django-mown (Model OWNership)
Summary
-------
This app provides a class for models to inherit from if they have the notion
of ownership (e.g. a Book belongs to a User).
The path of ownership between user and object is entirely up to you; simply
override is_owned_by() in your model to define "ownership" however you want.
Installation
------------
1) Put mown in your PYTHONPATH.
2) Subclass mown.models.HasOwner in any model that has the notion of an owner.
3) Implement is_owned_by(self, user) for all models that inherit from HasOwner.
Example, in which users own libraries and all books in those libraries:
from django.db import models
from django.contrib.auth.models import User
from mown.models import HasOwner
class Library(HasOwner, models.Model)
librarians = models.ManyToManyField(User, related_name="libraries")
name = models.CharField(max_length=80)
def is_owned_by(self, user):
if user.libraries.filter(pk=self.pk).count():
return True
return False
class Book(HasOwner, models.Model):
library = models.ForeignKey(Library, related_name="books")
title = models.CharField(max_length=200, db_index=True)
def is_owned_by(self, user):
return self.library.is_owned_by(user)
Checking Ownership
------------------
MOWN provides two facilities for checking model ownership:
Class Method:
A class method get_mine() is provided to models inheriting from HasOwner.
This method is intended to replicate the behavior of the standard model
manager get() method, with two differences:
* if the object does not exist, Http404 is raised
* if the specified user does not own the object, PermissionDenied is raised
View Decorator:
Also provided is a view decorator that has the same behavior as get_mine()
but takes a model class as a parameter. This is useful for ensuring that an
object is owned by the current user before a view is even run.
Please see the source code docstrings for details on using these facilities.