Django DRF 将 request.user 添加到模型序列化器

Question

我正在使用 django rest 框架，并且我有一个通过模型 View 集和模型序列化器创建的对象。此 View 只能由经过身份验证的用户访问，并且对象应将其“uploaded_by”字段设置为该用户。

我已经阅读了文档，并得出结论，这应该可行

View 集:

class FooViewset(viewsets.ModelViewSet):
    permission_classes = [permissions.IsAdminUser]
    queryset = Foo.objects.all()
    serializer_class = FooSerializer

    def get_serializer_context(self):
        return {"request": self.request}

序列化器:

class FooSerializer(serializers.ModelSerializer):
    uploaded_by = serializers.PrimaryKeyRelatedField(
        read_only=True, default=serializers.CurrentUserDefault()
    )

    class Meta:
        model = Foo
        fields = "__all__"

但是，这会导致以下错误:

django.db.utils.IntegrityError: NOT NULL constraint failed: bar_foo.uploaded_by_id

这表明“uploaded_by”没有被序列化程序填充。

根据我对文档的理解，这应该已将该字段添加到来自序列化程序的验证数据中，作为 create 方法的一部分。

显然我误解了一些东西!

Answer 1

问题出在read_only您的 uploaded_by 上的属性 field :

Read-only fields are included in the API output, but should not be included in the input during create or update operations. Any 'read_only' fields that are incorrectly included in the serializer input will be ignored.

Set this to True to ensure that the field is used when serializing a representation, but is not used when creating or updating an instance during deserialization.

Source

基本上它用于显示对象的表示，但不包括在任何更新和创建过程中。

相反，您可以覆盖 create通过手动分配来存储所需用户的功能。

class FooSerializer(serializers.ModelSerializer):

    uploaded_by = serializers.PrimaryKeyRelatedField(read_only=True)

    def create(self, validated_data):
        foo = Foo.objects.create(uploaded_by=self.context['request'].user,
                                 **validated_data)
        return foo