rszim/django-orderable

Add manual sort order to Django objects via an abstract base class and admin classes

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.