Django Rest Framework 自定义权限的消息未显示

Question

我正在使用 Django Rest Framework 编写应用程序。

我创建了自定义权限。我为自定义权限提供了一个 message 属性，但仍会返回默认详细信息。

让我给你我的代码。

permissions.py:

from annoying.functions import get_object_or_None
from rest_framework import permissions

from intquestions.models import IntQuestion

from ..models import Candidate, CandidatePickedIntChoice

CANDIDATE_ALREADY_ANSWERED = "This candidate already answered all questions."


class CandidateAnsweredQuestionsPermission(permissions.BasePermission):
    """
    Permission to check if the candidate has answered all questions.
    Expects candidate's email or UUID in the request's body.
    """
    message = CANDIDATE_ALREADY_ANSWERED

    def has_permission(self, request, view):
        candidate = None
        email = request.data.get("email", None)
        if email:
            candidate = get_object_or_None(Candidate, email=email)
        else:
            uuid = request.data.get("candidate", None)
            if uuid:
                candidate = get_object_or_None(Candidate, uuid=uuid)

        if candidate:
            picked_choices = CandidatePickedIntChoice.objects.filter(
                candidate=candidate
            ).count()
            total_int_questions = IntQuestion.objects.count()

            if picked_choices >= total_int_questions:
                return False

        return True

views.py:

from annoying.functions import get_object_or_None
from rest_framework import generics, status
from rest_framework.response import Response

from ..models import Candidate, CandidatePickedIntChoice
from .permissions import CandidateAnsweredQuestionsPermission
from .serializers import CandidateSerializer


class CandidateCreateAPIView(generics.CreateAPIView):
    serializer_class = CandidateSerializer
    queryset = Candidate.objects.all()
    permission_classes = (CandidateAnsweredQuestionsPermission,)

    def create(self, request, *args, **kwargs):
        candidate = get_object_or_None(Candidate, email=request.data.get("email", None))
        if not candidate:
            serializer = self.get_serializer(data=request.data)
            serializer.is_valid(raise_exception=True)
            self.perform_create(serializer)
            headers = self.get_success_headers(serializer.data)
            return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)
        else:
            serializer = self.get_serializer(candidate, data=request.data)
            serializer.is_valid(raise_exception=True)
            return Response(serializer.data, status=status.HTTP_200_OK)

注意：我正在构建的应用程序可以让候选人回答问题。我之所以这样重写create函数，是为了让还没做完所有题目的考生也能答对所有题目。

为什么权限信息是默认的"Authentication credentials were not provided."而不是我自己的？

Answer 1

消息 Authentication credentials were not provided. 说，您 未提供凭据 。它不同于 凭据错误 消息

接下来是 BasePermission class 没有属性 message，所以它不会'除非你强迫，否则不要使用你的 message 属性。 ( Source Code )

如何显示自定义 PermissionDenied 消息？
PermissionDenied 异常从 permission_denied() 方法 ove viewset 引发，( Source Code )
所以你的观点应该是这样的，

from rest_framework import exceptions


class CandidateCreateAPIView(generics.CreateAPIView):
    # your code
    def permission_denied(self, request, message=None):
        if request.authenticators and not request.successful_authenticator:
            raise exceptions.NotAuthenticated()
        raise exceptions.PermissionDenied(detail=CANDIDATE_ALREADY_ANSWERED)

Answer 2

我也遇到了同样的问题，终于找到关键点了：

不使用任何身份验证

REST_FRAMEWORK = {
    # other settings...
    'DEFAULT_AUTHENTICATION_CLASSES': [],
    'DEFAULT_PERMISSION_CLASSES': [],
}

Answer 3

我有同样的问题，我找到了解决方法，你甚至不需要AllowAny权限，只需将authentication_classes设置为一个空数组，例如：

class TestView(generics.RetrieveAPIView):
        
    renderer_classes = (JSONRenderer,)
    permission_classes = (isSomethingElse,)
    serializer_class = ProductSerializer
    authentication_classes = [] # You still need to declare it even it is empty
    
    
    def retrieve(self, request, *args, **kwargs):
        pass

希望它仍然有帮助。

Answer 4

Per Tom Christie（DRF 作者）：

I'd suggest raising a PermissionDenied explicitly if you don't want to allow the "unauthenticated vs permission denied" check to run.

他没有继续明确提到最好的地方在哪里。接受的答案似乎在视图中这样做。但是，恕我直言，我觉得最好的地方是自定义 Permission class 本身，因为一个视图可能有多个权限，其中任何一个都可能失败。

这是我的看法（为简洁起见截断了代码）：

from rest_framework import exceptions, permissions     # <-- import exceptions

CANDIDATE_ALREADY_ANSWERED = "This candidate already answered all questions."


class CandidateAnsweredQuestionsPermission(permissions.BasePermission):
    message = CANDIDATE_ALREADY_ANSWERED

    def has_permission(self, request, view):
        if picked_choices >= total_int_questions:
            raise exceptions.PermissionDenied(detail=CANDIDATE_ALREADY_ANSWERED)     # <-- raise PermissionDenied here

        return True

Django Rest Framework 自定义权限的消息未显示

Django Rest Framework Custom Permission's Message Not Shown

django

permissions

django-permissions

django-rest-framework

django-2.1