Commit fbfa654a authored by Chris Beaven's avatar Chris Beaven
Browse files

Paginator._get_page hook 

This allows for Paginator subclasses to easily override the Page class
that gets used.

Took the opportunity to also do some non-invasive PEP8 tidying of the
paginator module.
parent 8fdb2821

django/core/paginator.py

+32 −7
Original line number Diff line number Diff line
@@ -7,14 +7,19 @@ from django.utils import six 
class InvalidPage(Exception):

    pass





class PageNotAnInteger(InvalidPage):

    pass





class EmptyPage(InvalidPage):

    pass





class Paginator(object):

    def __init__(self, object_list, per_page, orphans=0, allow_empty_first_page=True):



    def __init__(self, object_list, per_page, orphans=0,

                 allow_empty_first_page=True):

        self.object_list = object_list

        self.per_page = int(per_page)

        self.orphans = int(orphans)
@@ -22,7 +27,9 @@ class Paginator(object): 
        self._num_pages = self._count = None



    def validate_number(self, number):

        "Validates the given 1-based page number."

        """

        Validates the given 1-based page number.

        """

        try:

            number = int(number)

        except (TypeError, ValueError):
@@ -37,16 +44,29 @@ class Paginator(object): 
        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

        if top + self.orphans >= self.count:

            top = self.count

        return Page(self.object_list[bottom:top], number, self)

        return self._get_page(self.object_list[bottom:top], number, self)



    def _get_page(self, *args, **kwargs):

        """

        Returns an instance of a single page.



        This hook can be used by subclasses to use an alternative to the

        standard :cls:`Page` object.

        """

        return Page(*args, **kwargs)



    def _get_count(self):

        "Returns the total number of objects, across all pages."

        """

        Returns the total number of objects, across all pages.

        """

        if self._count is None:

            try:

                self._count = self.object_list.count()
@@ -59,7 +79,9 @@ class Paginator(object): 
    count = property(_get_count)



    def _get_num_pages(self):

        "Returns the total number of pages."

        """

        Returns the total number of pages.

        """

        if self._num_pages is None:

            if self.count == 0 and not self.allow_empty_first_page:

                self._num_pages = 0
@@ -77,9 +99,12 @@ class Paginator(object): 
        return range(1, self.num_pages + 1)

    page_range = property(_get_page_range)





QuerySetPaginator = Paginator   # For backwards-compatibility.





class Page(collections.Sequence):



    def __init__(self, object_list, number, paginator):

        self.object_list = object_list

        self.number = number

tests/regressiontests/pagination/custom.py

0 → 100644
+20 −0
Original line number Diff line number Diff line 
from django.core.paginator import Paginator, Page





class ValidAdjacentNumsPage(Page):



    def next_page_number(self):

        if not self.has_next():

            return None

        return super(ValidAdjacentNumsPage, self).next_page_number()



    def previous_page_number(self):

        if not self.has_previous():

            return None

        return super(ValidAdjacentNumsPage, self).previous_page_number()





class ValidAdjacentNumsPaginator(Paginator):



    def _get_page(self, *args, **kwargs):

        return ValidAdjacentNumsPage(*args, **kwargs)

tests/regressiontests/pagination/tests.py

+15 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ from django.utils import six 
from django.utils import unittest



from .models import Article

from .custom import ValidAdjacentNumsPaginator





class PaginationTests(unittest.TestCase):
@@ -217,6 +218,20 @@ class PaginationTests(unittest.TestCase): 
        self.assertEqual(''.join(page2), 'fghijk')

        self.assertEqual(''.join(reversed(page2)), 'kjihgf')



    def test_get_page_hook(self):

        """

        Tests that a Paginator subclass can use the ``_get_page`` hook to

        return an alternative to the standard Page class.

        """

        eleven = 'abcdefghijk'

        paginator = ValidAdjacentNumsPaginator(eleven, per_page=6)

        page1 = paginator.page(1)

        page2 = paginator.page(2)

        self.assertEquals(page1.previous_page_number(), None)

        self.assertEquals(page1.next_page_number(), 2)

        self.assertEquals(page2.previous_page_number(), 1)

        self.assertEquals(page2.next_page_number(), None)





class ModelPaginationTests(TestCase):

    """