Added a new and improved Paginator class, which allows you to pass a Page object to the template instead of 5 or 6 separate variables. ObjectPaginator still exists for backwards compatibility but issues a DeprecationWarning
git-svn-id: http://code.djangoproject.com/svn/django/trunk@7306 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Adrian Holovaty
parent
855bc7b09d
commit
d67208f5be
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@ -1,46 +1,149 @@
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class InvalidPage(Exception):
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pass
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class ObjectPaginator(object):
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"""
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This class makes pagination easy. Feed it a QuerySet or list, plus the number
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of objects you want on each page. Then read the hits and pages properties to
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see how many pages it involves. Call get_page with a page number (starting
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at 0) to get back a list of objects for that page.
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class Paginator(object):
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def __init__(self, object_list, per_page, orphans=0, allow_empty_first_page=True):
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self.object_list = object_list
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self.per_page = per_page
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self.orphans = orphans
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self.allow_empty_first_page = allow_empty_first_page
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self._num_pages = self._count = None
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Finally, check if a page number has a next/prev page using
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has_next_page(page_number) and has_previous_page(page_number).
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Use orphans to avoid small final pages. For example:
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13 records, num_per_page=10, orphans=2 --> pages==2, len(self.get_page(0))==10
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12 records, num_per_page=10, orphans=2 --> pages==1, len(self.get_page(0))==12
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def validate_number(self, number):
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"Validates the given 1-based page number."
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try:
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number = int(number)
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except ValueError:
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raise InvalidPage('That page number is not an integer')
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if number < 1:
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raise InvalidPage('That page number is less than 1')
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if number > self.num_pages:
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if number == 1 and self.allow_empty_first_page:
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pass
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else:
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raise InvalidPage('That page contains no results')
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return number
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def page(self, number):
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"Returns a Page object for the given 1-based page number."
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number = self.validate_number(number)
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bottom = (number - 1) * self.per_page
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top = bottom + self.per_page
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if top + self.orphans >= self.count:
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top = self.count
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return Page(self.object_list[bottom:top], number, self)
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def _get_count(self):
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"Returns the total number of objects, across all pages."
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if self._count is None:
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self._count = len(self.object_list)
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return self._count
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count = property(_get_count)
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def _get_num_pages(self):
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"Returns the total number of pages."
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if self._num_pages is None:
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hits = self.count - 1 - self.orphans
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if hits < 1:
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hits = 0
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if hits == 0 and not self.allow_empty_first_page:
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self._num_pages = 0
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else:
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self._num_pages = hits // self.per_page + 1
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return self._num_pages
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num_pages = property(_get_num_pages)
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def _get_page_range(self):
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"""
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Returns a 1-based range of pages for iterating through within
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a template for loop.
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"""
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return range(1, self.num_pages + 1)
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page_range = property(_get_page_range)
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class QuerySetPaginator(Paginator):
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"""
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Like Paginator, but works on QuerySets.
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"""
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def _get_count(self):
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if self._count is None:
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self._count = self.object_list.count()
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return self._count
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count = property(_get_count)
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class Page(object):
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def __init__(self, object_list, number, paginator):
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self.object_list = object_list
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self.number = number
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self.paginator = paginator
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def __repr__(self):
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return '<Page %s of %s>' % (self.number, self.paginator.num_pages)
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def has_next(self):
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return self.number < self.paginator.num_pages
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def has_previous(self):
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return self.number > 1
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def has_other_pages(self):
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return self.has_previous() or self.has_next()
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def next_page_number(self):
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return self.number + 1
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def previous_page_number(self):
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return self.number - 1
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def start_index(self):
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"""
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Returns the 1-based index of the first object on this page,
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relative to total objects in the paginator.
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"""
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return (self.paginator.per_page * (self.number - 1)) + 1
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def end_index(self):
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"""
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Returns the 1-based index of the last object on this page,
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relative to total objects found (hits).
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"""
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if self.number == self.paginator.num_pages:
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return self.paginator.count
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return self.number * self.paginator.per_page
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class ObjectPaginator(Paginator):
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"""
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Legacy ObjectPaginator class, for backwards compatibility.
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Note that each method on this class that takes page_number expects a
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zero-based page number, whereas the new API (Paginator/Page) uses one-based
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page numbers.
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"""
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def __init__(self, query_set, num_per_page, orphans=0):
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Paginator.__init__(self, query_set, num_per_page, orphans)
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import warnings
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warnings.warn("The ObjectPaginator is deprecated. Use django.core.paginator.Paginator instead.", DeprecationWarning)
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# Keep these attributes around for backwards compatibility.
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self.query_set = query_set
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self.num_per_page = num_per_page
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self.orphans = orphans
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self._hits = self._pages = None
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self._page_range = None
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def validate_page_number(self, page_number):
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try:
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page_number = int(page_number)
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page_number = int(page_number) + 1
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except ValueError:
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raise InvalidPage
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if page_number < 0 or page_number > self.pages - 1:
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raise InvalidPage
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return page_number
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return self.validate_number(page_number)
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def get_page(self, page_number):
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page_number = self.validate_page_number(page_number)
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bottom = page_number * self.num_per_page
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top = bottom + self.num_per_page
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if top + self.orphans >= self.hits:
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top = self.hits
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return self.query_set[bottom:top]
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try:
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page_number = int(page_number) + 1
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except ValueError:
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raise InvalidPage
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return self.page(page_number).object_list
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def has_next_page(self, page_number):
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"Does page $page_number have a 'next' page?"
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return page_number < self.pages - 1
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def has_previous_page(self, page_number):
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@ -52,7 +155,7 @@ class ObjectPaginator(object):
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relative to total objects found (hits).
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"""
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page_number = self.validate_page_number(page_number)
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return (self.num_per_page * page_number) + 1
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return (self.num_per_page * (page_number - 1)) + 1
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def last_on_page(self, page_number):
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"""
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@ -60,40 +163,23 @@ class ObjectPaginator(object):
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relative to total objects found (hits).
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"""
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page_number = self.validate_page_number(page_number)
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page_number += 1 # 1-base
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if page_number == self.pages:
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return self.hits
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if page_number == self.num_pages:
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return self.count
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return page_number * self.num_per_page
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def _get_hits(self):
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if self._hits is None:
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# Try .count() or fall back to len().
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def _get_count(self):
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# The old API allowed for self.object_list to be either a QuerySet or a
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# list. Here, we handle both.
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if self._count is None:
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try:
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self._hits = int(self.query_set.count())
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except (AttributeError, TypeError, ValueError):
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# AttributeError if query_set has no object count.
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# TypeError if query_set.count() required arguments.
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# ValueError if int() fails.
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self._hits = len(self.query_set)
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return self._hits
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self._count = self.object_list.count()
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except AttributeError:
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self._count = len(self.object_list)
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return self._count
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count = property(_get_count)
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def _get_pages(self):
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if self._pages is None:
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hits = (self.hits - 1 - self.orphans)
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if hits < 1:
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hits = 0
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self._pages = hits // self.num_per_page + 1
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return self._pages
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def _get_page_range(self):
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"""
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Returns a 1-based range of pages for iterating through within
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a template for loop.
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"""
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if self._page_range is None:
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self._page_range = range(1, self.pages + 1)
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return self._page_range
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# The old API called it "hits" instead of "count".
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hits = count
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hits = property(_get_hits)
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pages = property(_get_pages)
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page_range = property(_get_page_range)
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# The old API called it "pages" instead of "num_pages".
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pages = Paginator.num_pages
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@ -4,6 +4,11 @@
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Django provides a framework for paginating a list of objects in a few lines
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of code. This is often useful for dividing search results or long lists of
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objects into easily readable pages.
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In Django 0.96 and earlier, a single ObjectPaginator class implemented this
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functionality. In the Django development version, the behavior is split across
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two classes -- Paginator and Page -- that are more easier to use. The legacy
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ObjectPaginator class is deprecated.
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"""
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from django.db import models
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@ -16,70 +21,206 @@ class Article(models.Model):
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return self.headline
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__test__ = {'API_TESTS':"""
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# prepare a list of objects for pagination
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# Prepare a list of objects for pagination.
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>>> from datetime import datetime
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>>> for x in range(1, 10):
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... a = Article(headline='Article %s' % x, pub_date=datetime(2005, 7, 29))
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... a.save()
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# create a basic paginator, 5 articles per page
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####################################
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# New/current API (Paginator/Page) #
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####################################
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>>> from django.core.paginator import Paginator, InvalidPage
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>>> paginator = Paginator(Article.objects.all(), 5)
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>>> paginator.count
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9
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>>> paginator.num_pages
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2
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>>> paginator.page_range
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[1, 2]
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# Get the first page.
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>>> p = paginator.page(1)
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>>> p
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<Page 1 of 2>
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>>> p.object_list
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[<Article: Article 1>, <Article: Article 2>, <Article: Article 3>, <Article: Article 4>, <Article: Article 5>]
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>>> p.has_next()
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True
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>>> p.has_previous()
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False
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>>> p.has_other_pages()
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True
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>>> p.next_page_number()
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2
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>>> p.previous_page_number()
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0
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>>> p.start_index()
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1
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>>> p.end_index()
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5
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# Get the second page.
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>>> p = paginator.page(2)
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>>> p
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<Page 2 of 2>
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>>> p.object_list
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[<Article: Article 6>, <Article: Article 7>, <Article: Article 8>, <Article: Article 9>]
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>>> p.has_next()
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False
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>>> p.has_previous()
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True
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>>> p.has_other_pages()
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True
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>>> p.next_page_number()
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3
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>>> p.previous_page_number()
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1
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>>> p.start_index()
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6
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>>> p.end_index()
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9
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# Invalid pages raise InvalidPage.
