python - Django - 内联表单集验证

Question

我正在尝试验证我的内联表单集成本值，以确保它加起来等于 100。表单集返回 5 次，因此应该为每个值添加值，直到达到 100。如果它大于或小于显示错误并且不允许用户点击创建按钮。我正在尝试验证所有表单的组合，而不是每个表单值。

模型.py

class EstimatedBudgetForm(forms.ModelForm):
def clean(self):
    # get forms that actually have valid data
    count = 0
    for percentage in self.cost:
        try:
            if percentage.cleaned_data:
                count += percentage
        except AttributeError:
            # annoyingly, if a subform is invalid Django explicity raises
            # an AttributeError for cleaned_data
            pass
    if count != 100:
        raise forms.ValidationError('Percentage must equal 100%')

Views.py

EstimatedBudgetChildFormset = inlineformset_factory(
  Project, EstimatedBudget, fields=('project', 'item', 'cost', 'time'), can_delete=False, form=EstimatedBudgetForm, extra=5, widgets={'item': forms.Select(attrs={'disabled': True})},
)

Answer 1

要对表单集执行验证，应该覆盖表单集(而非表单)的 clean 方法。对于内联表单集，您需要继承 BaseInlineFormSet 并使用它(有关更多信息，请参阅 Overriding clean() on a ModelFormSet [Django docs] ):

from django.forms import BaseInlineFormSet


class MyInlineFormset(BaseInlineFormSet):
    def clean(self):
        super().clean()
        count = 0
        for form in self.forms:
            if not form.errors: # No need for a try-except, just check if the form doesn't have errors
                count += form.cleaned_data['cost']
        if count != 100: # This condition might not work if you are dealing with floating point numbers
            raise forms.ValidationError('Percentage must equal 100%')

接下来在制作表单集时，指定 formset kwarg 而不是 form:

EstimatedBudgetChildFormset = inlineformset_factory(
  Project, EstimatedBudget, fields=('project', 'item', 'cost', 'time'), can_delete=False, formset=MyInlineFormset, extra=5, widgets={'item': forms.Select(attrs={'disabled': True})},
)