django rest框架的多个lookup_fields

Question

我有多个 API 过去使用 id 作为查找字段：

/api/organization/10

我有一个使用这些 api 的前端。

我正在构建一个新界面，出于某些原因，我想使用 slug 代替 id：

/api/organization/my-orga

API 是使用 Django Rest Framework 构建的。除了查找字段的变化外，api 的行为应该保持不变。

有没有一种解决方案可以让我的 API 同时使用 slug 和 pk ？这两条路径应该给它们相同的结果：

/api/organization/10
/api/organization/my-orga

这是我的 API 定义：

# urls.py
router = DefaultRouter()
router.register(r'organization', Organization)
urlpatterns = router.urls

#view.py
class Organization(viewsets.ModelViewSet):
    queryset = OrganisationGroup.objects.all()
    serializer_class = OrganizationSerializer

# serializer.py
class OrganizationSerializer(PermissionsSerializer):
    class Meta:
        model = Organization

Answer 1

试试这个

from django.db.models import Q
import operator
from functools import reduce
from django.shortcuts import get_object_or_404

class MultipleFieldLookupMixin(object):
    def get_object(self):
        queryset = self.get_queryset()             # Get the base queryset
        queryset = self.filter_queryset(queryset)  # Apply any filter backends
        filter = {}
        for field in self.lookup_fields:
            filter[field] = self.kwargs[field]
        q = reduce(operator.or_, (Q(x) for x in filter.items()))
        return get_object_or_404(queryset, q)

然后在视图中

class Organization(MultipleFieldLookupMixin, viewsets.ModelViewSet):
    queryset = OrganisationGroup.objects.all()
    serializer_class = OrganizationSerializer
    lookup_fields = ('pk', 'another field')

Answer 2

我通过覆盖retrieve 方法解决了类似的问题，并针对任何模式检查pk 字段的值。例如，如果它仅由数字组成。

def retrieve(self, request, *args, **kwargs):
    if kwargs['pk'].isdigit():
        return super(Organization, self).retrieve(request, *args, **kwargs)
    else:
        # get and return object however you want here.

Answer 3

我知道你很久以前问过这个问题，但这是我从所有答案中得到的完整解决方案，同时考虑了视图和网址：

把它放在你的views.py中：（通过drf稍作修改）

class MultipleFieldLookupMixin(object):

def get_object(self):
    queryset = self.get_queryset()             
    queryset = self.filter_queryset(queryset)  
    filter = {}
    for field in self.lookup_fields:
        if self.kwargs.get(field, None):  
            filter[field] = self.kwargs[field]
    obj = get_object_or_404(queryset, **filter)  # Lookup the object
    self.check_object_permissions(self.request, obj)
    return obj

然后从这个 Mixin 继承你的视图，并添加你想要的字段到 lookup_fields。像这样：

class YourDetailView(MultipleFieldLookupMixin, RetrieveUpdateAPIView):
    ...
    lookup_fields = ['pk', 'slug','code']

在 urls.py 中：

re_path(r'^organization/(?P<pk>[0-9]+)/$',
        YourDetailView),
re_path(r'^organization/(?P<slug>[-a-zA-Z0-9_]+)/$',
        YourDetailView),
re_path(r'^organization/sth_else/(?P<code>[0-9]+)/$',
        YourDetailView),

Answer 4

class MultipleFieldLookupMixin(object):
    """
    Apply this mixin to any view or viewset to get multiple field filtering
    based on a `lookup_fields` attribute, instead of the default single field filtering.
    """

    def get_object(self):
        queryset = self.get_queryset()  # Get the base queryset
        queryset = self.filter_queryset(queryset)
        filter = {}
        for field in self.lookup_fields:
            if self.kwargs[field]:  # Ignore empty fields.
                filter[field] = self.kwargs[field]
        return get_object_or_404(queryset, **filter)  # Lookup the object


class RetrieveUserView(MultipleFieldLookupMixin, generics.RetrieveAPIView):
    queryset = User.objects.all()
    serializer_class = UserSerializer
    lookup_fields = ('account', 'username')

Answer 5

我认为最好的方法是覆盖get_object(self) 方法

class Organization(generics.RetrieveAPIView):
    serializer_class = OrganizationSerializer
    queryset = Organization.objects.all()
    multiple_lookup_fields = ['pk', 'slug']

    def get_object(self):
        queryset = self.get_queryset()
        filter = {}
        for field in self.multiple_lookup_fields:
            filter[field] = self.kwargs[field]

        obj = get_object_or_404(queryset, **filter)
        self.check_object_permissions(self.request, obj)
        return obj

Answer 6

我认为根本的答案是，这不是好的 REST/API 设计，也不是 DRF 能够实现的。

Answer 7

官方文档在https://www.django-rest-framework.org/api-guide/generic-views/#creating-custom-mixins 上有一个示例

另外，您需要修改urls.py，为同一视图添加一条新路由，但使用新的字段名称。

Answer 8

这里已经有很多答案，但没有一个提供完整的描述，包括 mixin、view 和 url 配置。这个答案可以。

这是效果最好的 mixin，它从 https://www.django-rest-framework.org/api-guide/generic-views/#creating-custom-mixins 稍作修改，不会在不存在的字段上出错。

class MultipleFieldLookupMixin:
    """
    Apply this mixin to any view or viewset to get multiple field filtering
    based on a `lookup_fields` attribute, instead of the default single field filtering.

    Source: https://www.django-rest-framework.org/api-guide/generic-views/#creating-custom-mixins
    Modified to not error out for not providing all fields in the url.
    """

    def get_object(self):
        queryset = self.get_queryset()             # Get the base queryset
        queryset = self.filter_queryset(queryset)  # Apply any filter backends
        filter = {}
        for field in self.lookup_fields:
            if self.kwargs.get(field):  # Ignore empty fields.
                filter[field] = self.kwargs[field]
        obj = get_object_or_404(queryset, **filter)  # Lookup the object
        self.check_object_permissions(self.request, obj)
        return obj

现在添加视图如下，重要的是先有Mixin，否则get_object方法不会被覆盖：

class RudAPIView(MultipleFieldLookupMixin, generics.RetrieveUpdateDestroyAPIView):
    ...
    lookup_fields = ['pk', 'other_field']

现在，对于网址，我们使用默认转换器。重要的是 int 首先出现，因为它实际上会检查它是否是 int，如果不是则回退到 str。如果您有更复杂的字段，则需要使用正则表达式。

path('efficiency/<int:pk>/', views.RudAPIView.as_view(), name='something-rud'),
path('efficiency/<string:other_field>/', views.RudAPIView.as_view(), name='something-rud'),