1 """

     2 30. Object pagination

     3 

     4 Django provides a framework for paginating a list of objects in a few lines

     5 of code. This is often useful for dividing search results or long lists of

     6 objects into easily readable pages.

     7 """

     8 

     9 from django.db import models

    10 

    11 class Article(models.Model):

    12     headline = models.CharField(maxlength=100, default='Default headline')

    13     pub_date = models.DateTimeField()

    14 

    15     def __str__(self):

    16         return self.headline

    17 

    18 __test__ = {'API_TESTS':"""

    19 # prepare a list of objects for pagination

    20 >>> from datetime import datetime

    21 >>> for x in range(1, 10):

    22 ...     a = Article(headline='Article %s' % x, pub_date=datetime(2005, 7, 29))

    23 ...     a.save()

    24 

    25 # create a basic paginator, 5 articles per page

    26 >>> from django.core.paginator import ObjectPaginator, InvalidPage

    27 >>> paginator = ObjectPaginator(Article.objects.all(), 5)

    28 

    29 # the paginator knows how many hits and pages it contains

    30 >>> paginator.hits

    31 9

    32 

    33 >>> paginator.pages

    34 2

    35 

    36 # get the first page (zero-based)

    37 >>> paginator.get_page(0)

    38 [<Article: Article 1>, <Article: Article 2>, <Article: Article 3>, <Article: Article 4>, <Article: Article 5>]

    39 

    40 # get the second page

    41 >>> paginator.get_page(1)

    42 [<Article: Article 6>, <Article: Article 7>, <Article: Article 8>, <Article: Article 9>]

    43 

    44 # does the first page have a next or previous page?

    45 >>> paginator.has_next_page(0)

    46 True

    47 

    48 >>> paginator.has_previous_page(0)

    49 False

    50 

    51 # check the second page

    52 >>> paginator.has_next_page(1)

    53 False

    54 

    55 >>> paginator.has_previous_page(1)

    56 True

    57 

    58 >>> paginator.first_on_page(0)

    59 1

    60 >>> paginator.first_on_page(1)

    61 6

    62 >>> paginator.last_on_page(0)

    63 5

    64 >>> paginator.last_on_page(1)

    65 9

    66 

    67 # Add a few more records to test out the orphans feature.

    68 >>> for x in range(10, 13):

    69 ...     Article(headline="Article %s" % x, pub_date=datetime(2006, 10, 6)).save()

    70 

    71 # With orphans set to 3 and 10 items per page, we should get all 12 items on a single page:

    72 >>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=3)

    73 >>> paginator.pages

    74 1

    75 

    76 # With orphans only set to 1, we should get two pages:

    77 >>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=1)

    78 >>> paginator.pages

    79 2

    80 """}