Fix default value handling for dotted sources #5375
Conversation
|
This looks great. It’s obviously too late for me, why does moving the guard clause fix the issue? |
|
On second thought, the guard is unneeded. |
44aa0e3 to
07258ca
Compare
|
I had originally just moved the guard, as I thought it was possible for the
Given the above, the # with guard
>>> get_attribute({'a': {'b': None}}, ['a', 'b', 'c'])
None
# without guard
>>> get_attribute({'a': {'b': None}}, ['a', 'b', 'c'])
Traceback (most recent call last):
File "<console>", line 1, in <module>
File "/Users/bagel/Documents/django-rest-framework/rest_framework/fields.py", line 100, in get_attribute
instance = getattr(instance, attr)
AttributeError: 'NoneType' object has no attribute 'c' |
|
This has caused a lot of my builds to go red as the expected keys are now missing. |
|
Adding |
|
I don't think it'll be enough in the case of nested serializers where I get an |
|
Hey folks. Just FYI, I'm looking at rolling a 3.7.1 this week (≈) so we can get a change/revert in here if we need to. |
|
I'm in the process of improving the docs and adding more tests. The below passes: def test_default_for_multiple_dotted_source(self):
class Serializer(serializers.Serializer):
c = serializers.CharField(default='x', source='a.b.c')
assert Serializer({}).data == {'c': 'x'}
assert Serializer({'a': {}}).data == {'c': 'x'}
assert Serializer({'a': None}).data == {'c': 'x'}
assert Serializer({'a': {'b': {}}}).data == {'c': 'x'}
assert Serializer({'a': {'b': None}}).data == {'c': 'x'}
assert Serializer({'a': {'b': {'c': 'abc'}}}).data == {'c': 'abc'}
def test_default_for_nested_serializer(self):
class NestedSerializer(serializers.Serializer):
a = serializers.CharField(default='1')
c = serializers.CharField(default='2', source='b.c')
class Serializer(serializers.Serializer):
nested = NestedSerializer()
assert Serializer({'nested': None}).data == {'nested': None}
assert Serializer({'nested': {}}).data == {'nested': {'a': '1', 'c': '2'}}
assert Serializer({'nested': {'a': '3', 'b': {}}}).data == {'nested': {'a': '3', 'c': '2'}}
assert Serializer({'nested': {'a': '3', 'b': {'c': '4'}}}).data == {'nested': {'a': '3', 'c': '4'}} |
|
yup, I failed to reproduce with regular serializers, but I'm having the issue with |
… when path components may be null. Ref encode#5375, encode#5727
… when path components may be null. Ref encode#5375, encode#5727
… when path components may be null. Ref encode#5375, encode#5727
This fixes #5371. In short, default handling works as expected when traversed attributes return an
object/dict, but not when one part of the traversal returnsNone.