CASL-Django

CASL Django is an app that converts the usual Django permissions to CASL-Style rules.

CASL is an isomorphic authorization JavaScript library: https://github.com/stalniy/casl/

Example

Having a rule called my_app.change_item, will generate a CASL rule:

{
    subject: 'my_app/item',
    action: 'change'
}

If you have more than one rule for the same subject, for example:

my_app.change_item
my_app.add_item
my_app.remove_item

This will generate:

{
    subject: 'my_app/item',
    actions: ['add', 'change', 'remove']
}

Configuration

By default, the length for subject and action fields is 128 characters, you can increase the length of them by adding to your settings file:

CASL_DJANGO = {
    'subject-length': 256,
    'action-length': 256
}

Custom Permissions

Sometimes you'd like to have custom permissions for your users, given this, you can add to your user using the Permission's add_permission class method:

from casl_django.casl.permissions import Permissions

...

my_custom_permission = Permissions.create(subject="navigation", action="index")

...

Permissions.set_user_permission(user=user, permission=my_custom_permission)

Or you can import casl_django.models.UserPermission and create objects as desired.

Quick start

1. Add "casl_django" to your INSTALLED_APPS setting like this:

   INSTALLED_APPS = [
       ...
       'casl_django',
   ]

2. Run python manage.py migrate to create the models.

API

By default, your user object should contain a related relationship called casl_permissions. You can filter by permission__subject and permission__action and finally get the rules with the queryset method bundle().

bundle()

This method it's included in the QuerySet's for UserPermissions (user.casl_permissions) and for CASLPermission (CASLPermission.objects).

This method returns a list like the following:

[
    // These are regular django permissions transformed to CASL-Style rules
    {'subject': 'products/item', actions: ['add', 'change']},
    // These are CASLPermissions objects
    {'subject': 'navigation', actions: ['index', 'products']}
]

The bundle consists in grouping same-subject rules and the actions, having less data to send over the wire.