example_viewset.py

from rest_framework import viewsets, status
from rest_framework.decorators import action
from rest_framework.response import Response
from rest_framework.request import Request

from example_app.models import Example
from example_app.serializers import ExampleSerializer, ExampleUploadURLSerializer
from example_app.s3_files import get_presigned_url_dict_to_upload_file


class ExampleViewSet(viewsets.ModelViewSet):
   serializer_class = ExampleSerializer
   queryset = Example.objects.all()

   @action(detail=False, methods=('post',), url_path='upload-url')
   def upload_url(self, request: Request) -> Response:
       serializer = ExampleUploadURLSerializer(data=request.data)
       serializer.is_valid(raise_exception=True)

       object_key = serializer.validated_data['object_key']

       upload_url_dict = get_presigned_url_dict_to_upload_file(object_key)

       return_serializer = ExampleUploadURLSerializer(
           data={'object_key': object_key, 'upload_url_dict': upload_url_dict,}
       )
       return_serializer.is_valid(raise_exception=True)

       return Response(return_serializer.validated_data, status=status.HTTP_200_OK)