Populating a tastypie resource for a multi-table inheritance Django model
django, django-models, tastypie
Solution
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
Problem
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() ```