--- /dev/null
+# Copyright (c) 2008, Eric Florenzano
+# Copyright (c) 2010, 2011 Linaro Limited
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following
+# disclaimer in the documentation and/or other materials provided
+# with the distribution.
+# * Neither the name of the author nor the names of other
+# contributors may be used to endorse or promote products derived
+# from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+from django.core.paginator import Paginator, Page, PageNotAnInteger, EmptyPage
+
+
+class InfinitePaginator(Paginator):
+ """
+ Paginator designed for cases when it's not important to know how many total
+ pages. This is useful for any object_list that has no count() method or
+ can be used to improve performance for MySQL by removing counts.
+
+ The orphans parameter has been removed for simplicity and there's a link
+ template string for creating the links to the next and previous pages.
+ """
+
+ def __init__(self, object_list, per_page, allow_empty_first_page=True,
+ link_template='/page/%d/'):
+ orphans = 0 # no orphans
+ super(InfinitePaginator, self).__init__(object_list, per_page, orphans,
+ allow_empty_first_page)
+ # no count or num pages
+ del self._num_pages, self._count
+ # bonus links
+ self.link_template = link_template
+
+ def validate_number(self, number):
+ """
+ Validates the given 1-based page number.
+ """
+ try:
+ number = int(number)
+ except ValueError:
+ raise PageNotAnInteger('That page number is not an integer')
+ if number < 1:
+ raise EmptyPage('That page number is less than 1')
+ return number
+
+ def page(self, number):
+ """
+ Returns a Page object for the given 1-based page number.
+ """
+ number = self.validate_number(number)
+ bottom = (number - 1) * self.per_page
+ top = bottom + self.per_page
+ page_items = self.object_list[bottom:top]
+ # check moved from validate_number
+ if not page_items:
+ if number == 1 and self.allow_empty_first_page:
+ pass
+ else:
+ raise EmptyPage('That page contains no results')
+ return InfinitePage(page_items, number, self)
+
+ def _get_count(self):
+ """
+ Returns the total number of objects, across all pages.
+ """
+ raise NotImplementedError
+ count = property(_get_count)
+
+ def _get_num_pages(self):
+ """
+ Returns the total number of pages.
+ """
+ raise NotImplementedError
+ num_pages = property(_get_num_pages)
+
+ def _get_page_range(self):
+ """
+ Returns a 1-based range of pages for iterating through within
+ a template for loop.
+ """
+ raise NotImplementedError
+ page_range = property(_get_page_range)
+
+
+class InfinitePage(Page):
+
+ def __repr__(self):
+ return '<Page %s>' % self.number
+
+ def has_next(self):
+ """
+ Checks for one more item than last on this page.
+ """
+ try:
+ self.paginator.object_list[self.number * self.paginator.per_page]
+ except IndexError:
+ return False
+ return True
+
+ def end_index(self):
+ """
+ Returns the 1-based index of the last object on this page,
+ relative to total objects found (hits).
+ """
+ return ((self.number - 1) * self.paginator.per_page +
+ len(self.object_list))
+
+ #Bonus methods for creating links
+
+ def next_link(self):
+ if self.has_next():
+ return self.paginator.link_template % (self.number + 1)
+ return None
+
+ def previous_link(self):
+ if self.has_previous():
+ return self.paginator.link_template % (self.number - 1)
+ return None
+
+
+class FinitePaginator(InfinitePaginator):
+ """
+ Paginator for cases when the list of items is already finite.
+
+ A good example is a list generated from an API call. This is a subclass
+ of InfinitePaginator because we have no idea how many items exist in the
+ full collection.
+
+ To accurately determine if the next page exists, a FinitePaginator MUST be
+ created with an object_list_plus that may contain more items than the
+ per_page count. Typically, you'll have an object_list_plus with one extra
+ item (if there's a next page). You'll also need to supply the offset from
+ the full collection in order to get the page start_index.
+
+ This is a very silly class but useful if you love the Django pagination
+ conventions.
+ """
+
+ def __init__(self, object_list_plus, per_page, offset=None,
+ allow_empty_first_page=True, link_template='/page/%d/'):
+ super(FinitePaginator, self).__init__(object_list_plus, per_page,
+ allow_empty_first_page, link_template)
+ self.offset = offset
+
+ def validate_number(self, number):
+ super(FinitePaginator, self).validate_number(number)
+ # check for an empty list to see if the page exists
+ if not self.object_list:
+ if number == 1 and self.allow_empty_first_page:
+ pass
+ else:
+ raise EmptyPage('That page contains no results')
+ return number
+
+ def page(self, number):
+ """
+ Returns a Page object for the given 1-based page number.
+ """
+ number = self.validate_number(number)
+ # remove the extra item(s) when creating the page
+ page_items = self.object_list[:self.per_page]
+ return FinitePage(page_items, number, self)
+
+
+class FinitePage(InfinitePage):
+
+ def has_next(self):
+ """
+ Checks for one more item than last on this page.
+ """
+ try:
+ self.paginator.object_list[self.paginator.per_page]
+ except IndexError:
+ return False
+ return True
+
+ def start_index(self):
+ """
+ Returns the 1-based index of the first object on this page,
+ relative to total objects in the paginator.
+ """
+ ## TODO should this holler if you haven't defined the offset?
+ return self.paginator.offset
fnp / django-pagination.git / blobdiff