Django内置auth模块中login_required装饰器用于类视图的优雅方式

使用多继承 以及类似java中的静态代理模式

原理：OrderView.as_view()根据广度优先，调用的是LoginRequiredMixin中的as_view(cls, *args, **kwargs)

这时的cls=OrderView

接下来super(LoginRequiredMixin, cls).as_view(*args, **kwargs) 会调用到View类中的as_view()并返回一个视图函数

然后，用将这个视图函数作为参数传给Login_required(）并返回经过装饰的结果

class A(object):
 @classmethod
 def do(cls):
     print('我是你的眼')


class B(object):
 @classmethod
 def do(cls):
     print(cls)
     super(B, cls).do()
     print("--" * 12)


class C(B, A):
 pass


if __name__ == '__main__':
 C.do()
 
<class '__main__.C'>
我是你的眼
------------------------    

from django.contrib.auth.decorators import login_required


class LoginRequiredMixin(object):
    @classmethod
    def as_view(cls, *args, **kwargs):
        view = super(LoginRequiredMixin, cls).as_view(*args, **kwargs)
        return login_required(view)
        
        
        
# /user/order
class OrderView(LoginRequiredMixin, View):
    """ 用户中心 订单 """

    def get(self, request):
        context = {'page': 'order'}
        return render(request, 'user/user_center_order.html', context)        
        
        
urlpatterns = [
    url(r'^order/$', views.OrderView.as_view(), name='order'),
]