问题
I am trying to force ValidationError
to return a different status code than 400. This is what I did:
class MyValidationError(ValidationError):
status_code = HTTP_403_FORBIDDEN
and then in a serializer:
def validate_field(self, value):
raise MyValidationError
Why do I get 400 here instead of 403? An interesting thing is that if I use PermissionDenied
with a custom status code (I tried 204) instead of ValidationError
, it works as expected.
回答1:
The Django RestFramework serializer validates all possible fields and finally returns set of errors.
That is, suppose you are expecting two validation errors in serializer, in that one validation error is raised by MyValidationError
. In that case DRF obviously return HTTP 400
status code, because the design patterns of DRF not raising individual validation errors.
The serializer validation process done inside the is_valid() method and it raises ValidationError at the end of the method.
def is_valid(self, raise_exception=False):
....code
....code
if self._errors and raise_exception:
raise ValidationError(self.errors)
return not bool(self._errors)
and the ValidationError class raises HTTP 400
class ValidationError(APIException):
status_code = status.HTTP_400_BAD_REQUEST
default_detail = _('Invalid input.')
default_code = 'invalid'
.... code
Why PermissionDenaid returns custom status code?
In the is_valid() (source code) method, it catches only ValidationError
if not hasattr(self, '_validated_data'):
try:
self._validated_data = self.run_validation(self.initial_data)
except ValidationError as exc:
self._validated_data = {}
self._errors = exc.detail
else:
self._errors = {}
At that time, DRF directly raises a PermissionDenaid
exception and returns its own status code, which is customized by you
Conclusion
DRF Serializer ValidationError never returns status code other that HTTP 400
because it catches other sub validation error exceptions(if any) and atlast raises a major ValidationError
which return HTTP 400
status code by it's design pattern
Reference:
is_valid() source code
ValidationError class source code
回答2:
yo bruh just create your own exception class and reraise it in serializer
class ValidationError422(APIException):
status_code = status.HTTP_422_UNPROCESSABLE_ENTITY
class BusinessSerializer(serializers.ModelSerializer):
class Meta:
model = Business
fields = ('id', 'name')
def is_valid(self, raise_exception=False):
try:
return super(BusinessSerializer, self).is_valid(raise_exception)
except ValidationError as e:
raise ValidationError422(detail=e.detail)
来源:https://stackoverflow.com/questions/51566095/django-rest-framework-validationerror-always-returns-400