How to use a nested serializer dynamically for two serializers? - django

Question

I am working on an API, with Django, Django Rest Framework, and trying to achieve these(ad described)
First Serializer
class DeviceConfigSerializer(serializers.ModelSerializer):
config = serializers.JSONField(initial={})
context = serializers.JSONField(initial={})
templates = FilterTemplatesByOrganization(many=True)
class Meta:
model = Config
fields = ['backend', 'status', 'templates', 'context', 'config']
extra_kwargs = {'status': {'read_only': True}}
Now I have two nested serializer containing the above serializer for the LIST and DETAIL endpoints:-
Second Serializer
class DeviceListSerializer(FilterSerializerByOrgManaged, serializers.ModelSerializer):
config = DeviceConfigSerializer(write_only=True, required=False)
class Meta(BaseMeta):
model = Device
fields = ['id','name','organization','mac_address','key','last_ip','management_ip',
'model', 'os', 'system', 'notes', 'config', 'created', 'modified',]
Third Serializer
class DeviceDetailSerializer(BaseSerializer):
config = DeviceConfigSerializer(allow_null=True)
class Meta(BaseMeta):
model = Device
fields = ['id','name','organization','mac_address','key','last_ip','management_ip',
'model','os','system','notes','config','created','modified',]
Now, I am using the same DeviceConfigSerializer serializer for List, and Detail endpoint, but for the list endpoint I have set the nested serializer as write_only=True, But What I am trying to do with the list endpoint that is DeviceListSerializer serilaizer is that out of all the fields from the DeviceConfigSerializer, I want the status, and backend fields to be both read & write and others fields as write_only.
Presently with this configuration I am getting the response from the DeviceListSerializer as this:-
{
"id": "12",
"name": "tests",
"organization": "-------",
"mac_address": "-------",
"key": "------",
"last_ip": null,
"management_ip": null,
"model": "",
"os": "",
"system": "",
"notes": "",
"created": "2021-04-26T10:41:25.399160+02:00",
"modified": "2021-04-26T10:41:25.399160+02:00"
}
What I am trying to achieve is:-
{
"id": "12",
"name": "tests",
"organization": "----",
"mac_address": "-----",
"key": "----",
"last_ip": null,
"management_ip": null,
"model": "",
"os": "",
"system": "",
"notes": "",
"config": {
"status": "...",
"backend": "...",
,}
"created": "2021-04-26T10:41:25.399160+02:00",
"modified": "2021-04-26T10:41:25.399160+02:00"
}
PS: I tried by introducing an extra serializer for this two fields and nest it to the DeviceListSerializer, but I don't want to introduce an extra serializer for this two fields, and looking forward if this could be achieved with the same nested serializer.
Every Device instance contains config.
In short:-
I am trying to use the same DeviceConfigSerializer, for both DeviceListSerilaizer, and DeviceDetailSerializer. But for the DeviceListSerializer I want the status, & backend field from the DeviceConfigSerializerto be both read & write, which is presenty set to write only for the DeviceListSerializer.

Answer 1

This is not possible, so I had to introduce two new serializers for my need.

Answer 2

PrimaryKeyRelatedField may be used to represent the target of the relationship using its primary key
For example, the following serializer:
class AlbumSerializer(serializers.ModelSerializer):
tracks = serializers.PrimaryKeyRelatedField(many=True, read_only=True)
class Meta:
model = Album
fields = ['album_name', 'artist', 'tracks']
Would serialize to a representation like this:
{
'album_name': 'Undun',
'artist': 'The Roots',
'tracks': [
89,
90,
91,
...
]
}
You can use this type of approach in your serializes. Reference https://www.django-rest-framework.org/api-guide/relations/#primarykeyrelatedfield