如果 Django 权限被拒绝，则返回自定义响应答案

【问题标题】：Return custom response if Django permission denied如果 Django 权限被拒绝，则返回自定义响应
【发布时间】：2020-12-18 23:41:41
【问题描述】：

我尝试通过装饰器类在 Django 中实现权限。在那里我检查用户是否已通过身份验证以及用户具有什么角色（ADMIN，HQ_ADMIN，...）

这是我的代码：

class UserPermissions(permissions.BasePermission):

    def has_permission(self, request, view):
        if not request.user and request.user.is_authenticated():
            return False

        method = request.method
        authenticator = request._authenticator

        response = self.check_permission_roles(request)

        if(response == None):
            if method == 'POST' and isinstance(authenticator, BasicAuthentication):
                return True

            if method == 'PUT' and isinstance(authenticator, BasicAuthentication):
                return True

            if method == 'DELETE' and isinstance(authenticator, BasicAuthentication):
                return True

            if method == 'GET':
                return True

        return False


    def check_permission_roles(self, request):
        """ checks the roles from the logged-in user """

        headers =  {'Access-Control-Allow-Origin':'*'}

        logged_in_user_roles = request.user.roles
        new_roles = request.DATA[models.ROLES]

        # check roles for create ADMIN
        if models.ADMIN in new_roles:
            if models.ADMIN not in logged_in_user_roles:
                return Response("no right to create role: ADMIN", status=400, headers=headers)

        # check roles for create HQ_ADMIN
        if models.HQ_ADMIN in new_roles:
            if models.ADMIN not in logged_in_user_roles:
                if models.HQ_ADMIN not in logged_in_user_roles:
                    return Response("no right to create role: HQ_ADMIN", status=400, headers=headers)

        # check roles for create HQ_USER
        if models.HQ_USER in new_roles:
            if models.ADMIN not in logged_in_user_roles:
                if models.HQ_ADMIN not in logged_in_user_roles:
                    return Response("no right to create role: HQ_USER", status=400, headers=headers)

        # check roles for create WORKSHOP_USER
        if models.WORKSHOP_USER in new_roles:
            if models.ADMIN not in logged_in_user_roles:
                if models.HQ_ADMIN not in logged_in_user_roles:
                    if models.HQ_USER not in logged_in_user_roles:
                        return Response("no right to create role: WORKSHOP_USER", status=400, headers=headers)

        # check roles for create DRIVER
        if models.DRIVER in new_roles:
            if models.ADMIN not in logged_in_user_roles:
                if models.HQ_ADMIN not in logged_in_user_roles:
                    if models.HQ_USER not in logged_in_user_roles:
                        if models.WORKSHOP_USER not in logged_in_user_roles:
                            return Response("no right to create role: DRIVER", status=400, headers=headers)

        return None

如果我现在发送一个 post 命令，并且 check_permission_roles 方法返回不是 None，我希望 Django 发送从 check_permission_roles 函数返回的响应而不是标准响应（403，您没有执行此操作的权限。） .

如何防止 Django 返回默认响应，而是返回自定义响应？

【问题讨论】：

标签： python django django-rest-framework

【解决方案1】：

回答一个老问题

您可以创建自定义异常处理程序，并在其中处理带有所需错误代码和消息的“PermissionDenied”异常

def core_exception_handler(exc, context):
    response = exception_handler(exc, context)
    handlers = {
        'PermissionDenied': _handle_error,
    }
    exception_class = exc.__class__.__name__

    if exception_class in handlers:
        return handlers[exception_class](exc, context, response)

    return response

def _handle_error(exc, context, response):
    response.status_code=401 #setting response code as 401
    response.data = {
        'errors': response.data
   }

   return response

类似的东西。

【讨论】：