Populating a tastypie resource for a multi-table inheritance Django model

Question

Given the following code I was wondering how to populate RecordsResource with each real record data:

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()

Answer 1

Ok, I just solved it. I've simplified the code.

Given the following code...

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()

Output

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/"
    }
  ]
}

OK

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/"
    }
  ]
}

OK

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/"
    }
  ]
}

What I want to achieve

{
  "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/"
    }
  ]
}

Solution:

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