Are Serializer and BaseSerializer supported?

Hi,

I am using DRF’s serializers.Serializer and serializers.BaseSerializer in a few places. I am running into errors because spectacular tries to access attributes on the serializer that are not present.

https://github.com/tfranzel/drf-spectacular/blob/deb83250f078ed4bce17b12972e098409ac69ec9/drf_spectacular/openapi.py#L763 throws AttributeError because my BaseSerializer subclass does not have fields.

https://github.com/tfranzel/drf-spectacular/blob/deb83250f078ed4bce17b12972e098409ac69ec9/drf_spectacular/openapi.py#L526 throws AttributeError because my Serializer subclass does not have Meta.

• Is it intended that spectacular only supports ModelSerializer subclasses, or am I maybe missing something here?
• Is there a good workaround for this?
• As a last resort solution, is there an API / pattern that allows me to manually define the schema instead of relying on inspection? I checked https://drf-spectacular.readthedocs.io/en/latest/customization.html, but I am not sure what the right approach would be in this case. A custom preprocessing hook maybe?

[tfranzel]

I have revisited this issue and I was too quick to reject the use case. It is in fact possible to use ReadOnlyField outside of ModelSerializer, but I would call that an uncommon usage pattern. Most of the time I would assume CharField(read_only=True) is more appropriate as ReadOnlyField is in fact made for accessing the models. Nonetheless if it works for DRF, we must handle the case.

@Chadys I added a check to prevent the exception and warn on the situation. Warning resolution via decoration however is not that easy here. I would suggest following the new warning advice 😄

[Chadys]

For anyone stumbling on the exact same issue as me, where I customize rest_framework_simplejwt’s serializers and that makes drf-spectacular crash on ReadOnlyField, the simpler and cleaner way to resolve this is:

class YourCustomTokenObtainPairSerializerExtension(TokenObtainPairSerializerExtension):
    target_class = "your_app_name.serializers.YourCustomTokenObtainPairSerializer"

class YourCustomTokenRefreshSerializerExtension(TokenRefreshSerializerExtension):
    target_class = "your_app_name.serializers.YourCustomTokenRefreshSerializer"

But I still advocate for at least a better error message since that doesn’t seem like a serializer’s misusage to me 😄