django-ordered-model

django-ordered-model allows models to be ordered and provides a simple admin interface for reordering them.

Based on http://www.djangosnippets.org/snippets/998/ and http://www.djangosnippets.org/snippets/259/

Requires:

• Django 1.4

Installation

$ python setup.py install

Usage

Add ordered_model to your SETTINGS.INSTALLED_APPS.

Inherit your model from OrderedModel to make it ordered:

from django.db import models
from ordered_model.models import OrderedModel

class Item(OrderedModel):
    name = models.CharField(max_length=100)

If you have a manytomany relationship derive the through model from OrderedModel and set group_m2m_by to the field name by which to group the entries:

class Item(models.Model):
    name = models.CharField(max_length=100)
    other_items = models.ManyToManyField(OtherItem, through='ThroughModel')

class ThroughModel(OrderedModel):
    item = models.ForeignKey(Item)
    other_item = models.ForeignKey(OtherItem)
    group_m2m_by = 'item'

Model instances now have move_up() and move_down() methods to move them relative to each other. In case of a manytomany relationship the through model instances now have the move_up and move_down methods.

To add arrows in the admin change list page to do reordering, you can use the OrderedModelAdmin and the move_up_down_links field:

from django.contrib import admin
from ordered_model.admin import OrderedModelAdmin
from models import Item

class ItemAdmin(OrderedModelAdmin):
    list_display = ('name', 'move_up_down_links')

admin.site.register(Item, ItemAdmin)

In case of the manytomany relationship add the following to the admin.py:

class ThroughModelInline(OrderedTabularInline):
    model = ThroughModel
    fields = ('item', 'other_item', 'order', 'move_up_down_links', )
    readonly_fields = ('order', 'move_up_down_links',)
    extra = 1

class ItemAdmin(admin.ModelAdmin):
    list_display = ('name', )
    filter_vertical = ('other_items', )
    inlines = (ThroughModelInline, )

    def get_urls(self):
        urls = super(ItemAdmin, self).get_urls()
        return ThroughModelInline.get_urls(self) + urls

admin.site.register(Item, ItemAdmin)

Test suite

$ ./run_tests.sh