Knowledge Base: Django Generic Fields

from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType

class Message(models.Model):
  author_content_type = models.ForeignKey(
        ContentType,
        on_delete=models.CASCADE,
        related_name="messages",
    )
    author_object_id = models.UUIDField()
    author = GenericForeignKey(
        "author_content_type",
        "author_object_id"
    )
   ...

from django.db import models
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType

class Message(models.Model):
  author_content_type = models.ForeignKey(
       ContentType,
       on_delete=models.CASCADE,
       related_name="messages",
    **limit_choices_to={
           "model__in": [
               "agent",
               "customer"
           ]
       }**
   )
   author_object_id = models.UUIDField()
   author = GenericForeignKey(
       "author_content_type",
       "author_object_id"
   )

  class Meta:
        indexes = [
            models.Index(fields=["author_content_type", "author_object_id"]),
        ]

from django.contrib.contenttypes.models import ContentType
from rest_framework import viewset
from rest_framework.permissions import IsAuthenticated

from .models import Message
from .serializers import MessageSerializer

class MessageViewSet(viewsets.ModelViewSet):
    model = Message
    serializer_class = MessageSerializer
  permission_classes = [IsAuthenticated]

    def create(self, request, *args, **kwargs):
    author = request.user
        request.data['author_content_type'] = ContentType.objects.get_for_model(author).id
        request.data['author_object_id'] = request.user.id

        return super().create(request, *args, **kwargs)