Re: get_next_by title?

[Javier Guerra Giraldez]

On Fri, Apr 23, 2010 at 1:29 AM, ChrisR <robthech...@gmail.com> wrote:
>        def get_prev_by_title(self):
>                get_prev = Product.objects.order_by('-
> title').filter(title__lt=self.title)
>                try:
>                        return get_prev[0]
>                except IndexError:
>                        return None
>
>
>        def get_next_by_title(self):
>                get_next =
> Product.objects.order_by('title').filter(title__gt=self.title)
>                try:
>                        return get_next[0]
>                except IndexError:
>                        return None

just a little DRYer:

====== take 1 ========
def firstornone (q):
    try:
        return q[0]
    except IndexError:
        return None

.............

       def get_prev_by_title(self):
               return
firstornone(Product.objects.order_by('-title').filter(title__lt=self.title))

       def get_next_by_title(self):
               return
firstornone(Product.objects.order_by('title').filter(title__gt=self.title))

====================
or even:
======== take 2 =======
def next_by (queryset, field, value):
    return firstornone
(queryset.order_by(field).filter(**{'%s__gt'%field:value}))
def prev_by (queryset, field, value):
    return firstornone
(queryset.order_by('-'+field).filter(**{'%s__lt'%field:value}))

.....
       def get_prev_by_title(self):
               return prev_by(Product.objects.all(), 'title', self.title)

       def get_next_by_title(self):
               return next_by(Product.objects.all(), 'title', self.title)

=================

(a slow morning, i felt the itch to code a little....)

-- 
Javier

-- 
You received this message because you are subscribed to the Google Groups 
"Django users" group.
To post to this group, send email to django-us...@googlegroups.com.
To unsubscribe from this group, send email to 
django-users+unsubscr...@googlegroups.com.
For more options, visit this group at 
http://groups.google.com/group/django-users?hl=en.