Django Treebeard

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1. Nested Hierarchies

class Category(models.Model):
    parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
    name = models.CharField(max_length=255)

2. Ancestor Queries

categories = Category.objects.get_descendants(root_category)
ancestors = Category.objects.get_ancestors(leaf_category)

3. Level Ordering

categories = Category.objects.order_by('mptt_level')

4. Tree Depth

max_depth = Category.objects.aggregate(Max('mptt_level'))['mptt_level__max']

5. Tree Walk

for node in Category.objects.walk():
    print(node.name)

6. Siblings

siblings = Category.objects.get_siblings(category)

7. Cousins

cousins = Category.objects.get_cousins(category)

8. Deleting Nodes

category.delete_with_descendants()

9. Moving Nodes

new_parent = Category.objects.get(pk=1)
category.move_to(new_parent, 'right')

10. Custom Tree Models

class CustomTree(models.Model):
    parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
    name = models.CharField(max_length=255)

    treebeard.register(CustomTree, parent_attr='parent')

11. Ancestor Query with Custom Tree

custom_tree_nodes = CustomTree.objects.get_descendants(root_node)

12. In-Memory Tree

tree = Tree(Category.objects.all())

13. Tree Distances

distance = Category.objects.get_distance_to_root_node(leaf_node)

14. Tree Paths

path = Category.objects.get_path_to_root_node(leaf_node)

15. Node Annotations

categories = Category.objects.annotate(num_posts=F('post_set__count'))

16. Tree Selection

categories = Category.objects.get_children(parent).filter(name__startswith='A')

17. Tree Serialization

serialized_tree = treebeard.serialize(Category.objects.all())

18. Tree Deserialization

deserialized_tree = treebeard.deserialize(serialized_tree)

19. Lazy Tree

tree = treebeard.LazyTree(Category.objects.all())

20. Custom Tree Attributes

class CustomTree(models.Model):
    parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
    name = models.CharField(max_length=255)
    custom_attr = models.IntegerField()

    treebeard.register(CustomTree, parent_attr='parent')

21. Parentless Nodes

parentless_nodes = Category.objects.filter(parent__isnull=True)

22. Tree Management

tree = treebeard.register(Category)
tree.invert()
tree.fix_foreign_keys()

23. Tree Search

query = 'search term'
nodes = Category.objects.search(query)

24. Tree Hierarchy Chart

tree_chart = treebeard.render_hierarchy_chart(Category.objects.all())

25. Tree Web Interface

from treebeard.admin import TreeAdmin

class CategoryAdmin(TreeAdmin):
    pass

admin.site.register(Category, CategoryAdmin)

26. Nested Tree Structure

class NestedCategory(models.Model):
    path = models.CharField(max_length=255)
    name = models.CharField(max_length=255)

    def __str__(self):
        return self.name

27. Tree Navigation

current_node = Category.objects.get(pk=1)
siblings = current_node.get_siblings()
parent = current_node.get_parent()

28. Tree Management Signals

treebeard.register(Category)

@receiver(post_save, sender=Category)
def update_mptt_fields(sender, instance, **kwargs):
    instance.update_mptt_fields()

29. Tree RichText

from treebeard import admin as treebeard_admin

class RichTextAdmin(treebeard_admin.TreeAdmin):
    pass

admin.site.register(Category, RichTextAdmin)

30. Tree Customization

treebeard.register(Category, parent_attr='parent_id', tree_attr='parent_path')

31. Tree Permissions

from django.contrib.auth.models import Permission

permission = Permission.objects.get(codename='view_category')
category.set_permission(permission, user)

32. Tree Templates

<div data-gb-custom-block data-tag="tree_node"></div>

{{ node.name }}

<div data-gb-custom-block data-tag="tree_node_children"></div>

<div data-gb-custom-block data-tag="tree_node_end"></div>

33. Tree Serialization Using UUID

data = treebeard.serialize(Category.objects.all(), format='json', uuid_field='uuid')

34. Tree with Ordering

class OrderedCategory(models.Model):
    parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
    name = models.CharField(max_length=255)
    order = models.PositiveIntegerField(default=0)

    treebeard.register(OrderedCategory, parent_attr='parent')

35. Tree Soft Delete

from django_treebeard_softdelete import models as treebeard_softdelete

class SoftDeleteCategory(treebeard_softdelete.SoftDeleteModel, models.Model):
    parent = models.ForeignKey('self', blank=True, null=True, related_name='children')
    name = models.CharField(max_length=255)

36. Tree with Self-Referencing Foreign Key

class SelfReferencingCategory(models.Model):
    category = models.ForeignKey('self', blank=True, null=True, related_name='subcategories')
    name = models.CharField(max_length=255)

    treebeard.register(SelfReferencingCategory, parent_attr='category')