Argument store added to updateEntityProperties.
This argument determines if an entity should be stored in the data model after its properties are updated.
It may be useful, for example, along with tasks (Task Queue API). One may want to make some modifications to an entity during execution of a task, but the developer is sure that at least one new task, which also wants to modify the entity, will be queued, so he or she can just update the entity without saving the changes to the data model, set the entity in memcache and the following task (which is to be executed very shortly) is to retrive the current entity from the memcache (without any expensive calls to the actual data model).
"""
30. Object pagination
Django provides a framework for paginating a list of objects in a few lines
of code. This is often useful for dividing search results or long lists of
objects into easily readable pages.
"""
from django.db import models
class Article(models.Model):
headline = models.CharField(maxlength=100, default='Default headline')
pub_date = models.DateTimeField()
def __str__(self):
return self.headline
__test__ = {'API_TESTS':"""
# prepare a list of objects for pagination
>>> from datetime import datetime
>>> for x in range(1, 10):
... a = Article(headline='Article %s' % x, pub_date=datetime(2005, 7, 29))
... a.save()
# create a basic paginator, 5 articles per page
>>> from django.core.paginator import ObjectPaginator, InvalidPage
>>> paginator = ObjectPaginator(Article.objects.all(), 5)
# the paginator knows how many hits and pages it contains
>>> paginator.hits
9
>>> paginator.pages
2
# get the first page (zero-based)
>>> paginator.get_page(0)
[<Article: Article 1>, <Article: Article 2>, <Article: Article 3>, <Article: Article 4>, <Article: Article 5>]
# get the second page
>>> paginator.get_page(1)
[<Article: Article 6>, <Article: Article 7>, <Article: Article 8>, <Article: Article 9>]
# does the first page have a next or previous page?
>>> paginator.has_next_page(0)
True
>>> paginator.has_previous_page(0)
False
# check the second page
>>> paginator.has_next_page(1)
False
>>> paginator.has_previous_page(1)
True
>>> paginator.first_on_page(0)
1
>>> paginator.first_on_page(1)
6
>>> paginator.last_on_page(0)
5
>>> paginator.last_on_page(1)
9
# Add a few more records to test out the orphans feature.
>>> for x in range(10, 13):
... Article(headline="Article %s" % x, pub_date=datetime(2006, 10, 6)).save()
# With orphans set to 3 and 10 items per page, we should get all 12 items on a single page:
>>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=3)
>>> paginator.pages
1
# With orphans only set to 1, we should get two pages:
>>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=1)
>>> paginator.pages
2
"""}