Question

我正在使用django mptt

以下是我的观点：

    def category(request, path, instance, extra):
        if instance:
            instance.save()

        queryset = Product.objects.filter(category__in=instance.get_descendants(include_self=True))

        color = request.GET.get('q')

        if color:
            queryset = Product.objects.filter(optiongroup__option = color )

        return render(
            request,
            'products/prodgrid.html',
            {
                'instance': instance,
                'children': instance.get_children() if instance else Category.objects.root_nodes(),
                'queryset': queryset,
            }
        )

这是追溯

Traceback:
File "C:\Python27\lib\site-packages\django\core\handlers\base.py" in get_response
  132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\lenovo\Desktop\plump\Plumpin\src\mptt_urls\__init__.py" in __call__
  35.         return self.view(*args, **kwargs)
File "C:\Users\lenovo\Desktop\plump\Plumpin\src\products\views.py" in category
  35.     queryset = Product.objects.filter(category__in=instance.get_descendants(include_self=True))

Exception Type: AttributeError at /category/women/women-clothing/dresses/
Exception Value: 'NoneType' object has no attribute 'get_descendants'

这是模板

{% for color in instance.get_colors %}
                        <li><label for="{{color.value}}"><input type="checkbox" id="{{color.value}}" group = "color"  value="{{ color.value }}"/><a href="{{ instance.get_absolute_url }}/?color={{ color.value }}">{{ color.value }}</a></label></li>
                        {% endfor %}

我在哪里错了？

如何改进代码？

Answer 1

您的代码在此行中失败：

queryset = Product.objects.filter(category__in=instance.get_descendants(include_self=True))

因为实例是None。您需要弄清楚为什么category方法已使用instance=None进行调用。你希望在哪里设置实例？

'NoneType'对象没有属性'get_descendants'

1 个答案: