<div class="text-center">
  <div id="{{ chart.get_html_id }}" style="width: {{ chart.width }}px; height: {{ chart.height }}px;"></div>
  <a class="btn btn-sm btn-default" href="#" id="image-{{ chart.get_html_id }}"><span class="glyphicon glyphicon-save-file"></span> Télécharger l'image</a>
</div>
