Django snippets

from django.db import models
from django.contrib.contenttypes.models import ContentType
from django.core.urlresolvers import reverse

class AutomagicModel(models.Model):
    class Meta:
        abstract=True
    def get_absolute_url(self):
        return reverse(self.get_absolute_url_alias(),kwargs={'object_id':self.id})
    def get_create_url(self):
        return reverse(self.get_create_url_alias())
    def get_index_url(self):
        return "/%s/%s/" % (self._meta.app_label,self._meta.module_name)
    def get_delete_url(self):
        return reverse(self.get_delete_url_alias(),kwargs={'object_id':self.id})
    def get_update_url(self):
        return reverse(self.get_update_url_alias(),kwargs={'object_id':self.id})

    def get_absolute_url_regexp(self):
        return "^%s/(?P<object_id>\d+)/$" % (self._meta.module_name)
    def get_create_url_regexp(self):
        return '^new/%s/$' % (self._meta.module_name)
    def get_index_url_regexp(self):
        return "^%s/page/(?P<page>[0-9|last]+)?$" % (self._meta.module_name)
    def get_delete_url_regexp(self):
        return "^%s/(?P<object_id>\d+)/delete$" % (self._meta.module_name)
    def get_update_url_regexp(self):
        return "^%s/(?P<object_id>\d+)/update$" % (self._meta.module_name)

    def get_absolute_url_alias(self):
        return "%s_%s_absolute" % (self._meta.app_label,self._meta.module_name)
    def get_create_url_alias(self):
        return '%s_%s_create' % (self._meta.app_label,self._meta.module_name)
    def get_index_url_alias(self):
        return "%s_%s_index" % (self._meta.app_label,self._meta.module_name)
    def get_delete_url_alias(self):
        return "%s_%s_delete" % (self._meta.app_label,self._meta.module_name)
    def get_update_url_alias(self):
        return "%s_%s_update" % (self._meta.app_label,self._meta.module_name)
    def build_generic_CRUD_urls(self, model_class):
        from django.conf.urls.defaults import url, patterns
        return patterns('django.views.generic',
            url(self.get_index_url_regexp(), 'list_detail.object_list', {'queryset': model_class.objects.all(),'paginate_by':2,'extra_context':{'dummy_object':self}},self.get_index_url_alias()),
            url(self.get_absolute_url_regexp(), 'list_detail.object_detail', {'queryset': model_class.objects.all()},self.get_absolute_url_alias()),
            url(self.get_create_url_regexp(), 'create_update.create_object', {'model':model_class},self.get_create_url_alias()),
            url(self.get_update_url_regexp(), 'create_update.update_object', {'model':model_class},self.get_update_url_alias()),
            url(self.get_delete_url_regexp(), 'create_update.delete_object', {'model':model_class,'post_delete_redirect':self.get_index_url()},self.get_delete_url_alias()),
        )

class Animal(AutomagicModel):
    content_type = models.ForeignKey(ContentType,editable=False,null=True)
    name = models.CharField(max_length=255)
    def __unicode__(self):
        return '('+str(self.id)+') '+self.name

class Dog(Animal):
  is_lucky = models.BooleanField()

class Cat(Animal):
  lives_left = models.IntegerField()

class Bird(Animal):
  velocity = models.IntegerField()

'''
In [1]: from animals.models import  MyModel

In [2]: m=MyModel()

In [3]: m.id=3

In [4]: m.get_create_url()
Out[4]: '/animals/new/mymodel/'

In [5]: m.get_delete_url()
Out[5]: '/animals/mymodel/3/delete'

In [6]: m.get_index_url()
Out[6]: '/animals/mymodel/'

In [7]: m.get_update_url()
Out[7]: '/animals/mymodel/3/update'

and now with a child class

In [1]: from animals.models import Dog

In [2]: d=Dog()

In [3]: d.id=4

In [4]: d.get
d.get_absolute_url  d.get_create_url    d.get_delete_url    d.get_index_url     d.get_update_url    

In [4]: d.get_update_url()
Out[4]: '/animals/dog/4/update'


Now, in your urls.py do this:

from django.conf.urls.defaults import *
from animals.models import Dog, Cat, Bird

urlpatterns = patterns('animals.views',
    url(r'^$', 'index', {},Dog._meta.app_label),
)
dog=Dog()
cat=Cat()    
bird=Bird()    
urlpatterns+=dog.build_generic_CRUD_urls(Dog)
urlpatterns+=cat.build_generic_CRUD_urls(Cat)
urlpatterns+=bird.build_generic_CRUD_urls(Bird)

this are the generated urls 

^animals/ ^dog/(page/)?(?P<page>[0-9]+)?$
^animals/ ^dog/(?P<object_id>\d+)/$
^animals/ ^new/dog/$
^animals/ ^dog/(?P<object_id>\d+)/update$
^animals/ ^dog/(?P<object_id>\d+)/delete$
^animals/ ^cat/(page/)?(?P<page>[0-9]+)?$
^animals/ ^cat/(?P<object_id>\d+)/$
^animals/ ^new/cat/$
^animals/ ^cat/(?P<object_id>\d+)/update$
^animals/ ^cat/(?P<object_id>\d+)/delete$
^animals/ ^bird/(page/)?(?P<page>[0-9]+)?$
^animals/ ^bird/(?P<object_id>\d+)/$
^animals/ ^new/bird/$
^animals/ ^bird/(?P<object_id>\d+)/update$
^animals/ ^bird/(?P<object_id>\d+)/delete$

'''