This module allows you to use the neo4j graph database with Django using neomodel
- Admin functionality is very experimental. Please see todos / issues here
Live Examples (add yours 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:test@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 3.6+
- neo4j 3.5+
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 'foobar' and version 4.1.2 (current version when this was written).
Commands to run tests:
# create local venv and install dependencies.
$ python3 -m venv venv; source venv/bin/activate; python setup.py develop; export DJANGO_SETTINGS_MODULE=tests.settings;
# Go to tests
$ cd tests/
$ ./manage.py install_labels
$ ./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