Django基于类的视图：在调度中验证对象

Question

在get/post中稍后调用self.get_object()时，是否存在已确认的方式，可以在调度中验证对象而不会进行额外的数据库调用？

这里是我迄今（略有这个问题改变）：

class CourseUpdateView(UpdateView): 
    def dispatch(self, request, *args, **kwargs): 

     self.request = request 
     self.kwargs = kwargs 
     self.object = self.get_object() 

     if self.object.is_online: 
      messages.warning(request, "Sorry this one can't be updated") 
      return redirect("course:detail", pk=self.kwargs['pk']) 

     # this is going to call self.get_object again isn't it? 
     return UpdateView.dispatch(self, request, *args, **kwargs) 

Answer 1

可以缓存的get_object()结果。

这里有一个简单的例子：

class CourseUpdateView(UpdateView): 
    # [...] your dispatch method 

    def get_object(self): 
     # it doesn't matter how many times get_object is called per request 
     # it should not do more than one request 
     if not hasattr(self, '_object'): 
      self._object = super(CourseUpdateView, self).get_object() 
     return self._object