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>>> paginator.page(0)
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Traceback (most recent call last):
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...
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InvalidPage: ...
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>>> paginator.page(3)
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Traceback (most recent call last):
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...
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InvalidPage: ...
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# Empty paginators with allow_empty_first_page=True.
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>>> paginator = Paginator(Article.objects.filter(id=0), 5, allow_empty_first_page=True)
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>>> paginator.count
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0
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>>> paginator.num_pages
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1
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>>> paginator.page_range
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[1]
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# Empty paginators with allow_empty_first_page=False.
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>>> paginator = Paginator(Article.objects.filter(id=0), 5, allow_empty_first_page=False)
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>>> paginator.count
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0
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>>> paginator.num_pages
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0
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>>> paginator.page_range
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[]
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# Paginators work with regular lists/tuples, too -- not just with QuerySets.
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>>> paginator = Paginator([1, 2, 3, 4, 5, 6, 7, 8, 9], 5)
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>>> paginator.count
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9
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>>> paginator.num_pages
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2
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>>> paginator.page_range
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[1, 2]
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# Get the first page.
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>>> p = paginator.page(1)
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>>> p
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<Page 1 of 2>
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>>> p.object_list
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[1, 2, 3, 4, 5]
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>>> p.has_next()
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True
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>>> p.has_previous()
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False
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>>> p.has_other_pages()
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True
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>>> p.next_page_number()
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2
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>>> p.previous_page_number()
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0
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>>> p.start_index()
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1
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>>> p.end_index()
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5
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################################
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# Legacy API (ObjectPaginator) #
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################################
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>>> from django.core.paginator import ObjectPaginator, InvalidPage
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>>> paginator = ObjectPaginator(Article.objects.all(), 5)
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# the paginator knows how many hits and pages it contains
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>>> paginator.hits
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9
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>>> paginator.pages
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2
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>>> paginator.page_range
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[1, 2]
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# get the first page (zero-based)
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# Get the first page.
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>>> paginator.get_page(0)
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[<Article: Article 1>, <Article: Article 2>, <Article: Article 3>, <Article: Article 4>, <Article: Article 5>]
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# get the second page
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>>> paginator.get_page(1)
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[<Article: Article 6>, <Article: Article 7>, <Article: Article 8>, <Article: Article 9>]
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# does the first page have a next or previous page?
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>>> paginator.has_next_page(0)
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True
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>>> paginator.has_previous_page(0)
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False
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# check the second page
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>>> paginator.has_next_page(1)
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False
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>>> paginator.has_previous_page(1)
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True
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>>> paginator.first_on_page(0)
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1
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>>> paginator.first_on_page(1)
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6
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>>> paginator.last_on_page(0)
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5
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# Get the second page.
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>>> paginator.get_page(1)
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[<Article: Article 6>, <Article: Article 7>, <Article: Article 8>, <Article: Article 9>]
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>>> paginator.has_next_page(1)
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False
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>>> paginator.has_previous_page(1)
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True
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>>> paginator.first_on_page(1)
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6
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>>> paginator.last_on_page(1)
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9
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# Invalid pages raise InvalidPage.
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>>> paginator.get_page(-1)
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Traceback (most recent call last):
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...
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InvalidPage: ...
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>>> paginator.get_page(2)
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Traceback (most recent call last):
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...
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InvalidPage: ...
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# Empty paginators with allow_empty_first_page=True.
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>>> paginator = ObjectPaginator(Article.objects.filter(id=0), 5)
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>>> paginator.count
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0
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>>> paginator.num_pages
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1
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>>> paginator.page_range
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[1]
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##################
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# Orphan support #
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##################
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# Add a few more records to test out the orphans feature.
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>>> for x in range(10, 13):
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... Article(headline="Article %s" % x, pub_date=datetime(2006, 10, 6)).save()
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# With orphans set to 3 and 10 items per page, we should get all 12 items on a single page:
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# With orphans set to 3 and 10 items per page, we should get all 12 items on a single page.
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>>> paginator = Paginator(Article.objects.all(), 10, orphans=3)
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>>> paginator.num_pages
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1
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# With orphans only set to 1, we should get two pages.
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>>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=1)
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>>> paginator.num_pages
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2
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# LEGACY: With orphans set to 3 and 10 items per page, we should get all 12 items on a single page.
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>>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=3)
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>>> paginator.pages
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1
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# With orphans only set to 1, we should get two pages:
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# LEGACY: With orphans only set to 1, we should get two pages.
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>>> paginator = ObjectPaginator(Article.objects.all(), 10, orphans=1)
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>>> paginator.pages
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2
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# The paginator can provide a list of all available pages.
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>>> paginator = ObjectPaginator(Article.objects.all(), 10)
|
||||
>>> paginator.page_range
|
||||
[1, 2]
|
||||
"""}
|
||||
|
|
|
|||
Loading…
Reference in New Issue