7

鉴于以下代码，我想知道如何填充RecordsResource每个真实记录数据：

models.py

class Record(models.Model):
    content_type = models.ForeignKey(ContentType, editable=False, null=True)
    user = models.ForeignKey(User, related_name='records')
    issued = models.DateTimeField(auto_now_add=True)
    date = models.DateField()

    def save(self, *args, **kwargs):
        if not self.content_type:
            self.content_type = ContentType.objects.get_for_model(self.__class__)
        super(Record, self).save(*args, **kwargs)

    def as_leaf_class(self):
        model = self.content_type.model_class()
        if model == self.__class__:
            return self
        return model.objects.get(pk=self.id)


class Record1(Record):
    # some fields

# ...

class RecordN(Record):
    # some fields

api.py

class BaseModelResource(ModelResource):
    class Meta(object):
        authentication = ApiKeyPlusWebAuthentication()
        authorization= Authorization()
        cache = SimpleCache()
        throttle = CacheDBThrottle(
            throttle_at=350,
            # 1 day
            expiration=86400
        )
        if settings.DEBUG:
            serializer = PrettyJSONSerializer()

    def obj_create(self, bundle, request=None, **kwargs):
        return super(BaseModelResource, self).obj_create(bundle, request, user=request.user)

    def apply_authorization_limits(self, request, object_list):
        return object_list.filter(user=request.user)


class BaseRecordResource(BaseModelResource):
    class Meta(BaseModelResource.Meta):
        filtering = {
            'date': ALL
        }
        excludes = ['issued']

class RecordsResource(BaseRecordResource):
    class Meta(BaseRecordResource.Meta):
        resource_name = 'records'
        queryset = Record.objects.all()

class Record1Resource(BaseRecordResource):
    class Meta(BaseRecordResource.Meta):
        resource_name = 'record1'
        queryset = Record1.objects.all()

# ...

class RecordNResource(BaseRecordResource):
    class Meta(BaseRecordResource.Meta):
        resource_name = 'recordn'
        queryset = RecordN.objects.all()
4

3 回答 3

8

好的，我刚刚解决了。我已经简化了代码。

鉴于以下代码...

models.py

from django.db import models
from model_utils.managers import InheritanceManager


class Place(models.Model):
    name = models.CharField(max_length=50)
    address = models.CharField(max_length=80)

    # https://github.com/carljm/django-model-utils#inheritancemanager
    objects = InheritanceManager()


class Restaurant(Place):
    custom_field = models.BooleanField()


class Bar(Place):
    custom_field = models.BooleanField()

api.py

from core.models import Place, Restaurant, Bar
# http://django-tastypie.readthedocs.org/en/latest/cookbook.html#pretty-printed-json-serialization
from core.utils import PrettyJSONSerializer
from tastypie.resources import ModelResource


class PlaceResource(ModelResource):
    class Meta:
        queryset = Place.objects.select_subclasses()
        resource_name = 'place'
        serializer = PrettyJSONSerializer()


class RestaurantResource(ModelResource):
    class Meta:
        queryset = Restaurant.objects.all()
        resource_name = 'restaurant'
        serializer = PrettyJSONSerializer()


class BarResource(ModelResource):
    class Meta:
        queryset = Bar.objects.all()
        resource_name = 'bar'
        serializer = PrettyJSONSerializer()

输出

http://localhost:8000/api/v1/bar/?format=json

{
  "meta": {
    "limit": 20,
    "next": null,
    "offset": 0,
    "previous": null,
    "total_count": 1
  },
  "objects": [
    {
      "address": "dawdaw",
      "custom_field": true,
      "id": "1",
      "name": "dwdwad",
      "resource_uri": "/api/v1/bar/1/"
    }
  ]
}

好的

http://localhost:8000/api/v1/restaurant/?format=json

{
  "meta": {
    "limit": 20,
    "next": null,
    "offset": 0,
    "previous": null,
    "total_count": 1
  },
  "objects": [
    {
      "address": "nhnhnh",
      "custom_field": true,
      "id": "2",
      "name": "nhnhnh",
      "resource_uri": "/api/v1/restaurant/2/"
    }
  ]
}

