May 30, 2014
Useful open-source projects start by first scratching your own itch, then scratching it again, and yet again. One of our own itches has been setting up group based user systems for applications, and the way we scratched it was by creating Django-organizations.
The concept of associating an account of some type with a person is pretty common. It makes sense where the account represents an individual identity, like a Facebook account, but less so where an account represents something like a business with multiple people who may need access. It can be pretty awful, to say nothing of a security risk, forcing multiple people to share an account. Just think of the last time you had to share a username and password with coworkers. We wrote more about this travesty a few months back in a post about designing multiple user accounts.
Django-organizations solves this by linking individual users to the account - the organization - separating individual identity and authorization from a central group account.
At the heart of the application is the organization. The base organization model is a timestamped model with an id and a name. This model then serves as the customer or group account.
To connect users, the
OrganizationUser model simply links your user
model back to the
Organization. Rather than use a plain many-to-many
relationship, the organization user model serves as a custom through
model for a many-to-many relationship on the
Organization model. This
allows for additional attributes on the through model and more
importantly a database constraint on user membership - no duplicates
The final data component is the
OrganizationOwner model. This model
allows one user to be identified as the prime owner of the account, and
is enforced by a one-to-one relationship against the
model. You can never have more then one owner of an account and an
organization user can never own more than one account.
Note that this does not prevent a user from belonging to or owning more than one account. It simply separates individual identity - name, password, email, personal profile, etc - from the business account.
Beyond the data models, Django-organizations provides some class based views for accessing and editing organizations and users. These are based on some handy mixins for restricting access to a user based on organization membership and role.
In addition there’s a pluggable backend system for handling user registration and invitations. A registration backend allows you to hook up something like email validation into your organization creation process, while an invitation backend provides a way to invite and register new users to an existing organization. The default backends will work without much work in most cases. By design they are fairly basic, allowing room for customization.
It’s getting close to two years since its first PyPI release. In that time we’ve launched it into production for several clients, and many more people have used it on their own projects, but it’s still not at the 1.0 mark. Strictly speaking it’s not even at the 0.2.0 mark, but that’s due to a shortsighted view of how it’d evolve.
When I started planning on some of the changes I wanted to make for that
release I examined how our own use cases had changed. The initial code
was based largely on immediate uses cases. We wanted auto-created
account slugs and the ability to distinguish between users with admin
rights on account and those without. Since we use django-extensions
quite a bit we required django-extensions in order to get the
AutoSlugfield, plus the
TimeStampedModel base model. These work
well, but this means we’re requiring everyone else to install
django-extensions for these two relatively minor features.
Then there’s the through model, the
OrganizationUser. When it came
down to it, we never actually made use of that
is_admin field on the
model. Aside from distinguishing between account owners and other users
users field on the
Organization model is a
ManyToMany field, a
convenience in case you want to add users via the typical M2M interface,
but is a problem for non-relational databases. django-nonrel doesn’t
support this field.
And of course there’s the organization model. In all but the simple example mentioned previously we’ve extended this model to provide things like business contact information, subscription information, college admissions data, etc. And occassionally requiring multiple types of organizations.
The downsides to the way this is handled in Django organizations now is that it requires mulit-table inheritence and prescripted use of the slug field. Mutliple organization types all build off a shared organization table with incremental IDs and slugs that must be unique across all organizations. In a scenario with only one type of organization the slug must be unique against the entire set of organizations, when in some instances it may be more useful to restrict uniqueness to a combination of other factors or simply not at all.
In 1.0 we’re going to remedy all of this.
Here’s what we’re targetting for the 1.0 release:
Organizationmodel will stil have a slug field, but it will not be required, nor will it be unique by default
The release timeframe is by end of June. As of the end of May we’ve pushed out new feature versions, including the abstract base models, Python 3.4 and Django 1.7 compatability, and documentation cookbooks.
I’d ask readers to note the support for Django 1.4 and django-nonrel. The former represents a committment to support supported versions of Django. Django 1.4 is the first long-term support release of Django and we intend to support it in this app and all others we’ve release. The latter is a good faith effort to support a user group with minimal required effort but not a committment to support. At such time as the framework supports Django without forking or we decide to ditch PostgreSQL for Mongo, we’ll reconsider.
Another fine post by Ben Lopatin.
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