snippet.rb

  # Returns a link to url with the specified content, automatically adds 
  # rel="nofollow" and the external class to the link.
  def link_to_external(content, url, options = {})
    url = httpify_url(url)
    link_to content, url, options.merge(:rel => :nofollow, :class => "#{options[:class].to_s} external")
  end

  # Just like link_to_external, but uses the dehttpified url as the content.
  def link_to_external_url(url, options = {})
    link_to_external(h(dehttpify_url(url)), url, options)
  end
  
  # Adds http:// to a URL if missing.
  def httpify_url(url)
    if url.match(/^https?\:\/\//i)
      url
    else
      "http://#{url}"
    end
  end

  # Removes http:// from a URL if present.
  def dehttpify_url(url)
    if url.match(/^https?\:\/\//i)
      url.gsub(/^https?\:\/\//i, '')
    else
      url
    end
  end