Development with Python

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lists/views.py (ch10l026-3).
def new_list (request):
[... ]
return redirect( 'view_list', list_.id )
That would get the unit and functional tests passing, but the redirect function can do
even better magic than that! In Django, because model objects are often associated with
a particular URL, you can define a special function called get_absolute_url which says
what page displays the item. It’s useful in this case, but it’s also useful in the Django
admin (which I don’t cover in the book, but you’ll soon discover for yourself): it will let
you jump from looking at an object in the admin view to looking at the object on the
live site. I’d always recommend defining a get_absolute_url for a model whenever
there is one that makes sense; it takes no time at all.
All it takes is a super-simple unit test in test_models.py :
lists/tests/test_models.py (ch10l026-4).
def test_get_absolute_url(self):
list_ = List .objects.create()
self. assertEqual(list_.get_absolute_url(), '/lists/%d/' % (list_. id,))
Which gives:
AttributeError: 'List' object has no attribute 'get_absolute_url'
And the implementation is to use Django’s reverse function, which essentially does the
reverse of what Django normally does with urls.py (see :
lists/models.py (ch10l026-5).
from django.core.urlresolvers import reverse
class List(models .Model):
def get_absolute_url (self):
return reverse('view_list', args= [self.id])
And now we can use it in the view—the redirect function just takes the object we want
to redirect to, and it uses get_absolute_url under the hood automagically!
lists/views.py (ch10l026-6).
def new_list (request):
[... ]
return redirect( list_)
There’s more info in the . Quick check that the unit tests still pass:
OK
Then we do the same to view_list :
Refactor: Removing Hardcoded URLs | 189