验证 django-admin 内联表单上的删除

Question

我正在尝试执行验证，以便您无法删除用户（如果他是管理员）。因此，我想检查是否存在管理员用户并已被标记为删除，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，并且 if 块内的内容被执行，但由于某种原因此验证永远不会引发错误。有人可以向我解释一下为什么吗？

更好的是，如果有其他更好的方法来做到这一点，请告诉我

Answer 1

我找到的解决方案是在 InlineFormSet 而不是 ModelForm 中进行 clean

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')

Answer 2

添加到多米诺骨牌的答案：

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

优化版本代码：

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.")

Answer 3

虽然@domino的答案目前可能有效，但“有点” 推荐的方法是将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如下所示：

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('...')