashingnewsletter.rss'

# get latest newsletter
newsletters_page = Nokogiri::HTML(open(site_page))
latest_newsletter_page_link = newsletters_page.css('article ul')[1].at('a').attr('href')
page = Nokogiri::HTML(open(latest_newsletter_page_link))

newsletter_title = page.at('h2').text
newsletter_link = latest_newsletter_page_link
newsletter_description = page.at('article').inner_html

# create feed
if !File.file?(rss_file)
  tmp_feed = Nokogiri::XML::Builder.new do |xml|
    xml.rss('version' => '2.0') {
      xml.channel {
        xml.title 'Smashing Newsletter'
        xml.link site_page
        xml.description 'Generates RSS feed for Smashing Newsletter posts'
      }
    }
  end
  rss_feed = Nokogiri::XML(tmp_feed.to_xml)
else
  rss_feed = Nokogiri::XML(File.open(rss_file))

  # abort if most recent item link is the same as the newly retrieved one
  # else save the most recent for later, and continue
  most_recent_item_link = rss_feed.at('item').at('link').content
  if (most_recent_item_link == newsletter_link)
    abort 'There are no new items to add'
  else
    recent_items = rss_feed.css('item')[0..9] # save recent items
    rss_feed.css('item').remove # removes all items
  end
end

# add new item to feed
Nokogiri::XML::Builder.with(rss_feed.at('channel')) do |xml|
  xml.item {
    xml.title newsletter_title
    xml.link newsletter_link
    xml.description newsletter_description
  }
end

# add previously grabbed items (if any) and save
rss_feed.at('channel').add_child(recent_items) unless recent_items.nil?

File.open(rss_file, 'w') do |f|
  f.puts rss_feed.to_xml
end