如何使用 DetailView 在 Django 上获取 POST 和创建消息

Question

我有 Post model 和 Message model。

我想获取 POST，在一个帖子上创建消息并进行预览。

我有ValueError Cannot assign "<bound method PostDetailView.post of <blog.views.PostDetailView object at 0x7fa9a370b8>>": "Message.post" must be a "Post" instance. 在body = request.POST.get('body')

我怎样才能做到这一点？

我所有的代码

模型.py

class Post(models.Model):
    title = models.CharField(max_length=100)
    content = models.TextField()
    date_posted = models.DateTimeField(auto_now_add=True)
    author = models.ForeignKey(User,on_delete=models.CASCADE)
    topic = models.ForeignKey(Topic,on_delete=models.SET_NULL,null=True)

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse('post-detail',kwargs={'pk':self.pk})


class Message(models.Model):
    user = models.ForeignKey(User,on_delete=models.CASCADE) 
    post = models.ForeignKey(Post,on_delete=models.CASCADE)
    body = models.TextField()
    date_posted = models.DateTimeField(auto_now_add=True)

    def __str__(self):
        return self.body[0:50]

视图.py

class PostDetailView(DetailView):
    model = Post

    def post(self, request, *args, **kwargs):
        message = Message(
            user = request.user,
            post = self.post,
            body = request.POST.get('body')
        )
        message.save()
        return super(PostDetailView,self).post(request, *args, **kwargs)

网址.py

urlpatterns = [
 path('post/<int:pk>',PostDetailView.as_view(),name='post-detail')
]

Answer 1

假设您的 url 具有post_id参数，如https://example.com/?post_id=1 ：

def get_post(post_id):
    try:
        post = Post.objects.get(id=post_id)
    except Post.DoesNotExist:
        raise ValidationError(f"Post model with id {post_id} was not found.")

def post(self, request, *args, **kwargs):
        message = Message(
            user = request.user,
            post = self.get_post(kwargs.get('pk')),
            body = request.POST.get('body')
        )
        message.save()
        return super(PostDetailView,self).post(request, *args, **kwargs)

这应该让你去。 不过，我强烈建议设置一个序列化程序来验证您的查询参数。

class ParamValidationSerializer(serializers.Serializer):
    post_id = serializers.IntegerField()

然后将您的帖子 function 更改为：

def post(self, request, *args, **kwargs):
    serializer = ParamValidationSerializer(data={'post_id': kwargs.get('pk')})
    serializer.is_valid(raise_exception=True)
    message = Message(
        user = request.user,
        post = self.get_post(serializer.data.get('post_id')),
        body = request.POST.get('body')
    )
    message.save()
    return super(PostDetailView,self).post(request, *args, **kwargs)