contrib/penfield/utils.py

   1 from django.core.paginator import Paginator
   2
   3
   4 class PaginationProxy(object):
   5         def __init__(self, paginator=None, page=None, objects=None):
   6                 self.paginator = paginator
   7                 self.page = page
   8                 self.objects = objects
   9
  10         @property
  11         def page_range(self):
  12                 if not self.paginator:
  13                         return None
  14
  15                 return self.paginator.page_range
  16
  17         @property
  18         def num_pages(self):
  19                 if not self.paginator:
  20                         return None
  21
  22                 return self.paginator.num_pages
  23
  24         @property
  25         def page_number(self):
  26                 if not self.page:
  27                         return None
  28
  29                 return self.page.number
  30
  31         def __bool__(self):
  32                 return bool(self.paginator)
  33
  34
  35 def paginate(objects, per_page=None, page_number=1):
  36         """
  37         Given a list of objects, return a (page, obj_list) tuple.
  38         """
  39         try:
  40                 per_page = int(per_page)
  41         except (TypeError, ValueError):
  42                 # Then either it wasn't set or it was set to an invalid value
  43                 return PaginationProxy(objects=objects)
  44
  45         # There also shouldn't be pagination if the list is too short. Try count()
  46         # first - good chance it's a queryset, where count is more efficient.
  47         try:
  48                 if objects.count() <= per_page:
  49                         return PaginationProxy(objects=objects)
  50         except AttributeError:
  51                 if len(objects) <= per_page:
  52                         return PaginationProxy(objects=objects)
  53
  54         paginator = Paginator(objects, per_page)
  55         try:
  56                 page_number = int(page_number)
  57         except:
  58                 page_number = 1
  59
  60         try:
  61                 page = paginator.page(page_number)
  62         except EmptyPage:
  63                 page = None
  64
  65         return PaginationProxy(paginator, page, objects)