show.html.erb

<% if @document.template.signature_position.exists? %>
     <div id="signature" style='position: absolute; left: <%= @document.template.signature_position.left %>px; top: <%= @document.template.signature_position.top %>px; '>
     <b style=" background-color: white; ">Electronically signed at: <%= @document.updated_at %></b> 
      <div style='opacity: 0.8;'>
        <canvas class="padShow" width="540" height="100" style="page-break-before: avoid;"></canvas>
      </div>
    </div>
    <script type="text/javascript">
    $(function() {
      renderSignature(<%= @document.signature.to_json.html_safe %>, 'div#signature');
    });
    </script>
<% end %>