Django's Generic Foreign Key Model Mixin

django_generic_fk_mixin.py

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


class GenericModelMixin(models.Model):
    model_id = models.PositiveIntegerField(blank=True, null=True, editable=False)
    model_type = models.ForeignKey(ContentType, blank=True, null=True, editable=False)
    model_object = models.GenericForeignKey('model_type', 'model_id')