Ability to use PolymorphicProxySerializer in extend_schema_field

[dkruk]

Sorry if such a possibility already exists, I could not find it in the documentation.

I have JSONField in my Django model and DictField in a serializer for this model. JSONField can contains three different types on data with determined fieldsets only. So, I have thee different serializers for the JSONField.

Below is a schematic representation of how I wanted to document what data is expected in the data field, but it doesn't work.
Could you tell me how you can solve this issue?
Thanks.

from drf_spectacular.utils import PolymorphicProxySerializer, extend_schema_field
from rest_framework import serializers

class FirstDataSerializer(serializers.Serializer):
    ...

class SecondDataSerializer(serializers.Serializer):
    ...

class ThirdDataSerializer(serializers.Serializer):
    ...

@extend_schema_field(
    PolymorphicProxySerializer(
        component_name='DataField',
        serializers=[
            FirstDataSerializer,
            SecondDataSerializer,
            ThirdDataSerializer,
        ],
        resource_type_field_name='data_field',
    )
)
class DataField(serializers.DictField):
    ...

class SomeModeSerializer(serializers.ModelSerializer):
    name = serializers.CharField(max_length=200)
    data = serializers.ListField(child=DataField(), min_length=0, max_length=100)

[tfranzel]

but it doesn't work.

hi! this is a bit underspecified. what is the error exactly? this looks ok to me on first glace, assuming First/Second/ThridDataSerializer have a data_field property

have you read the doc: https://drf-spectacular.readthedocs.io/en/latest/drf_spectacular.html#drf_spectacular.utils.PolymorphicProxySerializer ?

[dkruk]

I see the following warnings in the terminal. On the UI side, it is shown that the field expects a list of strings.

Warning #0: unable to extract field metadata from field "<drf_spectacular.utils.PolymorphicProxySerializer object at 0x7f642f3e1e20>" because it appears to be neither a Field nor a Serializer. Proper handling may require an Extension or @extend_serializer_field. Skipping metadata extraction. 
Warning #1: could not resolve serializer field "<drf_spectacular.utils.PolymorphicProxySerializer object at 0x7f642f3e1e20>". defaulting to "string"

have you read the doc: https://drf-spectacular.readthedocs.io/en/latest/drf_spectacular.html#drf_spectacular.utils.PolymorphicProxySerializer ?

yes, I read the docs.

[dkruk]

@tfranzel I tried the fix on my project - it works like a charm! Thank you!