Usage

Lets assume that our model looks like this.

models.py

from django import models
from django_ltree import TreeModel

class CustomTree(TreeModel):
    text = models.TextField()

Create a child without parent

views.py

from .models import CustomTree

CustomTree.objects.create_child(text='Hello world')

The following code with create a child with no parent (ie:roots of a tree)

Create a child with parent

Let’s assume we want to add a child to the CustomTree object of pk=1

views.py

from .models import CustomTree

# This must return a single object
parent: CustomTree = CustomTree.objects.get(pk=1)
CustomTree.objects.create_child(text='Hello world', parent=parent)

Get all the roots of the model

A root means the the object that childrens anchor to.

views.py

from .models import CustomTree

roots: list[CustomTree] = CustomTree.objects.roots()

Get all the childrens of a object

To get the childrens of a object, we can first get the object then call the QuerySet specific children function.

views.py

from .models import CustomTree

instance = CustomTree.objects.get(pk=1)

childrens: list[CustomTree] = instance.children()

Get the length of childrens of a object

django specific database functions still work when we call the filter method.

Lets assume we want to get the childrens of CustomTree object whose pk is 1.

views.py

from .models import CustomTree

instance = CustomTree.objects.get(pk=1)

childrens: int = instance.children().count()