message: Fix markup broken since cache related changes
diff: @@ -286,9 +286,12 @@ class BaseViz(object):
  def get_payload(self, query_obj=None):
  """Returns a payload of metadata and data"""
  payload = self.get_df_payload(query_obj)
  - df = payload['df']
  - if df is not None:
  +
  + df = payload.get('df')
  + if df is not None and len(df.index) == 0:
  + raise Exception('No data')
  payload['data'] = self.get_data(df)
  +
  del payload['df']
  return payload
  