PresentablePrimaryKeyRelatedField creates issue in redoc documentation.

[techlearner96]

I have a serializer field which works differently for read and write. I used PresentablePrimaryKeyRelatedField for that.
e.g:
car_type = PresentablePrimaryKeyRelatedField(
queryset=CarType.objects.all(),
presentation_serializer=CarTypeSerializer,
read_source=None
)
This works well when accessing the api, like in request i give an integer value to car_type field and in response it gives a dictionary to car_type field. Api request-response thing worked well.
Issue is with swagger documentation. In documentation, it gives car_type as integer field in both request and response schema.
How can i deal with that?

[gokselcoban]

AFAIK, there is no solution for this right now. It needs to be improved.

If you are using drf-spectacular, PolymorphicProxySerializer may help. It allows you to show different serializers depending on the situation. You may define an input and output serializer and represent them differently.

Something like that:

# input/accept
car_type = PrimaryKeyRelatedField(
    queryset=CarType.objects.all(),
)

# output/response
car_type = CarTypeSerializer()

https://drf-spectacular.readthedocs.io/en/latest/drf_spectacular.html#drf_spectacular.utils.PolymorphicProxySerializer
https://drf-spectacular.readthedocs.io/en/latest/drf_spectacular.html?highlight=PolymorphicProxySerializer#drf_spectacular.utils.PolymorphicProxySerializer

[ckarli]

You can use OpenApiSerializerFieldExtension

from drf_extra_fields.relations import PresentablePrimaryKeyRelatedField
from drf_spectacular.extensions import OpenApiSerializerFieldExtension
from drf_spectacular.settings import spectacular_settings

class PresentablePrimaryKeyRelatedFieldSchemaExtension(OpenApiSerializerFieldExtension):
    target_class = PresentablePrimaryKeyRelatedField

    def map_serializer_field(self, auto_schema, direction):
        if direction == "response" and spectacular_settings.COMPONENT_SPLIT_REQUEST:
            return auto_schema._map_serializer_field(
                self.target.presentation_serializer, direction, bypass_extensions=True
            )
        else:
            return auto_schema._map_serializer_field(
                self.target, direction, bypass_extensions=True
            )