Metadata-Version: 1.1
Name: django-modelcluster
Version: 0.2
Summary: Django extension to allow working with 'clusters' of models as a single unit, independently of the database
Home-page: https://github.com/torchbox/django-modelcluster
Author: Matthew Westcott
Author-email: matthew.westcott@torchbox.com
License: BSD
Description: django-modelcluster
        ===================
        
        If you had a data model like this::
        
         class Band(models.Model):
             name = models.CharField(max_length=255)
        
         class BandMember(models.Model):
             band = models.ForeignKey('Band', related_name='members')
             name = models.CharField(max_length=255)
        
        
        wouldn't it be nice if you could construct bundles of objects like this, independently of the database::
        
         beatles = Band(name='The Beatles')
         beatles.members = [
             BandMember(name='John Lennon'),
             BandMember(name='Paul McCartney'),
         ]
        
        Unfortunately, you can't. Objects need to exist in the database for foreign key relations to work::
        
         IntegrityError: null value in column "band_id" violates not-null constraint
        
        But what if you could? There are all sorts of scenarios where you might want to work with a 'cluster' of related objects, without necessarily holding them in the database: maybe you want to render a preview of the data the user has just submitted, prior to saving. Maybe you need to construct a tree of things, serialize them and hand them off to some external system. Maybe you have a workflow where your models exist in an incomplete 'draft' state for an extended time, or you need to handle multiple revisions, and you don't want to redesign your database around that requirement.
        
        **django-modelcluster** extends Django's foreign key relations to make this possible. It introduces a new type of relation, *ParentalKey*, where the related models are stored locally to the 'parent' model until the parent is explicitly saved. Up to that point, the related models can still be accessed through a subset of the QuerySet API::
        
         class Band(ClusterableModel):
             name = models.CharField(max_length=255)
        
         class BandMember(models.Model):
             band = ParentalKey('Band', related_name='members')
             name = models.CharField(max_length=255)
        
        
         >>> beatles = Band(name='The Beatles')
         >>> beatles.members = [
         ...     BandMember(name='John Lennon'),
         ...     BandMember(name='Paul McCartney'),
         ... ]
         >>> [member.name for member in beatles.members.all()]
         ['John Lennon', 'Paul McCartney']
         >>> beatles.members.add(BandMember(name='George Harrison'))
         >>> beatles.members.count()
         3
         >>> beatles.save()  # only now are the records written to the database
        
        For more examples, see the unit tests.
        
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: BSD License
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.6
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.2
Classifier: Programming Language :: Python :: 3.3
Classifier: Programming Language :: Python :: 3.4
Classifier: Framework :: Django
