Django 表单验证默认值错误

Question

class CustomerForm(forms.ModelForm):

    class Meta:
        model = Customer


class Customer(models.Model):
    balance = models.FloatField(default = 0.0)

form = CustomerForm(request.POST)
if form.is_valid():
    # is FALSE

当我提交没有 balance 字段的表单时，我收到一条验证错误，指出余额字段是必需的。这是为什么？

Answer 1

您可以帮助将 clean_FIELDNAME 方法添加到默认返回 0.0 的表单中。 该方法在表单清理过程中被调用。

class CustomerForm(forms.ModelForm):
    balance = models.FloatField(required=False)

    def clean_balance(self):
        if not 'balance' in self.cleaned_data or self.cleaned_data['balance'] is None:
            return self._meta.model._meta.get_field('balance').default
        else:
            return self.cleaned_data['balance']

处理此问题的另一种方法是使用表单 clean 方法将余额字段从 clean_data 中剔除，并让模型设置默认值。

class CustomerForm(forms.ModelForm):

    class Meta:
        model = Customer

    def clean(self):
        if 'balance' in self.cleaned_data and self.cleaned_data['balance'] is None:
            del self.cleaned_data['balance']
        return self.cleaned_data


class Customer(models.Model):

    balance = models.FloatField(blank=True, null=False, default=0.0)