visualisation: return 0.0 for None measures in json_data (#38913)

bijoe/schemas.py

@@ -137,6 +137,12 @@ class Measure(Base):
         'expression': str,
     }
 
+    @property
+    def default_value(self):
+        if self.type in ['integer', 'percent']:
+            return 0
+        return None
+
 
 class Dimension(Base):
     __slots__ = ['name', 'label', 'type', 'join', 'value', 'value_label',

bijoe/visualization/utils.py

@@ -181,7 +181,7 @@ class Visualization(object):
         return data
 
     def default_cell(self):
-        return MeasureCell(measure=self.measure, value=None)
+        return MeasureCell(measure=self.measure, value=self.measure.default_value)
 
     def table_2d(self):
         '''Layout data into 2d tables'''

tests/test_schema1.py

@@ -192,11 +192,11 @@ def test_none_percent_json_data(schema1, app, admin):
     assert visu.json_data() == [
         {
             'coords': [{'value': u'2017'}, {'value': u'cat\xe92'}],
-            'measures': [{'value': None}]
+            'measures': [{'value': 0}]
         },
         {
             'coords': [{'value': u'2017'}, {'value': u'cat\xe93'}],
-            'measures': [{'value': None}]},
+            'measures': [{'value': 0}]},
         {
             'coords': [{'value': u'2017'}, {'value': u'cat\xe91'}],
             'measures': [{'value': 94.11764705882354}]},