text: Deferred foreign keys for Django
  Project description
  django-dfk
  django-dfk implements deferred foreign keys for Django. Deferred foreign keys are conceptually similar to generic foreign keys, except that they are resolved to a real foreign key at runtime, and cause proper foreign keys to be created in the database.
  This package allows you to do two things:
  * Declare that a model's foreign key field is 'deferrable', and should be repointed later * Repoint an existing model's foreign key fields, even if that model is not django-dfk aware.
  You should perform the latter with caution - consider it a similar process to monkey-patching!
  This package is alpha software, and is not feature-complete. See the TODO section for what’s on the list.
  Installation
  Install django-dfk using your preferred Python package manager. Use of virtualenv is also recommended:
  pip install django-dfk
  Usage
  Pointing a single foreign key
  Let’s say you want to reinvent the wheel, and develop a commenting app. Your comment model might look like this, in mycomments.models:
  from dfk import DeferredForeignKey class Comment(models.Model): commenter = models.ForeignKey('auth.User') content = DeferredForeignKey() body = models.TextField()
  Now, you come to integrate this application with your blog system (which, as you’re keen on wheel reinvention, you have also written yourself). Here’s blog/models.py:
  from dfk import point from mycomments.models import Comment class BlogPost(models.Model): title = models.CharField(max_length=100) slug = models.SlugField() body = models.TextField() point(Comment, 'content', BlogPost)
  The call to point will replace the DeferredForeignKey on Comment with a foreign key to BlogPost.
  Pointing may foreign keys at once
  When writing models that use deferred foreign keys, you may need to declare that a number should point to the same ‘kind’ of object. Let’s say you had wild scope creep, and your commenting app needed the ability to associate images with a blog post. So you edit your comment app’s models.py so it looks like this:
  from dfk import DeferredForeignKey class Comment(models.Model): commenter = models.ForeignKey('auth.User') content = DeferredForeignKey(name='Content') body = models.TextField() class Image(models.Model): image = models.ImageField() content = DeferredForeignKey(name='Content')
  This expresses that both comments and images need to point to the same kind of model. This is accomplished with the point_named function:
  from dfk import point_named point_named('blog', 'Content', BlogPost)
  Now, all DeferredForeignKey instances in the blog app which are called Content will be replaced by real foreign keys to BlogPost.
  Arguments to the generated foreign keys
  When declaring a deferred foreign key, you may specify additional keyword arguments. Aside from name, this will be passed on verbatim to the final foreign key.
  It is also possible to pass arbitrary keyword arguments in calls to point or point_named. These will also be passed to the final foreign key. Where arguments are present in both the DFK definition and in the point/point_named call, arguments from the latter will take precedence.
  Acknowledgements
  Thanks to ISM Fantasy Games Ltd. for sponsoring this package.
  0.0.3
  - Fix packaging error
  0.0.2
  - Fix an issue when repointing foreign keys on model classes with custom fields which use the django.db.models.SubfieldBase metaclass
  - Fix an issue migrating from Django 1.2 to 1.3.
  0.0.1
  - Initial version
  Project details
  Release history Release notifications | RSS feed
  Download files
  Download the file for your platform. If you're not sure which to choose, learn more about installing packages.