Django rest框架，在同一个ModelViewSet中使用不同的序列化器

我想提供两种不同的序列化器，并且能够从ModelViewSet的所有功能中受益:

当查看对象列表时，我希望每个对象都有一个url，该url重定向到其详细信息，并且每个其他关系都使用目标模型的__unicode __出现;

例子:

{
  "url": "http://127.0.0.1:8000/database/gruppi/2/",
  "nome": "universitari",
  "descrizione": "unitn!",
  "creatore": "emilio",
  "accesso": "CHI",
  "membri": [
    "emilio",
    "michele",
    "luisa",
    "ivan",
    "saverio"
  ]
}

在查看对象的详细信息时，我希望使用默认的HyperlinkedModelSerializer

例子:

{
  "url": "http://127.0.0.1:8000/database/gruppi/2/",
  "nome": "universitari",
  "descrizione": "unitn!",
  "creatore": "http://127.0.0.1:8000/database/utenti/3/",
  "accesso": "CHI",
  "membri": [
    "http://127.0.0.1:8000/database/utenti/3/",
    "http://127.0.0.1:8000/database/utenti/4/",
    "http://127.0.0.1:8000/database/utenti/5/",
    "http://127.0.0.1:8000/database/utenti/6/",
    "http://127.0.0.1:8000/database/utenti/7/"
  ]
}

我通过以下方法做到了这一切:

serializers.py

# serializer to use when showing a list
class ListaGruppi(serializers.HyperlinkedModelSerializer):
    membri = serializers.RelatedField(many = True)
    creatore = serializers.RelatedField(many = False)

    class Meta:
        model = models.Gruppi

# serializer to use when showing the details
class DettaglioGruppi(serializers.HyperlinkedModelSerializer):
    class Meta:
        model = models.Gruppi

views.py

class DualSerializerViewSet(viewsets.ModelViewSet):
    """
    ViewSet providing different serializers for list and detail views.

    Use list_serializer and detail_serializer to provide them
    """
    def list(self, *args, **kwargs):
        self.serializer_class = self.list_serializer
        return viewsets.ModelViewSet.list(self, *args, **kwargs)

    def retrieve(self, *args, **kwargs):
        self.serializer_class = self.detail_serializer
        return viewsets.ModelViewSet.retrieve(self, *args, **kwargs)

class GruppiViewSet(DualSerializerViewSet):
    model = models.Gruppi
    list_serializer = serializers.ListaGruppi
    detail_serializer = serializers.DettaglioGruppi

    # etc.

基本上，我检测用户何时请求列表视图或详细视图，并更改serializer_class以满足我的需要。但我对这段代码并不满意，它看起来像一个肮脏的黑客，最重要的是，如果两个用户同时请求一个列表和一个细节怎么办?

是否有更好的方法来实现这个使用ModelViewSets或我必须返回使用GenericAPIView?

编辑: 下面是如何使用一个自定义的基础ModelViewSet:

class MultiSerializerViewSet(viewsets.ModelViewSet):
    serializers = { 
        'default': None,
    }

    def get_serializer_class(self):
            return self.serializers.get(self.action,
                        self.serializers['default'])

class GruppiViewSet(MultiSerializerViewSet):
    model = models.Gruppi

    serializers = {
        'list':    serializers.ListaGruppi,
        'detail':  serializers.DettaglioGruppi,
        # etc.
    }

当前回答

您可能会发现这个mixin很有用，它覆盖了get_serializer_class方法，并允许您声明一个dict，该dict将动作和序列化器类或回滚映射到通常的行为。

class MultiSerializerViewSetMixin(object):
    def get_serializer_class(self):
        """
        Look for serializer class in self.serializer_action_classes, which
        should be a dict mapping action name (key) to serializer class (value),
        i.e.:

        class MyViewSet(MultiSerializerViewSetMixin, ViewSet):
            serializer_class = MyDefaultSerializer
            serializer_action_classes = {
               'list': MyListSerializer,
               'my_action': MyActionSerializer,
            }

            @action
            def my_action:
                ...

        If there's no entry for that action then just fallback to the regular
        get_serializer_class lookup: self.serializer_class, DefaultSerializer.

        """
        try:
            return self.serializer_action_classes[self.action]
        except (KeyError, AttributeError):
            return super(MultiSerializerViewSetMixin, self).get_serializer_class()

2014-04-07 20:14:20

其他回答

关于提供不同的序列化器，为什么没有人选择检查HTTP方法的方法?在我看来，这样更清楚，也不需要额外的检查。

def get_serializer_class(self):
    if self.request.method == 'POST':
        return NewRackItemSerializer
    return RackItemSerializer

/来源:# issuecomment-42357718 https://github.com/encode/django-rest-framework/issues/1563拨款

2017-11-16 21:36:13

基于@gonz和@user2734679 answers，我创建了这个小的python包，它以ModelViewset的子类的形式提供了这个功能。下面是它的工作原理。

from drf_custom_viewsets.viewsets.CustomSerializerViewSet
from myapp.serializers import DefaltSerializer, CustomSerializer1, CustomSerializer2

class MyViewSet(CustomSerializerViewSet):
    serializer_class = DefaultSerializer
    custom_serializer_classes = {
        'create':  CustomSerializer1,
        'update': CustomSerializer2,
    }

2016-06-24 09:06:21

您可能会发现这个mixin很有用，它覆盖了get_serializer_class方法，并允许您声明一个dict，该dict将动作和序列化器类或回滚映射到通常的行为。

class MultiSerializerViewSetMixin(object):
    def get_serializer_class(self):
        """
        Look for serializer class in self.serializer_action_classes, which
        should be a dict mapping action name (key) to serializer class (value),
        i.e.:

        class MyViewSet(MultiSerializerViewSetMixin, ViewSet):
            serializer_class = MyDefaultSerializer
            serializer_action_classes = {
               'list': MyListSerializer,
               'my_action': MyActionSerializer,
            }

            @action
            def my_action:
                ...

        If there's no entry for that action then just fallback to the regular
        get_serializer_class lookup: self.serializer_class, DefaultSerializer.

        """
        try:
            return self.serializer_action_classes[self.action]
        except (KeyError, AttributeError):
            return super(MultiSerializerViewSetMixin, self).get_serializer_class()

2014-04-07 20:14:20

这个答案和公认的答案是一样的，但我更喜欢这样做。

一般的观点

get_serializer_class(自我): 返回应该用于序列化器的类。默认返回serializer_class属性。可以重写以提供动态行为，例如为读写操作使用不同的序列化器，或者为不同类型的用户提供不同的序列化器。 serializer_class属性。

class DualSerializerViewSet(viewsets.ModelViewSet):
    # mapping serializer into the action
    serializer_classes = {
        'list': serializers.ListaGruppi,
        'retrieve': serializers.DettaglioGruppi,
        # ... other actions
    }
    default_serializer_class = DefaultSerializer # Your default serializer

    def get_serializer_class(self):
        return self.serializer_classes.get(self.action, self.default_serializer_class)

2019-09-18 09:09:56

重写get_serializer_class方法。在模型mixin中使用此方法检索适当的Serializer类。

注意，还有一个get_serializer方法，它返回正确Serializer的实例

class DualSerializerViewSet(viewsets.ModelViewSet):
    def get_serializer_class(self):
        if self.action == 'list':
            return serializers.ListaGruppi
        if self.action == 'retrieve':
            return serializers.DettaglioGruppi
        return serializers.Default # I dont' know what you want for create/destroy/update.

2014-03-31 07:18:42

Django rest框架，在同一个ModelViewSet中使用不同的序列化器

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