Allow to override store and field at widget level

Author: leplatrem

leaflet/forms/widgets.py

@@ -50,6 +50,6 @@ def render(self, name, value, attrs=None):
         attrs.update(id_map=map_id + '_map',
                      id_map_callback=map_id + '_map_callback',
                      modifiable=self.modifiable,
-                     geometry_field_class=attrs.get('geometry_field_class', 'L.GeometryField'),
-                     field_store_class=attrs.get('field_store_class', 'L.FieldStore'))
+                     geometry_field_class=attrs.get('geometry_field_class', getattr(self, 'geometry_field_class', 'L.GeometryField')),
+                     field_store_class=attrs.get('field_store_class', getattr(self, 'field_store_class', 'L.FieldStore')))
         return super(LeafletWidget, self).render(name, value, attrs)