Combining django-treebeard Materialized Path tree with django-model-utils InheritanceManager #django

polymorphic_tree.py

from model_utils.managers import InheritanceManagerMixin, InheritanceQuerySetMixin
from treebeard.mp_tree import MP_NodeManager, MP_NodeQuerySet, MP_Node


class PolymorphicTreeQuerySet(InheritanceQuerySetMixin, MP_NodeQuerySet):
    """QuerySet combining functionality of polymorphic up-casting with Materialized Path tree structure"""


class PolymorphicTreeManager(InheritanceManagerMixin, MP_NodeManager):
    _queryset_class = PolymorphicTreeQuerySet

    def get_queryset(self):
        return self._queryset_class(self.model).order_by('path')


class PolymorphicTreeNode(MP_Node):
    """
    Base model for tree structures using Materialized Path approach.
    """
    objects = PolymorphicTreeManager()

    class Meta:
        abstract = True