django-treenode

Probably the best abstract model / admin for your tree based stuff.

Features

• Fast - get ancestors, children, descendants, parent, root, siblings, tree with no queries
• Synced - in-memory model instances are automatically updated
• Compatibility - you can easily add treenode to existing projects
• No dependencies
• Easy configuration - just extend the abstract model / model-admin
• Admin integration - great tree visualization: accordion, breadcrumbs or indentation

indentation (default)	breadcrumbs	accordion

Installation

• Run pip install django-treenode
• Add treenode to settings.INSTALLED_APPS
• Make your model inherit from treenode.models.TreeNodeModel (described below)
• Make your model-admin inherit from treenode.admin.TreeNodeModelAdmin (described below)
• Run python manage.py makemigrations and python manage.py migrate

Configuration

models.py

Make your model class inherit from treenode.models.TreeNodeModel:

from django.db import models

from treenode.models import TreeNodeModel


class Category(TreeNodeModel):

    # the field used to display the model instance
    # default value 'pk'
    treenode_display_field = 'name'

    name = models.CharField(max_length=50)

    class Meta(TreeNodeModel.Meta):
        verbose_name = 'Category'
        verbose_name_plural = 'Categories'

The TreeNodeModel abstract class adds many fields (prefixed with tn_ to prevent direct access) and public methods to your models.

admin.py

Make your model-admin class inherit from treenode.admin.TreeNodeModelAdmin.

from django.contrib import admin

from treenode.admin import TreeNodeModelAdmin
from treenode.forms import TreeNodeForm

from .models import Category


class CategoryAdmin(TreeNodeModelAdmin):

    # set the changelist display mode: 'accordion', 'breadcrumbs' or 'indentation' (default)
    # when changelist results are filtered by a querystring,
    # 'breadcrumbs' mode will be used (to preserve data display integrity)
    treenode_display_mode = TreeNodeModelAdmin.TREENODE_DISPLAY_MODE_ACCORDION
    # treenode_display_mode = TreeNodeModelAdmin.TREENODE_DISPLAY_MODE_BREADCRUMBS
    # treenode_display_mode = TreeNodeModelAdmin.TREENODE_DISPLAY_MODE_INDENTATION

    # use TreeNodeForm to automatically exclude invalid parent choices
    form = TreeNodeForm

admin.site.register(Category, CategoryAdmin)

settings.py

You can use a custom cache backend by adding a treenode entry to settings.CACHES, otherwise the default cache backend will be used.

CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.filebased.FileBasedCache',
        'LOCATION': '...',
    },
    'treenode': {
        'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
    },
}

Usage

Methods/Properties

Delete a node and all its descendants:

obj.delete()

Delete the whole tree for the current node class:

cls.delete_tree()

Get a list with all ancestors (ordered from root to parent):

obj.get_ancestors()
# or
obj.ancestors

Get the ancestors count:

obj.get_ancestors_count()
# or
obj.ancestors_count

Get the ancestors queryset:

obj.get_ancestors_queryset()

Get the breadcrumbs to current node (included):

obj.get_breadcrumbs(attr=None)
# or
obj.breadcrumbs

Get a list containing all children:

obj.get_children()
# or
obj.children

Get the children count:

obj.get_children_count()
# or
obj.children_count

Get the children queryset:

obj.get_children_queryset()

Get the node depth (how many levels of descendants):

obj.get_depth()
# or
obj.depth

Get a list containing all descendants:

obj.get_descendants()
# or
obj.descendants

Get the descendants count:

obj.get_descendants_count()
# or
obj.descendants_count

Get the descendants queryset:

obj.get_descendants_queryset()

Get a n-dimensional dict representing the model tree:

obj.get_descendants_tree()
# or
obj.descendants_tree

Get a multiline string representing the model tree:

obj.get_descendants_tree_display()
# or
obj.descendants_tree_display

Get the first child node:

obj.get_first_child()
# or
obj.first_child

Get the node index (index in node.parent.children list):

obj.get_index()
# or
obj.index

Get the last child node:

obj.get_last_child()
# or
obj.last_child

Get the node level (starting from 1):

obj.get_level()
# or
obj.level

Get the order value used for ordering:

obj.get_order()
# or
obj.order

Get the parent node:

obj.get_parent()
# or
obj.parent

Set the parent node:

obj.set_parent(parent_obj)

Get the node priority:

obj.get_priority()
# or
obj.priority

Set the node priority:

obj.set_priority(100)

Get the root node for the current node:

obj.get_root()
# or
obj.root

Get a list with all root nodes:

cls.get_roots()
# or
cls.roots

Get root nodes queryset:

cls.get_roots_queryset()

Get a list with all the siblings:

obj.get_siblings()
# or
obj.siblings

Get the siblings count:

obj.get_siblings_count()
# or
obj.siblings_count

Get the siblings queryset:

obj.get_siblings_queryset()

Get a n-dimensional dict representing the model tree:

cls.get_tree()
# or
cls.tree

Get a multiline string representing the model tree:

cls.get_tree_display()
# or
cls.tree_display

Return True if the current node is ancestor of target_obj:

obj.is_ancestor_of(target_obj)

Return True if the current node is child of target_obj:

obj.is_child_of(target_obj)

Return True if the current node is descendant of target_obj:

obj.is_descendant_of(target_obj)

Return True if the current node is the first child:

obj.is_first_child()

Return True if the current node is the last child:

obj.is_last_child()

Return True if the current node is leaf (it has not children):

obj.is_leaf()

Return True if the current node is parent of target_obj:

obj.is_parent_of(target_obj)

Return True if the current node is root:

obj.is_root()

Return True if the current node is root of target_obj:

obj.is_root_of(target_obj)

Return True if the current node is sibling of target_obj:

obj.is_sibling_of(target_obj)

Update tree manually, useful after bulk updates:

cls.update_tree()

Testing

# create python virtual environment
virtualenv testing_django_treenode

# activate virtualenv
cd testing_django_treenode && . bin/activate

# clone repo
git clone https://github.com/fabiocaccamo/django-treenode.git src && cd src

# install dependencies
pip install -r requirements.txt

# run tests
tox
# or
python setup.py test
# or
python -m django test --settings "tests.settings"

License

Released under MIT License.

See also

• django-admin-interface - the default admin interface made customizable by the admin itself. popup windows replaced by modals. 🧙 ⚡

• django-colorfield - simple color field for models with a nice color-picker in the admin. 🎨

• django-extra-settings - config and manage typed extra settings using just the django admin. ⚙️

• django-maintenance-mode - shows a 503 error page when maintenance-mode is on. 🚧 🛠️

• django-redirects - redirects with full control. ↪️

• python-benedict - dict subclass with keylist/keypath support, I/O shortcuts (base64, csv, json, pickle, plist, query-string, toml, xml, yaml) and many utilities. 📘

• python-codicefiscale - encode/decode Italian fiscal codes - codifica/decodifica del Codice Fiscale. 🇮🇹 💳

• python-fsutil - file-system utilities for lazy devs. 🧟‍♂️