django_filters.py -> _get_model_field : AttributeError: 'NoneType' object has no attribute 'split'

[pd-Shah]

Problem

In some cases filter_field.field_name is None. so there is an error:

Internal Server Error: /v1/schema/
Traceback (most recent call last):
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/django/core/handlers/exception.py", line 47, in inner
    response = get_response(request)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/django/core/handlers/base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/django/views/generic/base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/rest_framework/views.py", line 509, in dispatch
    response = self.handle_exception(exc)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/rest_framework/views.py", line 469, in handle_exception
    self.raise_uncaught_exception(exc)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/rest_framework/views.py", line 480, in raise_uncaught_exception
    raise exc
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/rest_framework/views.py", line 506, in dispatch
    response = handler(request, *args, **kwargs)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/views.py", line 67, in get
    return self._get_schema_response(request)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/views.py", line 74, in _get_schema_response
    return Response(generator.get_schema(request=request, public=self.serve_public))
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/generators.py", line 257, in get_schema
    paths=self.parse(request, public),
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/generators.py", line 231, in parse
    operation = view.schema.get_operation(
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/openapi.py", line 64, in get_operation
    parameters = self._get_parameters()
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/openapi.py", line 202, in _get_parameters
    **dict_helper(self._get_filter_parameters()),
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/openapi.py", line 377, in _get_filter_parameters
    parameters += filter_extension.get_schema_operation_parameters(self)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/contrib/django_filters.py", line 44, in get_schema_operation_parameters
    result += self.resolve_filter_field(
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/contrib/django_filters.py", line 80, in resolve_filter_field
    model_field = self._get_model_field(filter_field, model)
  File "/home/pd/Gits/coretrailer45/venv/lib64/python3.9/site-packages/drf_spectacular/contrib/django_filters.py", line 181, in _get_model_field
    path = filter_field.field_name.split('__')
AttributeError: 'NoneType' object has no attribute 'split'

for example I got this error by using django-property-filter. here is the code:

class Car(CommonModel):

    @property
    def price(self):
        return int(self.prices.last().title)


class CarFilter(PropertyFilterSet):
        property_fields = [
            ('price', PropertyNumberFilter, ['lt', 'exact']),
        ]

Solution

just check it before getting the attribute, filter_field.field_name is not None:, So:

    def _get_model_field(self, filter_field, model):
        if filter_field.field_name is not None:
            path = filter_field.field_name.split('__')
            return follow_field_source(model, path)

[tfranzel]

hi! that stacktrace is from an old version.

accounted for this non standard django-filter behavior. though you may still get warnings.

[tfranzel]

closing this issue for now. feel free to comment if anything is missing or not working and we will follow-up.