如何从 Django DeleteView 发送错误消息？

Question

假设有两个模型 Parent 和 Child。 Parent 到 child 是一对多关系。

我正在为父模型创建 DeleteView。在删除之前我需要检查 Parent 是否有 Children。如果没有 Children，那么 Parent 模型将照常删除。但是如果有 Children 那么我需要发送错误消息到 DeleteView 确认页面。

如何使用 DeleteView 实现此目的？

Answer 1

您可以覆盖 delete 方法并使用 Django's message framework

设置消息

from django.contrib import messages

class DeletePArent(DeleteView):

   # ...

   def delete(self, request, *args, **args):
       object = self.get_object()
       if object.chidlren.count() > 0:
           messages.add_message(request, messages.ERROR, "Can't be deleted, has childern")
           return redirect('url-of-your-choice')
       return super().delete(request, *args, **kwargs)

Answer 2

DeleteView继承DeletionMixin. What you can do is add on_delete=PROTECTED in your child model and override the delete method in your view to catch a ProtectedError exception. For the error message, see Django's message framework.

models.py:

class Child():
    #...
    myParent = models.ForeignKey(Parent, on_delete=PROTECTED)

views.py:

from django.db.models import ProtectedError

#...

class ParentDelete(DeleteView):
    #...
    def delete(self, request, *args, **kwargs):
        """
        Call the delete() method on the fetched object and then redirect to the
        success URL. If the object is protected, send an error message.
        """
        self.object = self.get_object()
        success_url = self.get_success_url()

        try:
            self.object.delete()
        except ProtectedError:
            messages.add_message(request, messages.ERROR, 'Can not delete: this parent has a child!')
            return # The url of the delete view (or whatever you want)

        return HttpResponseRedirect(success_url)

如何从 Django DeleteView 发送错误消息？

How to send error message from Django DeleteView?

django

django-views

django-class-based-views