django - 如果在 Django 表单中选中另一个字段，则将字段设为必需

Question

我有一个这样的模型:

class News(models.Model):
    is_activity = models.BooleanField(default=False)
    activity_name = models.CharField(max_length=240, blank=True, null=True)

我想要实现的是，如果 is_activity已入住 我要 activity_name被要求。因此，我试图覆盖 __init__方法:

class NewsForm(forms.ModelForm):
    class Meta:
        model = News

    def __init__(self, *args, **kwargs):
        super(NewsForm, self).__init__(*args, **kwargs)
        if self.fields['is_activity'] is True:
            self.fields['activity_name'].required = True


class NewsAdmin(FrontendEditableAdminMixin, admin.ModelAdmin):
    form = NewsForm

即使我 checkin is_activity activity_name是非必需的。怎么了？

Answer 1

ModelForm.clean()方法使您可以访问清理过的数据——您可以在此处包含特定于字段的条件逻辑:

from django.core.validators import EMPTY_VALUES

class NewsForm(forms.ModelForm):
    class Meta:
        model = News

    def clean(self):
        is_activity = self.cleaned_data.get('is_activity', False)
        if is_activity:
            # validate the activity name
            activity_name = self.cleaned_data.get('activity_name', None)
            if activity_name in EMPTY_VALUES:
                self._errors['activity_name'] = self.error_class([
                    'Activity message required here'])
        return self.cleaned_data

class NewsAdmin(FrontendEditableAdminMixin, admin.ModelAdmin):
    form = NewsForm