Django Rest框架: Limit number of fields while using serialzer as nested object

Question

我的代码中的序列化器在两个不同的地方使用。

首次使用:直接

    class FirstSerializer(serializers.ModelSerializer):
        class Meta(object):
            model = FirstSerializer
            fields = ('first_name', 'last_name', 'line1', 'line2',)

第二次使用:在另一个序列化器中

    class SecondSerializer(serializers.ModelSerializer):
        first_serilizer = FirstSerializer(many=True, read_only=True)
    class Meta(object):
        model = SecondSerializer

• 在第一个用例中，我需要所有字段。
• 在第二个用例中，在将其用作嵌套对象时，我想从字段列表中排除“line2”。

Answer 1

我将对“FirstSerializer”类进行子类化，以限制代码重复，并仅指定“PartialFirstSerializer”上所需的字段，

class FirstSerializer(serializers.ModelSerializer):

     class Meta:
        model = FirstModel

class PartialFirstSerializer(FirstSerializer):

    class Meta:
        fields = ('first_name', 'last_name', 'line1')

class SecondSerializer(serializers.ModelSerializer):
    first_serializer = PartialFirstSerializer(many=True, read_only=True)

    class Meta:
        model = SecondModel

如果您正在寻找更通用的解决方案，DRF 文档将向您展示如何创建采用 fields 属性的 DynamicFieldsModelSerializer。 http://www.django-rest-framework.org/api-guide/serializers/#dynamically-modifying-fields

class DynamicFieldsModelSerializer(serializers.ModelSerializer):
    """
    A ModelSerializer that takes an additional `fields` argument that
    controls which fields should be displayed.
    """

    def __init__(self, *args, **kwargs):
        # Don't pass the 'fields' arg up to the superclass
        fields = kwargs.pop('fields', None)

        # Instantiate the superclass normally
        super(DynamicFieldsModelSerializer, self).__init__(*args, **kwargs)

        if fields is not None:
           # Drop any fields that are not specified in the `fields` argument.
           allowed = set(fields)
           existing = set(self.fields.keys())
           for field_name in existing - allowed:
               self.fields.pop(field_name)

class FirstSerializer(DynamicFieldsModelSerializer):

     class Meta:
        model = FirstModel

class SecondSerializer(serializers.ModelSerializer):
    first_serializer = FirstSerializer(fields=('first_name', 'last_name', 'line1'), many=True, read_only=True)

    class Meta:
        model = SecondModel