This module allows you to use the neo4j graph database with Django using neomodel
- Admin functionality is very experimental. Please see todos / issues here
Install the module:
$ pip install django_neomodel
Add the following settings to your settings.py:
NEOMODEL_NEO4J_BOLT_URL = os.environ.get('NEO4J_BOLT_URL', 'bolt://neo4j:foobarbaz@localhost:7687') # Make sure django_neomodel comes before your own apps INSTALLED_APPS = ( # django.contrib.auth etc 'django_neomodel', 'yourapp' )
Write your first node definition in yourapp/models.py:
from neomodel import StructuredNode, StringProperty, DateProperty class Book(StructuredNode): title = StringProperty(unique_index=True) published = DateProperty()
Create any constraints or indexes for your labels. This needs to be done after you change your node definitions much like manage.py migrate:
$ python manage.py install_labels
Now in a view yourapp/views.py:
from .models import Book def get_books(request): return render('yourapp/books.html', request, {'books': Book.nodes.all()})
In your yourapp/admin.py:
from django_neomodel import admin as neo_admin from .models import Book class BookAdmin(dj_admin.ModelAdmin): list_display = ("title", "created") neo_admin.register(Book, BookAdmin)
And you're ready to go. Don't forget to check the neomodel documentation.
Switch the base class from StructuredNode to DjangoNode and add a 'Meta' class:
from datetime import datetime from django_neomodel import DjangoNode from neomodel import StructuredNode, StringProperty, DateTimeProperty, UniqueIdProperty class Book(DjangoNode): uid = UniqueIdProperty() title = StringProperty(unique_index=True) status = StringProperty(choices=( ('Available', 'A'), ('On loan', 'L'), ('Damaged', 'D'), ), default='Available') created = DateTimeProperty(default=datetime.utcnow) class Meta: app_label = 'library'
Create a model form class for your DjangoNode:
class BookForm(ModelForm): class Meta: model = Book fields = ['title', 'status']
This class may now be used just like any other Django form.
The following config options are available in django settings (default values shown). These are mapped to neomodel.config as django is started:
NEOMODEL_NEO4J_BOLT_URL = 'bolt://neo4j:neo4j@localhost:7687' NEOMODEL_SIGNALS = True NEOMODEL_FORCE_TIMEZONE = False NEOMODEL_MAX_CONNECTION_POOL_SIZE = 50
Signals work with DjangoNode sub-classes:
from django.db.models import signals from django_neomodel import DjangoNode from neomodel import StringProperty class Book(DjangoNode): title = StringProperty(unique_index=True) def your_signal_func(sender, instance, signal, created): pass signals.post_save.connect(your_signal_func, sender=Book)
The following are supported: pre_save, post_save, pre_delete, post_delete. On freshly created nodes created=True in the post_save signal argument.
You can create a setup method which clears the database before executing each test:
from neomodel import db, clear_neo4j_database class YourTestClass(DjangoTestCase): def setUp(self): clear_neo4j_database(db) def test_something(self): pass
The following django management commands have been included.
Setup constraints and indexes on labels for your node definitions. This should be executed after any schema changes:
$ python manage.py install_labels Setting up labels and constraints... Found tests.someapp.models.Book + Creating unique constraint for title on label Book for class tests.someapp.models.Book Finished 1 class(es).
Delete all nodes in your database, warning there is no confirmation!
- Python 3.7+
- neo4j 5.x, 4.4 (LTS)
Using Docker Compose.
Commands to setup Docker Container docker-entrypoint.sh:
# Go to tests $ cd tests/ # Docker Command (Make sure Docker is running and up to date) $ docker-compose up # login in admin with username=admin password=1234
Go to http://localhost:7474/browser/
Go to http://localhost:8000/admin/
Setup Neo4j Desktop with a local database with password 'foobarbaz' and version 5.x or 4.4.x (Neo4j LTS version).
Commands to run tests:
# create local venv and install dependencies. $ pip install -e '.[dev]'; export DJANGO_SETTINGS_MODULE=tests.settings; $ tests/manage.py install_labels $ tests/manage.py migrate $ pytest # example output: platform darwin -- Python 3.9.0, pytest-6.1.2, py-1.9.0, pluggy-0.13.1 pick 0900469 Neo4J-update-t-4.1 collected 16 items someapp/tests/test_atomicity.py . [ 6%] someapp/tests/test_commands.py .. [ 18%] someapp/tests/test_model_form.py ........... [ 87%] someapp/tests/test_sanity.py . [ 93%] someapp/tests/test_signals.py . 16 passed, 11 warnings in 1.62s