django - 在 Django Rest Framework 中，如何处理无效的过滤参数？

Question

我想限制 ListAPIView 返回的查询集，使用描述的过滤技术 here .

问题是，如何处理无效参数？引发 ValidationError 仅适用于序列化程序，不适用于 ViewSet。我想让用户知道请求无效，而不是默默地失败。

例如:

class PurchaseList(generics.ListAPIView):
    serializer_class = PurchaseSerializer

    def get_queryset(self):
        queryset = Purchase.objects.all()
        username = self.request.query_params.get('username', None)
        if username is not None:
              try:
                  user = User.objects.get(username=username)
              except User.DoesNotExist:
                  # How do I handle this invalid parameter?
              else:
                  queryset = queryset.filter(purchaser=user)
        return queryset

Answer 1

使用内置异常，因为您正在响应未找到的内容，请使用 NotFound:

from rest_framework import exceptions

class PurchaseList(generics.ListAPIView):
    serializer_class = PurchaseSerializer

    def get_queryset(self):
        queryset = Purchase.objects.all()
        username = self.request.query_params.get('username', None)
        if username is not None:
              try:
                  user = User.objects.get(username=username)
              except User.DoesNotExist:
                  raise exceptions.NotFound(detail="Some message if you want")
              else:
                  return queryset.filter(purchaser=user)
        return queryset