如何在 Django Rest Framework 的序列化程序中传递字段验证

Question

我有一个 Location 模型，我需要在不指定用户的情况下创建一个 Location，如果用户为空，那么该用户将被放置在视图集中的 request.user 中。

这是我的模型：

class Location(models.Model):
    user = models.ForeignKey(User)
    name = models.CharField(max_length=100)

序列化器：

class LocationSerializer(serializers.ModelSerializer):

    def is_valid(self):
        if not 'user' in self.init_data:
            # avoid this validation.. I manage this in the viewset
            pass

        return not self.errors

    class Meta:
        model = Location

和视图集

class LocationViewSet(ModelViewSet):
    """
    API endpoint that allows location to be created or viewed.
    """
    model = Location
    serializer_class = LocationSerializer
    renderer_classes = (JSONRenderer, JSONPRenderer)

    def get_queryset(self):
        return self.request.user.locations.filter(deleted=False)

    def create(self, request, *args, **kwargs):
        serializer = self.get_serializer(data=request.DATA, files=request.FILES)

        if serializer.is_valid():
            self.pre_save(serializer.object)
            if not self.object.user:
                self.object.user = request.user
            self.object = serializer.save(force_insert=True)
            self.post_save(self.object, created=True)
            headers = self.get_success_headers(serializer.data)
            return Response(serializer.data, status=status.HTTP_201_CREATED,
                            headers=headers)

感谢您的建议

Answer 1

您可以在序列化程序中使用required=False：

class LocationSerializer(serializers.ModelSerializer):
    user = serializers.RelatedField(required=False)

编辑

您还可以通过以下方式简化视图集：

class LocationViewSet(ModelViewSet):
    def pre_save(self, obj):
        if obj.user_id is None:
            obj.user = self.request.user

这避免了从 DRF 核心复制代码。