fix bug

abonapp/templates/abonapp/charts.html

@@ -9,6 +9,7 @@
                     <h3 class="panel-title">График использования</h3>
                 </div>
                 <div class="panel-body">
+                    {% if charts_data %}
                     <canvas id="netChart" width="300" height="100"></canvas>
                     <script type="text/javascript">
                         var myChart = new Chart('netChart', {
@@ -43,6 +44,9 @@
                             }
                         });
                     </script>
+                    {% else %}
+                    <h2>Данные не переданы</h2>
+                    {% endif %}
                 </div>
             </div>
         </div>

abonapp/views.py

@@ -745,7 +745,7 @@ def charts(request, gid, uid):
     return render(request, 'abonapp/charts.html', {
         'abon_group': abongroup,
         'abon': abon,
-        'charts_data': ','.join(charts_data),
+        'charts_data': ','.join(charts_data) if charts_data is not None else None,
         'time_min': int(midnight.timestamp()),
         'time_max': int((midnight + timedelta(hours=23, minutes=59, seconds=59)).timestamp())
     })