Django REST框架自定义字段验证 [英] Django REST Framework custom fields validation

问题描述

我正在尝试为模型创建自定义验证，以检查其 start_date 是否在其 end_date 之前，

I am trying to create custom validation for a model, to check that its start_date is before its end_date and it is proving near impossible.

我尝试过的东西：

• 内置的Django验证器：没有检查这个

• built-in Django validators: none check for this

写我自己的，像这样：

def validate_date(self):
   if self.start_date < self.end_date:
        raise serializers.ValidationError("End date must be after start date.")

我已经添加到Serializer类（然后是模型）的代码位，但似乎没有在任一位置调用。

That bit of code I have added to the Serializer class (and then the model), but it does not seem to get called in either location.

我还发现这个

I also found this bit of code that might be of use, but I don't know how to integrate in my method- it seems that it would work to validate one model attribute, but I need to check between two attributes.

我的模型：

class MyModel(models.Model):

    created = models.DateTimeField(auto_now_add=True)
    relation_model = models.ForeignKey(RelationModel, related_name="mymodels")
    priority = models.IntegerField(
        validators = [validators.MinValueValidator(0), validators.MaxValueValidator(100)])
    start_date = models.DateField()
end_date = models.DateField()

    @property
    def is_active(self):
        today = datetime.date.today()
        return (today >= self.start_date) and (today <= self.end_date)

    def __unicode__(self):
        ...

    class Meta:
        unique_together = ('relation_model', 'priority', 'start_date', 'end_date')

Fyi，所有其他验证工作！

Fyi, all the other validations work!

我的序列化器：

class MyModelSerializer(serializers.ModelSerializer):

    relation_model = RelationModelSerializer
    is_active = serializers.Field(source='is_active')

    def validate_date(self):
        if self.start_date > self.end_date:
            raise serializers.ValidationError("End date must be after start date.")   

    class Meta:
        model = MyModel
        fields = (
            'id', 'relation_model', 'priority', 'start_date', 'end_date', 'is_active'
        )

我的观点：

class MyModelList(generics.ListCreateAPIView):
    permission_classes = (IsAdminUser,)
    queryset = MyModel.objects.all()
    serializer_class = MyModelSerializer
    ordering = ('priority')

推荐答案

您应该使用对象广泛验证（ validate（））因为 validate_date 将永远不会被调用，因为 date 不是序列化程序中的一个字段。 从文档：

You should use an object wide validation (validate()), since validate_date will never be called since date is not a field on the serializer. From the documentation:

class MySerializer(serializers.ModelSerializer):
    def validate(self, data):
        """
        Check that the start is before the stop.
        """
        if data['start_date'] > data['end_date']:
            raise serializers.ValidationError("finish must occur after start")
        return data

您还可以在模型上添加一个干净的方法：

You could also add a clean method on the model:

class MyModel(models.Model):
    start_date = models.DateField()
    end_date = models.DateField()
    def clean(self):
        if self.end_date < self.start_date:
            raise ValidationError("End date must be after start date.")

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