Django Guardian权限错误:参数pk未传递到视图函数中

Question

我有一个名为Message的模型，我使用django-guardian获得对象级权限。其思想是消息实例中的from_user和to_user都应该具有can_view_message权限。此功能用于显示具有相同消息thread_id（在创建消息时自动创建）的消息列表。

@permission_required_or_403('can_view_message', (Message, 'pk', 'pk'))
def message_thread(request, pk):
    selected_message = Message.objects.get(pk=pk)
    threads = Message.objects.filter(thread_id=selected_message.thread_id)
    context = RequestContext(request, {
        'latest_messages': threads,
    })
    return render(request, 'myapp/messages_thread.html', context)

此请求的url模式：url(r'^messages/([-_a-z0-9]{1,32})/$', message_views.message_thread),

以下是消息模型：

class Message(models.Model):
    from_user = models.ForeignKey(User, verbose_name='From', related_name='%(class)s_from_user')
    to_user = models.ForeignKey(User, verbose_name='To', related_name='%(class)s_to_user')
    send_time = models.DateTimeField('Send Time', blank=True)
    msg_content = models.TextField('Message')
    thread_id = models.CharField('Thread', max_length=50, blank=True)
    class Meta:
        permissions = (
            ('can_view_message', 'Can View Message'),
        )

我使用post_create信号分配权限：

def view_message(sender, instance, **kwargs):
    assign_perm('can_view_message', instance.from_user, instance)
    assign_perm('can_view_message', instance.to_user, instance)
post_save.connect(view_message, sender=Message, dispatch_uid="view_message_permission")

然而，我得到了以下错误，但不知道为什么：

GuardianError at /myapp/messages/13/
Argument pk was not passed into view function
Request Method: GET
Request URL:    http://127.0.0.1:8000/myapp/messages/13/
Django Version: 1.8.4
Exception Type: GuardianError
Exception Value:    
Argument pk was not passed into view function
Exception Location: /Library/Python/2.7/site-packages/guardian/decorators.py in _wrapped_view, line 111
Python Executable:  /usr/bin/python
Python Version: 2.7.6

任何帮助都将不胜感激，非常感谢！

Answer 1

根据@Burhan Khalid的评论，我检查了我的请求url，它是url(r'^messages/([-_a-z0-9]{1,32})/$', message_views.message_thread),

我把它改为url(r'^messages/(?P<pk>[-w]+)/$', message_views.message_thread)，请求中有pk，现在它工作得很好。