Bugfix around empty compare_lag

panoramix/templates/panoramix/datasource.html

@@ -75,7 +75,7 @@
         <hr>
         <button type="button" class="btn btn-primary druidify">
           <i class="fa fa-bolt"></i>
-          Druidify!
+          Slice!
         </button>
         <button type="button" class="btn btn-default" id="save">
           <i class="fa fa-save"></i>

panoramix/viz.py

@@ -391,7 +391,7 @@ class BigNumberViz(BaseViz):
         df = df.sort(columns=df.columns[0])
         df['timestamp'] = df[[0]].astype(np.int64) // 10**9
         compare_lag = form_data.get("compare_lag", "")
-        compare_lag = int(compare_lag) if compare_lag.isdigit() else 0
+        compare_lag = int(compare_lag) if compare_lag and compare_lag.isdigit() else 0
         d = {
             'data': df.values.tolist(),
             'compare_lag': compare_lag,