changed datefield to match code layout of datetime and time changes

rest_framework/fields.py

@@ -1121,11 +1121,11 @@ class DateField(Field):
         self.fail('invalid', format=humanized_format)
 
     def to_representation(self, value):
-        output_format = getattr(self, 'format', api_settings.DATE_FORMAT)
-
         if not value:
             return None
 
+        output_format = getattr(self, 'format', api_settings.DATE_FORMAT)
+
         if output_format is None:
             return value