module HtmlTools
    def add_to_url(string)
      doc = Nokogiri::HTML.parse(self)
      doc.css("a").each do |link|
        link.attributes["href"].value = "#{link.attributes["href"].value}#{string}"
      end
      doc.to_s
    end
  end

  def markdown(string)
    options = [:hard_wrap, :filter_html, :autolink, :no_intraemphasis, :fenced_code, :gh_blockcode]
    redcarpet = Redcarpet.new(string,*options).to_html.extend(HtmlTools)
    (redcarpet.add_to_url("?utm_campain=newsletter").to_html).html_safe
  end