验证数据字段不同于数据字段 Django Rest 嵌套序列化程序

Question

所以我在 django 中使用序列化器并想在我的响应中更改我的字段的名称，当我意识到我的更改没有被计算在内时我做了一些挖掘并看到我的 validated_data与我的数据不同。

我的目标是将 python 对象提供给序列化程序，该序列化程序的字段与我想要 return 的名称不同，因此我在我的字段中使用了 'source=' 参数。

请注意，更改 python 对象字段的名称不是一个选项。

这是 python 对象：

class Flow(object):
    """Just a regular python object"""
    def __init__(self, name=None, flow_uid=None, data_type=None, parent=None, container=None):
        """This has more fields than the serializer is waiting"""
        self._parent = None
        self._container = None
        self.name = name
        self.data_type = data_type
        self.flow_uid = flow_uid

以及以下序列化程序（我使用的是嵌套表示）
serializers.py

from rest_framework.fields import CharField, IntegerField, ListField, JSONField
from rest_framework.serializers import Serializer

class OutputSerializer(Serializer):
    uid = CharField(max_length=36)
    name = CharField(max_length=100)
    description = CharField(max_length=100)


class FlowSerializer(Serializer):
    uid = CharField(source='flow_uid', max_length=36) # I want 'uid' in my response not 'flow_uid'
    name = CharField(max_length=100)
    data_type = CharField(max_length=100)
    class Meta:
        fields = '___all___'

    def to_representation(self, instance):
        instance = super(FlowSerializer, self).to_representation(instance)
        #Here instance = OrderedDict([('uid', 'uid_value'), ('name', 'name_value'), ('data_type', 'data_value')])
        return instance


class FlowOutputSerializer(OutputSerializer):
    columns = FlowSerializer(many=True)

viewsets.py

class AddTransformationViewSet(ViewSet):
    """Handle available "actions" for BrickModel operations"""

    def list(self, request, parent_lookup_analyses: str):
        """The method I call for this test"""

        flow1 = Flow(name="name1", flow_uid='flow_uid_value1', data_type='str')
        flow2 = Flow(name="name2", flow_uid='flow_uid_value2', data_type='str')
        flow1_ser = FlowSerializer(flow1)
        flow2_ser = FlowSerializer(flow2)

        dummy_col = {
            "name": "output_name",
            "description": "output_description",
            "uid": "output_uid",
            "columns":
            [
                flow2_ser.data, # Debug: {'uid': 'flow_uid_value2', 'name': 'name2', 'data_type': 'str'}
                flow1_ser.data # Debug: {'uid': 'flow_uid_value1', 'name': 'name1', 'data_type': 'str'}
            ]
        }
        #Debug dummy_col: {'name': 'output_name', 'description': 'output_description', 'uid': 'output_uid', 'columns': [{'uid': 'flow_uid_value2', 'name': 'name2', 'data_type': 'str'}, {'uid': 'flow_uid_value1', 'name': 'name1', 'data_type': 'str'}]} 


        dummy_serializer: FlowOutputSerializer = FlowOutputSerializer(data=dummy_col)
        dummy_serializer.is_valid(raise_exception=True)
        # Debug dummy_serializer.data: {'uid': 'output_uid', 'name': 'output_name', 'description': 'output_description', 'columns': [OrderedDict([('uid', 'flow_uid_value2'), ('name', 'name2'), ('data_type', 'str')]), OrderedDict([('uid', 'flow_uid_value1'), ('name', 'name1'), ('data_type', 'str')])]}
        # Debug dummy_serializer.validated_data: OrderedDict([('uid', 'output_uid'), ('name', 'output_name'), ('description', 'output_description'), ('columns', [OrderedDict([('flow_uid', 'flow_uid_value2'), ('name', 'name2'), ('data_type', 'str')]), OrderedDict([('flow_uid', 'flow_uid_value1'), ('name', 'name1'), ('data_type', 'str')])])])
        return Response(data=dummy_serializer.validated_data, status=status.HTTP_201_CREATED)

Expected_response:

{
    ...
    "columns": [
        {
            "uid": "flow_uid_value2",
            "name": "name2",
            "data_type": "str"
        },
        {
            "uid": "flow_uid_value1",
            "name": "name1",
            "data_type": "str"
        }
    ]
}

我得到的（我希望 'flow_uid' 成为 'uid'）：

{
    ...
    "columns": [
        {
            "flow_uid": "flow_uid_value2",
            "name": "name2",
            "data_type": "str"
        },
        {
            "flow_uid": "flow_uid_value1",
            "name": "name1",
            "data_type": "str"
        }
    ]
}

在这种情况下使用 .data 而不是 .validated_data 是否有任何特别的危险？这种行为的原因是什么？

Answer 1

Is there any particular danger in using .data in this case rather than .validated_data? What is the cause of this behavior?

serializer.validated_data 旨在与 Python 对象一起使用。因此，由于自定义 source 值，它将公开 flow_uid。

serializer.data 将是 save() 在 save 被调用后的序列化结果。

因此，您应该在您的回复中始终使用serializer.data，并在与模型或内部项目代码交互的任何代码中保留serializer.validated_data：

Response(data=dummy_serializer.data, status=status.HTTP_201_CREATED)

验证数据字段不同于数据字段 Django Rest 嵌套序列化程序

Validated data fields differs from data fields Django Rest Nested serializers

python

django

json

django-serializer

django-rest-framework