如何检查表单中两个字段的验证？

Question

需要通过输入图片的链接来向表单添加图片，或上传文件 从您的计算机。 如果在提交表单时未输入任何选项，或同时输入了两个选项，则应显示错误消息。加载成功后，应该会进入图片页面。

models.py：

class Picture(models.Model):
    url = models.URLField(blank=True, verbose_name='Ссылка на изображение')
    image = models.ImageField(upload_to='pictures/%Y/%m/%d', width_field='image_width', height_field='image_height',
                              blank=True, verbose_name='Изображение')
    image_width = models.IntegerField(default=0, blank=True, verbose_name='Ширина изображения')
    image_height = models.IntegerField(default=0, blank=True, verbose_name='Высота изображения')
    is_active = models.BooleanField(default=True, verbose_name='Актуальность изображения')
    created = models.DateField(blank=True, null=True, default=timezone.now, verbose_name='Дата создания записи')
    updated = models.DateField(blank=True, null=True, default=timezone.now, verbose_name='Дата ред-ия записи')

views.py：

def add_picture(request):
    picture = Picture.objects.filter(is_active=True)
    if request.method == 'POST':
        form = PictureCreateForm(data=request.POST, files=request.FILES)
        if form.is_valid():
            form.save()
            return render(request, 'add_picture.html', locals())
        else:
            messages.error(request, 'Ошибка, проверьте данные')
    else:
        form = PictureCreateForm()

    return render(request, 'add_picture.html', locals())

forms.py:这里需要定义一个方法clean

class PictureCreateForm(forms.ModelForm):
    class Meta:
        model = Picture
        fields = ('url', 'image')

def clean(self):

    cd = self.cleaned_data
    if cd['url'] and cd['image']:
        raise forms.ValidationError('Ошибка!')
    if not cd['url'] and not cd['image']:
        raise forms.ValidationError('Ошибка!')
    return cd

urls.py:

urlpatterns = [
    path('', views.home, name='home'),
    path('add_picture/', views.add_picture, name='add_picture'),
    path('picture_detail/<int:id>/', views.picture_detail, name='picture_detail'),
]

Answer 1

你可以利用forms.ModelForm的clean(...)方法作为

class PictureCreateForm(forms.ModelForm):
    class Meta:
        model = Picture
        fields = ('url', 'image')

    def clean(self):
        cleaned_data = super().clean()
        url = cleaned_data.get("url")
        image = cleaned_data.get("url")

        # do your logic here
        # atlast
        return cleaned_data