基于 Django 类的 View : Posting form data returns 302 Found status code

Question

我正在使用 django 的基于通用类的 View CreateView 将图像上传到书中。代码如下:

# models.py
class Upload(models.Model):
    image = models.ImageField(upload_to=get_upload_path, help_text='Image to process')
    uploader = models.ForeignKey(settings.AUTH_USER_MODEL, models.CASCADE, related_name='uploader')
    language = models.ForeignKey(Language, models.CASCADE)
    book = models.ForeignKey(Book, models.CASCADE)

    def __str__(self):
        return str(os.path.split(self.image.name)[-1].split('_', 1)[-1])

    @models.permalink
    def get_absolute_url(self):
        return ('book:upload_new', (self.book.id,))     # upload_new is linked to the view below

    def save(self, *args, **kwargs):
        super(Upload, self).save(*args, **kwargs)

    def delete(self, *args, **kwargs):
        self.image.delete(False)
        super(Upload, self).delete(*args, **kwargs)


# views.py
@method_decorator(login_required, name='dispatch')
class PictureCreateView(CreateView):
    model = Upload
    fields = ("image",)
    book_id = None

    def dispatch(self, *args, **kwargs):
        # book_id is passed as a URL parameter
        self.book_id = self.kwargs['book_id']
        return super().dispatch(*args, **kwargs)

    def get_context_data(self, **kwargs):
        context = super(PictureCreateView, self).get_context_data(**kwargs)
        context['book_id'] = self.book_id
        return context

    def form_valid(self, form, **kwargs):
        book = Book.objects.get(id=self.book_id)
        form.instance.book = book
        form.instance.language = book.language
        form.instance.uploader = self.request.user
        self.object = form.save()

        # Running the command below prints
        # <TemplateResponse status_code=200, "text/html; charset=utf-8">
        # implying the upload was successful
        #
        # print(self.render_to_response(context=self.get_context_data()))

        return super(PictureCreateView, self).form_valid(form)

    def form_invalid(self, form):
        print(form.errors)
        data = json.dumps(form.errors)
        return HttpResponse(content=data, status=400, content_type='application/json')

当我尝试上传图像时，我收到此请求的 302 Found 错误(如我的浏览器的开发工具中所示)，这意味着页面已暂时移动。除了 header 之外，我无法看到此请求的预览或响应。不过上传成功了(我检查了管理页面)。

有人有 this issue之前，答案指出了 URL conf 中的错误。但是，问题并未完全解决，OP 仍然收到 302 状态代码。

这可能是什么原因？

Answer 1

默认情况下，form_valid 方法使用 302 代码重定向到 success_url(可以通过重写 get_success_url 动态生成)。所以这是正常行为，我认为这是一个很好的做法。所以我不会改变它。

但是如果您确实愿意，您可以返回任何其他响应代码，例如:与 get 内容类似的 200 代码

# views.py
@method_decorator(login_required, name='dispatch')
class PictureCreateView(CreateView):
    ...

    def form_valid(self, form, **kwargs):
        book = Book.objects.get(id=self.book_id)
        form.instance.book = book
        form.instance.language = book.language
        form.instance.uploader = self.request.user
        self.object = form.save()

        context = self.get_context_data()
        # You may have check and modify your context for a correct page
        # May be: add new things
        context["success"] = True

        return self.render_to_response(context))