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/'):
+ """
+ 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)
+ 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."
+ """
+ Validates the given 1-based page number.
+ """
try:
number = int(number)
except ValueError:
return number
def page(self, number):
- "Returns a Page object for the given 1-based page 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
return InfinitePage(page_items, number, self)
def _get_count(self):
- "Returns the total number of objects, across all pages."
+ """
+ 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."
+ """
+ Returns the total number of pages.
+ """
raise NotImplementedError
num_pages = property(_get_num_pages)
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."
+ """
+ Checks for one more item than last on this page.
+ """
try:
- next_item = self.paginator.object_list[self.number * self.paginator.per_page]
+ next_item = self.paginator.object_list[
+ self.number * self.paginator.per_page]
except IndexError:
return False
return True
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'''
+ 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():
def previous_link(self):
if self.has_previous():
return self.paginator.link_template % (self.number - 1)
- return None
\ No newline at end of file
+ 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