Django Rest Framework自定义权限验证

Question

我有一个定制的ViewSet，它可以对数据库进行组合查询和更新。我希望建立不同级别的权限，这样我就可以授权一些用户在视图上发送GET方法，并允许其他一些用户请求POST和PUT方法。

在我找到的文件里，对于类视图，所有权限都被认为是全局的，因此我不知道如何对list方法应用一些权限，以及对ViewSet的create和update方法应用一些不同的权限。

这是ViewSet的主要代码：

class ReservationCompositionViewSet(viewsets.ViewSet):

    def list(self, request, pk):
            reservation = models.Reservation.objects.filter(booking=pk).order_by('timestamp').last()
            if reservation == None:
                raise CustomValidation(_('There is not such Reservation: {}'.format(pk)), 'booking', status.HTTP_400_BAD_REQUEST)

            result_set = serializers.ReservationSerializer(reservation).data

            result_set['pax'] = self.get_reservation_people(reservation)
            result_set['itinerary'] = self.get_reservation_composition(reservation)

            return Response(result_set)
    ...

    def create(self, request):
        reservation_data = request.data
        user = request.user

        reservation = models.Reservation()
        reservation.booking = reservation_data['booking']
        reservation.agency = models.Agency.objects.get(id=reservation_data['agency'])
        reservation.comment = reservation_data.pop('comment', None)
        reservation.status = reservation_data.pop('status', 'UNCONFIRMED')
        if reservation.status == None:
            reservation.status = 'UNCONFIRMED'
        reservation.arrival_date = reservation_data['arrival_date']
        reservation.departure_date = reservation_data['departure_date']
        reservation.confirmation = reservation_data.pop('confirmation', None)
        reservation.is_invoiced = reservation_data['is_invoiced']
        reservation.user = user

        reservation.save()

        reservation_to_return = serializers.ReservationSerializer(reservation).data
        reservation_to_return['pax'] = self.save_reservation_people(reservation, reservation_data.pop('pax'))
        reservation_to_return['itinerary'] = self.save_reservation_components(reservation, reservation_data.pop('itinerary'))

        return Response(reservation_to_return)

    def update(self, request, pk):
        reservation_data = request.data
        user = request.user

        reservation = self.save_reservation(reservation_data, user, pk)

        reservation_to_return = serializers.ReservationSerializer(reservation).data
        reservation_to_return['pax'] = self.save_reservation_people(reservation, reservation_data.pop('pax'))
        reservation_to_return['itinerary'] = self.save_reservation_components(reservation, reservation_data.pop('itinerary'))

        return Response(reservation_to_return)
        ...

我希望在调用方法can_view时验证用户具有list()权限，在调用create()或update()方法时验证can_edit权限。

Answer 1

视图集的list()、create()和update()方法是路由器对应的HTTP方法的映射。

因此，您可以创建一个自定义权限，该权限检查HTTP方法的类型，以确定正在发生的操作。

例如：

from rest_framework import permissions

class ReservationCompositionPermission(permissions.BasePermission):

    def has_permission(self, request, view):
        if request.method == 'GET':
            return request.user.has_perm('can_view')
        elif request.method in ('POST', 'PUT', 'PATCH'):
            return request.user.has_perm('can_edit')
        return False

并在视图集中指定：

class ReservationCompositionViewSet(viewsets.ViewSet):
    permission_classes = (ReservationCompositionPermission, )