在 django-admin 内联表单上验证删除答案

【问题标题】：Validating delete on django-admin inline forms在 django-admin 内联表单上验证删除
【发布时间】：2011-05-17 07:21:18
【问题描述】：

我正在尝试执行验证，如果用户是管理员，您将无法删除他。因此，如果有管理员用户被标记为删除，我想检查并提出错误。

这是我的内联ModelForm

class UserGroupsForm(forms.ModelForm):
    class Meta:
        model = UserGroups

    def clean(self):
        delete_checked = self.fields['DELETE'].widget.value_from_datadict(
            self.data, self.files, self.add_prefix('DELETE'))
        if bool(delete_checked):
            #if user is admin of group x
            raise forms.ValidationError('You cannot delete a user that is the group administrator')

        return self.cleaned_data

if bool(delete_checked): 条件返回 true，if 块内的内容被执行，但由于某种原因，从未引发此验证错误。有人可以解释一下为什么吗？

如果有其他更好的方法可以做到这一点，请告诉我

【问题讨论】：

标签： django validation django-admin django-forms

【解决方案1】：

我找到的解决方案是在InlineFormSet 中使用clean 而不是ModelForm

class UserGroupsInlineFormset(forms.models.BaseInlineFormSet):

    def clean(self):
        delete_checked = False

        for form in self.forms:
            try:
                if form.cleaned_data:
                    if form.cleaned_data['DELETE']:
                        delete_checked = True

            except AttributeError:
                pass

        if delete_checked:
            raise forms.ValidationError(u'You cannot delete a user that is the group administrator')

【讨论】：

【解决方案2】：

虽然@domino 的答案现在可能有效，但“有点”recommended approach 是将formset 的self._should_delete_form(form) 函数与self.can_delete 一起使用。

还有调用super().clean() 来执行标准内置验证的问题。所以最终的代码可能是这样的：

class UserGroupsInlineFormset(forms.models.BaseInlineFormSet):
    def clean(self):
        super().clean()
        if any(self.errors):
            return  # Don't bother validating the formset unless each form is valid on its own
        for form in self.forms:
            if self.can_delete and self._should_delete_form(form):
                if <...form.instance.is_admin...>:
                    raise ValidationError('...')

【讨论】：

【解决方案3】：

添加到多米诺骨牌的答案：

在其他一些场景中，有时用户想同时删除和添加对象，所以在这种情况下删除应该没问题！

优化版代码：

class RequiredImageInlineFormset(forms.models.BaseInlineFormSet):
    """ Makes inline fields required """

    def clean(self):
        # get forms that actually have valid data
        count = 0
        delete_checked = 0
        for form in self.forms:
            try:
                if form.cleaned_data:
                    count += 1
                    if form.cleaned_data['DELETE']:
                        delete_checked += 1
                    if not form.cleaned_data['DELETE']:
                        delete_checked -= 1
            except AttributeError:
                # annoyingly, if a subform is invalid Django explicity raises
                # an AttributeError for cleaned_data
                pass

        # Case no images uploaded
        if count < 1:
            raise forms.ValidationError(
                'At least one image is required.')

        # Case one image added and another deleted
        if delete_checked > 0 and ProductImage.objects.filter(product=self.instance).count() == 1:
            raise forms.ValidationError(
                "At least one image is required.")

【讨论】：