Django Nested Serializer - django

Question

I am pretty new to DRF/Django and want to create an endpoint that returns nested json from multiple models in the format:
{
"site": {
"uuid": "99cba2b8-ddb0-11eb-bd58-237a8c3c3fe6",
"domain_name": "hello.org"
},
"status": "live",
"configuration": {
"secrets": [
{
"name": "SEGMENT_KEY", # Configuration.name
"value": [...] # Configuration.value
},
{
"name": "CONFIG_KEY",
"value": [...]
},
"admin_settings": {
'tier'='trail',
'subscription_ends'='some date',
'features'=[]
}
Here are the models:
class Site(models.Model):
uuid = models.UUIDField(
default=uuid.uuid4,
editable=False,
unique=True)
domain_name = models.CharField(max_length=255, unique=True)
created = models.DateTimeField(editable=False, auto_now_add=True)
modified = models.DateTimeField(editable=False, auto_now=True)
class AdminConfiguration(models.Model):
TRIAL = 'trial'
PRO = 'pro'
TIERS = [
(TRIAL, 'Trial'),
(PRO, 'Professional'),
]
site = models.OneToOneField(
Site,
null=False,
blank=False,
on_delete=models.CASCADE)
tier = models.CharField(
max_length=255,
choices=TIERS,
default=TRIAL)
subscription_ends = models.DateTimeField(
default=set_default_expiration)
features = models.JSONField(default=list)
class Configuration(models.Model):
CSS = 'css'
SECRET = 'secret'
TYPES = [
(CSS, 'css'),
(SECRET, 'secret')
]
LIVE = 'live'
DRAFT = 'draft'
STATUSES = [
(LIVE, 'Live'),
(DRAFT, 'Draft'),
]
site = models.ForeignKey(Site, on_delete=models.CASCADE)
name = models.CharField(max_length=255, blank=False)
type = models.CharField(
max_length=255,
choices=TYPES)
value = models.JSONField(
null=True)
status = models.CharField(
max_length=20,
choices=STATUSES)
Logic behind serializer/viewset to achieve mentioned json:
retrieves lookup_field: uuid
filters query param: Configuration.status (either live or draft
filters AdminConfiguration on site id (something like AdminConfiguration.objects.get(Site.objects.get(uuid))
filters Configuration on type = secret
Here are my serializers:
class SiteSerializer(serializers.ModelSerializer):
class Meta:
model = Site
fields = [
'uuid',
'domain_name'
]
class AdminSerializer(serializers.ModelSerializer):
class Meta:
model = AdminConfiguration
fields = [
'tier',
'subscription_ends',
'features'
]
class ConfigurationSubSerializer(serializers.ModelSerializer):
class Meta:
model = Configuration
fields = [
'name',
'value',
]
class SecretsConfigSerializer(serializers.ModelSerializer):
site = SiteSerializer()
admin_settings = AdminSerializer()
status = serializers.CharField()
configuration = ConfigurationSubSerializer(many=True, source='get_secret_config')
class Meta:
model = Configuration
fields = [
'site',
'admin_settings',
'status'
'configuration'
]
def get_secret_config(self, uuid):
site = Site.objects.get(uuid=self.context['uuid'])
if self.context['status'] == 'live' or self.context['status'] == 'draft':
return Configuration.objects.filter(
site=site,
status=self.context['status'],
type='secret'
)
Viewset:
class SecretsViewSet(viewsets.ReadOnlyModelViewSet):
model = Site
lookup_field = 'uuid'
serializer_class = SecertsConfigSerializer
filter_backends = (DjangoFilterBackend,)
filterset_fields = ['status'] #query params
def get_serializer_context(self):
return {
'status': self.request.GET['status'],
'uuid': self.request.GET['uuid']
}
def get_serializer(self, *args, **kwargs):
kwargs['context'] = self.get_serializer_context()
return CombinedConfigSerializer(*args, **kwargs)
What am I missing to achieve the desired output?
output from django shell:
from site_config.models import Site, AdminConfiguration, Configuration
from site_config.serializers import SecretsConfigSerializer
site = Site.objects.get(id=2)
s = SecretsConfigSerializer(site)
s.data
### OUTPUT ###
AttributeError: Got AttributeError when attempting to get a value for field `site` on serializer `SecretsConfigSerializer`.
The serializer field might be named incorrectly and not match any attribute or key on the `Site` instance.
Original exception text was: 'Site' object has no attribute 'site'.

Answer 1

Why you don't try something more general and build your response separating the serializers like this (maybe you can use the same serializers in somewhere else):
def get(self, request, *args, **kwargs):
resp = {
'site': None,
'status': None,
'configuration': None,
'admin_settings': None,
}
sites = models.Site.objects.all()
resp['site'] = serializers.SitesSerializer(sites, many=True).data
admin_settings = models.AdminConfiguration.objects.all()
resp['admin_settings'] = serializers.AdminConfigurationSerializer(admin_settings, many=True).data
# and so
return Response(resp, status=status.HTTP_200_OK)

Answer 2

** You can try like this. This will also help to findout errors**
def get(self, request, *args, **kwargs):
resp = {
"site": None,
"status": None,
"configuration": None,
"admin_settings": None
}
sites = models.Site.objects.all()
resp['site'] = serializers.SitesSerializer(sites, many=True).data
if resp['site'].is_valid():
admin_settings = models.AdminConfiguration.objects.all()
resp['admin_settings'] = serializers.AdminConfigurationSerializer(admin_settings, many=True).data
if resp['admin_settings'].is_valid():
return Response(resp, status=status.HTTP_200_OK)
return Response(resp['admin_settings'].errors, status=status.HTTP_404_NOT_FOUND)
return Response(resp['site'].errors, status=status.HTTP_404_NOT_FOUND)