gistfile1.rb

  def download_pdf
    @pdf = Prawn::Document.new(:template => @format.zip.path)
    inspector = PDF::Inspector::Page.analyze(@pdf.render)
    @pdf.font 'Helvetica'
    @pdf.font_size = 8
    1.upto(inspector.pages.size) do |page|
      @pdf.go_to_page(page)
      @pdf.move_down 750
      @pdf.text "Prepared for #{current_user.name}"
    end
    send_data(@pdf.render, :filename => @format.zip_file_name, :type => "application/pdf")
  end