django-hats
Role-based permissions system for Django. Everyone wears a different hat, some people wear multiple.
In a nutshell, django-hats is a reusable app, which doesn't try to re-invent the wheel by having Django Groups as its foundation. It provides a compact collection of easy to use patterns/utilities for role, and permission, based checks in CBVs and templates. They have the advantages of being: pragmatically defined, performant, clear syntax, and are well tested/documented!
Quick Start
Install with pip:
pip install django-hats
Or, getting the latest build:
pip install git+git://github.com/miketheredherring/django-hats.git@master
Add django_hats to your INSTALLED_APPS:
INSTALLED_APPS = (
...
'django_hats',
...
)Create roles.py in any registered applications in your Django project:
from django_hats.roles import Role
class Scientist(Role):
class Meta:
permissions = ('change_subject', 'change_specimen')
class GeneticCounselor(Role):
passSynchronize your database with defined roles:
python manage.py synchronize_roles
You're ready to go! Start defining permissions and securing your application!
Working with roles
Pragmatically assigning/removing/viewing Permission to role:
>>> Scientist.add_permissions(perm_1, perm_2, ...)
>>> GeneticCounselor.remove_permissions(perm_3)
>>> Scientist.get_permissions()
[<Permission 'change_subject'>, <Permission 'change_specimen'>]Assigning/removing roles for a user(works with custom user models):
>>> user = User.objects.first()
>>> Scientist.assign(user)
>>> Scientist.remove(user)Then checking if a user has a role, or multiple roles:
>>> from django_hats.utils import check_membership
>>> Scientist.check_membership(user)
True
>>> GeneticCounselor.check_membership(user)
False
>>> check_membership(user, Scientist)
True
>>> check_membership(user, [Scientist, GeneticCounselor])
False
>>> check_membership(user, [Scientist, GeneticCounselor], any=True)
TrueList users with a given role:
>>> Scientist.get_users()
[<User 'Mike Hearing'>, <User 'Scientist_1'>]Retrieving roles pragmatically:
>>> from django_hats.roles import RoleFinder
...
>>> RoleFinder.by_user(user)
[<class 'Scientist'>, ]
>>> RoleFinder.by_name('genetic_counselor')
<class 'GeneticCounselor'>
>>> RoleFinder.by_group(group)
<class 'Scientist'>Mixins
Enforcing roles on the view:
from django.views.generic import TemplateView
from django_hats.mixins import RoleRequiredMixin
from app.roles import GeneticCounselor, Scientist
class ProtectedGeneticReport(RoleRequiredMixin, TemplateView):
role_required = GeneticCounselor
template_name = 'template.html'
class ProtectedGeneticFiles(RoleRequiredMixin, TemplateView):
# Works with existing Django `PermissionRequiredMixin`
permission_required = ('change_subject', 'change_specimen')
role_required = (GeneticCounselor, Scientist)
role_required_any = True
template_name = 'template.html'Templates
Checking roles in the template like permissions:
NOTE: This is the reccomended way to check for roles in the template
settings.py
TEMPLATE_CONTEXT_PROCESSORS = (
...
'django_hats.context_processors.roles',
...
)
template.html
{% if roles.scientist %}PROTECTED CONTENT!{% endif %}
{% if roles.genetic_counselor %}NOTE: Class names are converted to snake_case if not specified in role.Meta.name{% endif %}Checking roles in the template with filter tag:
NOTE: This works without the context processor, and is not required when using the context processor, if thats your thing
{% load roles %}
{% if user|has_role:'scientist' or user|has_role:genetic_counselor_role %}PROTECTED CONTENT!{% endif %}
Signals
post_synchronize_roles
sender: django-hatsAppConfig
Management Commands
Synchronize roles/permissions from the database:
python manage.py synchronize_roles
Migrate a role which the class name/name has changed:
python manage.py migrate_role --old=OldRoleClass --new=NewRoleClass
Remove old roles/permissions from the database(only post migration if a name change occured):
python manage.py cleanup_roles