@@ 0,0 1,151 @@
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.
Class name is pronounced verbally in a deep tone.
'''
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:
next_item = 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:
next_item = 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
\ No newline at end of file
@@ 58,4 58,74 @@ u'\\n\\n<div class="pagination">...
>>> t.render(Context({'var': range(21), 'by': 20, 'request': RequestProxy()}))
u'[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]'
>>>
# Testing InfinitePaginator
>>> from paginator import InfinitePaginator
>>> InfinitePaginator
<class 'pagination.paginator.InfinitePaginator'>
>>> p = InfinitePaginator(range(20), 2, link_template='/bacon/page/%d')
>>> p.validate_number(2)
2
>>> p.orphans
0
>>> p3 = p.page(3)
>>> p3
<Page 3>
>>> p3.end_index()
6
>>> p3.has_next()
True
>>> p3.has_previous()
True
>>> p.page(10).has_next()
False
>>> p.page(1).has_previous()
False
>>> p3.next_link()
'/bacon/page/4'
>>> p3.previous_link()
'/bacon/page/2'
# Testing FinitePaginator
>>> from paginator import FinitePaginator
>>> FinitePaginator
<class 'pagination.paginator.FinitePaginator'>
>>> p = FinitePaginator(range(20), 2, offset=10, link_template='/bacon/page/%d')
>>> p.validate_number(2)
2
>>> p.orphans
0
>>> p3 = p.page(3)
>>> p3
<Page 3>
>>> p3.start_index()
10
>>> p3.end_index()
6
>>> p3.has_next()
True
>>> p3.has_previous()
True
>>> p3.next_link()
'/bacon/page/4'
>>> p3.previous_link()
'/bacon/page/2'
>>> p = FinitePaginator(range(20), 20, offset=10, link_template='/bacon/page/%d')
>>> p2 = p.page(2)
>>> p2
<Page 2>
>>> p2.has_next()
False
>>> p3.has_previous()
True
>>> p2.next_link()
>>> p2.previous_link()
'/bacon/page/1'
"""
\ No newline at end of file