Django Orderable

Add manual sort order to Django objects via an abstract base class and admin classes. Project includes:

• Abstract base Model
• Admin class
• Inline admin class
• Admin templates

Demo

Installation

Grab from the PyPI:

pip install django-orderable

Add to your INSTALLED_APPS:

...
'orderable',
...

Subclass the Orderable class:

from orderable.models import Orderable


class Book(Orderable):
    ...

Subclass the appropriate Orderable admin classes:

from orderable.admin import OrderableAdmin, OrderableTabularInline


class SomeInlineClass(OrderableTabularInline):
    ...

class SomeAdminClass(OrderableAdmin):
    list_display = ('__unicode__', 'sort_order_display')
    ...

jQuery and jQuery UI are used in the Admin for the draggable UI. You may override the versions with your own (rather than using Google's CDN):

class SomeAdminClass(OrderableAdmin):
    class Media:
        extend = False
        js = (
            'path/to/jquery.js',
            'path/to/jquery.ui.js',
        )

Notes

class Meta

If your subclass of Orderable defines class Meta then make sure it subclasses Orderable.Meta one so the model is sorted by sort_order. ie:

class MyOrderable(Orderable):
    class Meta(Orderable.Meta):
        ...

Custom Managers

Similarly, if your model has a custom manager, subclass orderable.managers.OrderableManager instead of django.db.models.Manager.

Transactions

Saving orderable models invokes a fair number of database queries, and in order to avoid race conditions should be run in a transaction.

Adding Orderable to Existing Models

You will need to populate the required sort_order field. Typically this is done by adding the field in one migration with a default of 0, then creating a data migration to set the value to that of its primary key:

for obj in orm['appname.Model'].objects.all():
    obj.sort_order = obj.pk
    obj.save()

Multiple Models using Orderable

When multiple models inherit from Orderable the next() and previous() methods will look for the next/previous model with a sort order. However you'll likely want to have the various sort orders determined by a foreign key or some other predicate. The easiest way (currently) is to override the method in question.