类装饰及类方法装饰器

参考文章：https://blog.csdn.net/u013380694/article/details/90019571

1.可用于类方法（post，put）中的数据验证，相当于Schema

def validate_serializer(serializer):
    """
    @validate_serializer(TestSerializer)
    def post(self, request):
        return self.success(request.data)
    """
    def validate(view_method):
        @functools.wraps(view_method)
        def handle(*args, **kwargs):
            self = args[0]
            request = args[1]
            s = serializer(data=request.data)
            if s.is_valid():
                request.data = s.data
                request.serializer = s
                return view_method(*args, **kwargs)
            else:
                return self.invalid_serializer(s)

        return handle

    return validate

2.可用于类方法权限等的认证

class BasePermissionDecorator(object):
    def __init__(self, func):
        self.func = func

    def __get__(self, obj, obj_type):
　　     #给call方法动态添加被装饰类对象作为参数
        return functools.partial(self.__call__, obj)

    def error(self, data):
        return JSONResponse.response({"error": "permission-denied", "data": data})

    def __call__(self, *args, **kwargs):
        self.request = args[1]

        if self.check_permission():
            if self.request.user.is_disabled:
                return self.error("Your account is disabled")
            return self.func(*args, **kwargs)
        else:
            return self.error("Please login first")

    def check_permission(self):
        raise NotImplementedError()


class login_required(BasePermissionDecorator):
    def check_permission(self):
        return self.request.user.is_authenticated()


class super_admin_required(BasePermissionDecorator):
    def check_permission(self):
        user = self.request.user
        return user.is_authenticated() and user.is_super_admin()


class admin_role_required(BasePermissionDecorator):
    def check_permission(self):
        user = self.request.user
        return user.is_authenticated() and user.is_admin_role()


class problem_permission_required(admin_role_required):
    def check_permission(self):
        if not super(problem_permission_required, self).check_permission():
            return False
        if self.request.user.problem_permission == ProblemPermission.NONE:
            return False
        return True

使用：

class ContestPasswordVerifyAPI(APIView):
    @validate_serializer(ContestPasswordVerifySerializer)
    @login_required
    def post(self, request):
        pass