好的

http://localhost:8000/api/v1/place/?format=json

{
  "meta": {
    "limit": 20,
    "next": null,
    "offset": 0,
    "previous": null,
    "total_count": 2
  },
  "objects": [
    {
      "address": "dawdaw",
      "id": "1",
      "name": "dwdwad",
      "resource_uri": "/api/v1/place/1/"
    },
    {
      "address": "nhnhnh",
      "id": "2",
      "name": "nhnhnh",
      "resource_uri": "/api/v1/place/2/"
    }
  ]
}

我想要达到的目标

{
  "meta": {
    "limit": 20,
    "next": null,
    "offset": 0,
    "previous": null,
    "total_count": 2
  },
  "objects": [
    {
      "address": "dawdaw",
      "custom_field": true,
      "id": "1",
      "name": "dwdwad",
      "resource_uri": "/api/v1/bar/1/"
    },
    {
      "address": "nhnhnh",
      "custom_field": true,
      "id": "2",
      "name": "nhnhnh",
      "resource_uri": "/api/v1/restaurant/2/"
    }
  ]
}

解决方案：

from core.models import Place, Restaurant, Bar
# http://django-tastypie.readthedocs.org/en/latest/cookbook.html#pretty-printed-json-serialization
from core.utils import PrettyJSONSerializer
from tastypie.resources import ModelResource

class RestaurantResource(ModelResource):
    class Meta:
        queryset = Restaurant.objects.all()
        resource_name = 'restaurant'
        serializer = PrettyJSONSerializer()


class BarResource(ModelResource):
    class Meta:
        queryset = Bar.objects.all()
        resource_name = 'bar'
        serializer = PrettyJSONSerializer()

class PlaceResource(ModelResource):
    class Meta:
        queryset = Place.objects.select_subclasses()
        resource_name = 'place'
        serializer = PrettyJSONSerializer()

    def dehydrate(self, bundle):
        # bundle.data['custom_field'] = "Whatever you want"
        if isinstance(bundle.obj, Restaurant):
            restaurant_res = RestaurantResource()
            rr_bundle = restaurant_res.build_bundle(obj=bundle.obj, request=bundle.request)
            bundle.data = restaurant_res.full_dehydrate(rr_bundle).data
        elif isinstance(bundle.obj, Bar):
            bar_res = BarResource()
            br_bundle = bar_res.build_bundle(obj=bundle.obj, request=bundle.request)
            bundle.data = bar_res.full_dehydrate(br_bundle).data
        return bundle
于 2012-08-31T08:59:57.740 回答
3

在 RecordsResource 类中，您还需要添加模型字段（请参阅https://github.com/tomchristie/django-rest-framework/blob/master/djangorestframework/resources.py#L232-234）

class RecordsResource(BaseRecordResource):
    model = Record

    class Meta(BaseRecordResource.Meta):
        resource_name = 'records'
        queryset = Record.objects.all()
于 2012-08-19T07:47:35.413 回答
1

从头解释：

在Django 中可以使用三种继承方式。

  1. 通常，您只想使用父类来保存您不想为每个子模型输入的信息。这个类永远不会被孤立地使用，所以抽象基类是你所追求的。

  2. 如果您要对现有模型进行子类化（可能完全来自另一个应用程序）并希望每个模型都有自己的数据库表，那么多表继承就是要走的路。

  3. 最后，如果您只想修改模型的 Python 级别行为，而不以任何方式更改模型字段，则可以使用代理模型。

这里的选择是多表继承

多表继承 Django 支持的第二种模型继承类型是层次结构中的每个模型都是单独的模型。每个模型对应自己的数据库表，可以单独查询和创建。继承关系引入了子模型与其每个父模型之间的链接（通过自动创建的 OneToOneField） Ref

从你做Record的Recordx地方去，然后使用下面的东西检查它的类型1 <= x <= na_example_record = Record.objects,get(pk=3)Recordx

if hasattr(a_example_record, 'record1'):
    # ...
elif hasattr(a_example_record, 'record2'):
    # ...

因此，既然我们知道如何从父级获取子级，并且我们需要在其元数据中提供TastyPiea queryset，您需要queryset在模型上编写一个由自定义管理器支持的自定义Record，以获取您的所有记录（更多自定义查询集和管理器不破坏 DRY？），检查它是什么类型的孩子并将其附加到查询集或列表中。您可以在此处阅读如何在 Django 视图中组合 2 个或更多查询集？

于 2012-08-21T07:17:03.843 回答