获取最近创建的对象的 id Django Rest Framework

Question

我正在使用 Django REST Framework 为我的移动应用程序提供 API。我需要在创建新设备时将其所有者的电子邮件作为额外参数发送。

实际上我发送了一个类似这样的json：

{"os_type": "AND",
 "token": "dfsdfdfsd",
 "email": "sdfdfd@sdfs.com"
}

我需要将一些数据传递给标准 ModelViewSet 并覆盖一小部分（提取所有者的电子邮件并将其与最近创建的设备相关联。问题是我不知道如何获取 id这个新对象。

我的设备型号有这个 ModelViewSet：

class DeviceViewSet(viewsets.ModelViewSet):

    queryset = Device.objects.all()
    serializer_class = DeviceSerializer

    def create(self, request):
        """
            Overrides the create method in order to get
            extra params: the email of the device's owner.
            When this is done, we pass the method to his parent.
        """
        print "creating..."

        created = super(DeviceViewSet, self).create(request)
        print type(created).__name__
        #[method for method in dir(created) if callable(getattr(created, method))]
        return created

"created" 对象是 Response 类型，它将使用所有 de 信息呈现，但我想以更优雅或正确的方式获取 ID。

这是我的设备型号：

class Device(models.Model):
    """
    iOS or Android device, where is installed the app
    """

    ANDROID = 'AND'
    IOS = 'IOS'

    OS_DEVICES_CHOICES = (
        (ANDROID, 'Android'),
        (IOS, 'iOS'),
    )

    os_type = models.CharField(max_length=3, choices=OS_DEVICES_CHOICES)
    token = models.CharField(max_length=1000)

    active = models.BooleanField(default=True)

    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

我不想在我的设备模型中添加字段所有者，因为我已经有引用设备的所有者模型：

class Owner(models.Model):
    name = models.CharField(max_length=200, blank=True, null=True)
    biography = models.TextField(max_length=1000, blank=True, null=True)
    birthday = models.DateField(blank=True, null=True)
    country = models.CharField(max_length=50, blank=True, null=True)
    language = models.CharField(max_length=50, blank=True, null=True)

    email = models.EmailField(blank=True, null=True)

    devices = models.ManyToManyField(Device)

    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    def __str__(self):
        return u'[{0}] {1}'.format(self.id, self.name)

    def __unicode__(self):
        return u'[{0}] {1}'.format(self.id, self.name)

如何解决这个问题？

Answer 1

终于解决了我自己编写代码保存序列化器对象并直接获取ID的问题。

这是完整代码：

class DeviceViewSet(viewsets.ModelViewSet):

    queryset = Device.objects.all()
    serializer_class = DeviceSerializer

    def create(self, request):
        """
            Overrides the create method in order to get
            extra params: the email of the device's owner.
            When this is done, we pass the method to his parent.
        """
        print "creating..."
        data = request.data
        email = None
        if 'email' in data:
            email = data['email']
        else:
            return Response("No owner email provided", status=status.HTTP_400_BAD_REQUEST)

        try:
            owner = Owner.objects.get(email=email)
        except Exception as e:
            print e
            return Response('No owner with the email ({0}) found, error: {1}'.format(email, e), 
                status=status.HTTP_406_NOT_ACCEPTABLE)


        serializer = DeviceSerializer(data=request.data)
        if serializer.is_valid():
            device = serializer.save()
            print device.id
            owner.devices.add(device)
            #device.save()
            return Response(serializer.data, status=status.HTTP_201_CREATED)
        else:
            return Response(serializer.errors,
                            status=status.HTTP_400_BAD_REQUEST)

Answer 2

您可以在 Django REST Framework 中通过 overriding perform_create on your view 创建对象后执行操作。

class DeviceViewSet(viewsets.ModelViewSet):
    queryset = Device.objects.all()
    serializer_class = DeviceSerializer

    def perform_create(self, serializer):
        from rest_framework.exceptions import ValidationError

        data = self.request.data

        if "email" not in data:
            raise ValidationError({
                "email": "No owner email provided",
            })

        try:
            owner = Owner.objects.get(email=data["email"])
        except Owner.DoesNotExist:
            return Response(
                'No owner with the email ({0}) found'.format(email),
                status=status.HTTP_406_NOT_ACCEPTABLE
            )

        device = serializer.save()

        owner.devices.add(device)

通过覆盖视图上的 perform_create 而不是 create 方法，您不必担心对 create 方法所做的任何更改会丢失在升级过程中。 perform_create 方法是推荐的钩子，因此您无需担心会中断。

我还对在创建设备之前进行的检查进行了一些更改。

A ValidationError is being raised 当电子邮件未随请求一起传递时出现 400 错误。这将产生与其他字段相同样式的错误消息，应由默认异常处理程序处理。
try...except 仅限于 DoesNotExist 错误，如果用户提供的电子邮件与数据库中的所有者不匹配，则会触发该错误。这将防止您压缩未考虑的边缘情况，though the DoesNotExist and MultipleObjectsReturned exceptions 是您真正应该从 get 调用中收到的唯一情况。
未知邮件的错误不再包含异常通知，已经存在的邮件应该没问题。

此外，如果有办法将发出请求的当前用户（在 request.user 中提供）与正在创建的设备的所有者（在本例中为 owner）联系起来，您可能想跳过他们提供的电子邮件。这当然取决于 API 应该如何运作，因为您可能有兴趣允许用户将设备绑定到另一个所有者的帐户。

获取最近创建的对象的 id Django Rest Framework

Get the id of the object recently created Django Rest Framework

python

django

django-rest-framework