django rest框架序列化器和django表单

Question

问题:如何在表单和序列化器中编写用于字段验证的DRY代码？

示例:我有简单的django应用程序与模型形式,它验证passengers字段为Order:

def clean_passengers(self):
    passengers = self.cleaned_data['passengers']
    if passengers > self.flight.available_seats:
        raise forms.ValidationError(
            _(u'''Passengers count can`t be greater then seats count'''))
    return passengers

和Order串行器中的验证相同的代码:

def validate_passengers(self, attrs, source):
    passengers = attrs[source]
    if passengers > self.flight.available_seats:
        raise serializers.ValidationError(
            _(u'''Passengers count can`t be greater then seats count'''))
    return attrs

这不是干的,我写了两次相同的逻辑.我怎么能避免这个？也许我可以从表单或类似的东西继承序列化程序.

Answer 1

您可以使用序列化程序反序列化并验证is_valid表单方法中的数据.

class MyModelForm(ModelForm):
    def is_valid(self):
        # Call super's is_valid to populate cleaned_data and do basic field validation
        valid = super(MyModelForm, self).is_valid()
        if not valid:
            return False

        serializer = MyModelSerializer(data=self.cleaned_data)
        return serializer.is_valid()

Answer 2

这是我对模型表单的可重用验证类的实现。除了重写的get_serializer方法之外，所有原生的 Django 东西都在这里。使用 Django 1.8.13 验证工作状态。

class RestFrameworkValidationModelForm(forms.ModelForm):
    serializer_class = None

    def get_serializer(self, *args, **kwargs):
        """
        Return the serializer instance that should be used for validating and
        deserializing input, and for serializing output.
        """
        assert self.serializer_class is not None, (
            "'%s' should either include a `serializer_class` attribute, "
            "or override the `get_serializer()` method."
            % self.__class__.__name__
        )

        return self.serializer_class(*args, **kwargs)

    def is_valid(self):
        if super(RestFrameworkValidationModelForm, self).is_valid():
            serializer = self.get_serializer(data=self.cleaned_data)
            valid = serializer.is_valid()
            self.add_error(None, serializer.errors)
            return valid
        return False

这是使用示例：

class ExperimentForm(RestFrameworkValidationModelForm):
    serializer_class = ExperimentSerializer

    class Meta:
        model = Experiment
        exclude = []