使用DRF序列化程序验证字典列表

Question

我该如何编写验证字典列表的序列化程序？

发送的有效负载样本为：

"payment_discount": [
    {
        "discount_rule_id": 1,
        "discount_rule_name": "10 day early payment",
        "discount_earned": "298.00"
    },
    {
        "discount_rule_id": 2,
        "discount_rule_name": "Store discount",
        "discount_earned": "5.50"
    },
]

从这个答案和这个：

class PaymentDiscountSerializer(serializers.DictField):

    discount_rule_id = serializers.IntegerField(required=False)
    discount_rule_name = serializers.CharField(max_length=50)
    discount_earned = serializers.DecimalField(max_digits=10, decimal_places=3)

class PaymentDiscountListSerializer(serializers.ListField):
    """Serialize discount object"""
    child = PaymentDiscountSerializer()

class PaymentSerializer(serializers.ModelSerializer):
    payment_discount = PaymentDiscountListSerializer()
    # Other model fields

这样，我可以使用serializer.data来访问有效负载中的payment_discount对象，但是不幸的是，如果例如有效负载包括非十进制类型的Discount_earned值，则不会对字典进行验证

使用：Django == 1.10.2＆djangorestframework == 3.5.1

Answer 1

我认为您可以简化序列化器...尚未测试过，但可以使用以下方法：

class PaymentDiscountSerializer(serializers.Serializer):
    """Serialize discounts"""
    discount_rule_id = serializers.IntegerField(required=False)
    discount_rule_name = serializers.CharField(max_length=50)
    discount_earned = serializers.DecimalField(max_digits=10, decimal_places=3)

class PaymentSerializer(serializers.ModelSerializer):
    payment_discount = PaymentDiscountSerializer(many=True)
    # Other model fields

它应该为您提供所需的对象列表。

为了进行验证，它应该像这样开箱即用。

但是，我还没有测试过。如果验证存在问题，则可以定义自己的验证。例：

class PaymentDiscountSerializer(serializers.Serializer):
    """Serialize discounts"""
    discount_rule_id = serializers.IntegerField(required=False)
    discount_rule_name = serializers.CharField(max_length=50)
    discount_earned = serializers.DecimalField(max_digits=10, decimal_places=3)

    def validate_discount_rule_id(self, value):
        # Validation logic of the discount_rule_id field
        #
        return value

    def validate(self, attrs):
        # Validation logic of all the fields
        #
        return attrs

有关更多信息，请参见http://www.django-rest-framework.org/api-guide/serializers/#field-level-validation。