drf-spectacular: Specify empty payload using @extend_schema

Question

Consider that I have a simple view as,

# serializers.py
class EmptyPayloadResponseSerializer(serializers.Serializer):
    detail = serializers.CharField()


# views.py
from rest_framework.views import APIView
from rest_framework.response import Response
from drf_spectacular.utils import extend_schema
from .serializers import EmptyPayloadResponseSerializer


class EmptyPayloadAPI(APIView):
    @extend_schema(responses=EmptyPayloadResponseSerializer)
    def post(self, request, *args, **kwargs):
        # some actions
        return Response(data={"detail": "Success"})

When I render the schema, I have got the following error response,

Error #0: EmptyPayloadAPI: unable to guess serializer. This is graceful fallback handling for APIViews. Consider using GenericAPIView as view base class, if view is under your control. Ignoring view for now.

So, how can I tell to @extend_schema decorator that I'm intended to pass nothing as payload?

score 6 · Accepted Answer · answered May 22 '21 at 12:09

6

Settings request=None in the @extend_schema(...) decorator will do the trick!!!

class EmptyPayloadAPI(APIView):
    @extend_schema(request=None, responses=EmptyPayloadResponseSerializer)
    def post(self, request, *args, **kwargs):
        # some actions
        return Response(data={"detail": "Success"})

answered May 22 '21 at 12:09

JPG

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While valid, this could cause issues with auto-generated clients. Setting `request=None` will remove the `requestBody` section from the schema. My auto-generated Java `openapi-generator/5.4.0` client failed because it expected `Content-Type` to be defined inside the `requestBody` section on all `POST/PUT/PATCH` requests. – Panos Argyrakis Feb 08 '22 at 22:44
Have you tried to use the [native swagger engine](https://editor.swagger.io/) to build the UI from the specification? and does that have the problem you've mentioned? – JPG Feb 09 '22 at 03:12
Creating the client with `swagger-codegen/3.0.33` failed to build similar to [this issue](https://github.com/swagger-api/swagger-codegen/issues/10580). – Panos Argyrakis Feb 09 '22 at 21:14

drf-spectacular: Specify empty payload using @extend_schema

1 Answers1