django - 如何将 django 错误验证绑定到特定的 ForeignKey 字段，而不是整个模型

Question

class Business(models.Model):
    is_distributor = models.BooleanField()

class Invoice(models.Model):
    from_business = models.ForeignKey(Business)
    to_business = models.ForeignKey(Business)

要有效，Invoice.from_business.is_distributor 必须为 True。我可以在 clean() 中执行此操作，但此错误与整个模型相关，而不是特定的 from_business 字段。

我也不认为验证器可以与 ForeignKey 字段挂钩。

Answer 1

您可以轻松访问外键字段的实例并使用clean方法验证属性：

from django import forms

from your_app.models import Invoice


class InvoiceForm(forms.ModelForm):
    def clean(self):
        cleaned_data = self.cleaned_data()

        business = cleaned_data.get('business')
        if not business.is_distributor:
            self._errors['business'] = self.error_class(
                ['Business must be a distributor.'])
            del cleaned_data['business']

        return cleaned_data