Fixed #16218 -- date_list order in generic CBVs.

Thanks nnrcschmdt for the report and bpeschier for the initial
version of the patch.

django/views/generic/dates.py

@@ -377,7 +377,7 @@ class BaseDateListView(MultipleObjectMixin, DateMixin, View):
         """
         return self.date_list_period
 
-    def get_date_list(self, queryset, date_type=None):
+    def get_date_list(self, queryset, date_type=None, ordering='ASC'):
         """
         Get a date list by calling `queryset.dates()`, checking along the way
         for empty lists that aren't allowed.
@@ -387,7 +387,7 @@ class BaseDateListView(MultipleObjectMixin, DateMixin, View):
         if date_type is None:
             date_type = self.get_date_list_period()
 
-        date_list = queryset.dates(date_field, date_type)[::-1]
+        date_list = queryset.dates(date_field, date_type, ordering)
         if date_list is not None and not date_list and not allow_empty:
             name = force_text(queryset.model._meta.verbose_name_plural)
             raise Http404(_("No %(verbose_name_plural)s available") %
@@ -409,7 +409,7 @@ class BaseArchiveIndexView(BaseDateListView):
         Return (date_list, items, extra_context) for this request.
         """
         qs = self.get_dated_queryset(ordering='-%s' % self.get_date_field())
-        date_list = self.get_date_list(qs)
+        date_list = self.get_date_list(qs, ordering='DESC')
 
         if not date_list:
             qs = qs.none()

docs/ref/class-based-views/mixins-date-based.txt

@@ -318,12 +318,16 @@ BaseDateListView
         Returns the aggregation period for ``date_list``. Returns
         :attr:`~BaseDateListView.date_list_period` by default.
 
-    .. method:: get_date_list(queryset, date_type=None)
+    .. method:: get_date_list(queryset, date_type=None, ordering='ASC')
 
         Returns the list of dates of type ``date_type`` for which ``queryset``
         contains entries. For example, ``get_date_list(qs, 'year')`` will
         return the list of years for which ``qs`` has entries. If
         ``date_type`` isn't provided, the result of
-        :meth:`BaseDateListView.get_date_list_period` is used. See
-        :meth:`~django.db.models.query.QuerySet.dates()` for the ways that the
-        ``date_type`` argument can be used.
+        :meth:`~BaseDateListView.get_date_list_period` is used. ``date_type``
+        and ``ordering`` are simply passed to
+        :meth:`QuerySet.dates()<django.db.models.query.QuerySet.dates>`.
+
+        .. versionchanged:: 1.5
+            The ``ordering`` parameter was added, and the default order was
+            changed to ascending.

docs/releases/1.5.txt

@@ -152,6 +152,21 @@ year|date:"Y" }}``.
 ``next_year`` and ``previous_year`` were also added in the context. They are
 calculated according to ``allow_empty`` and ``allow_future``.
 
+Context in year and month archive class-based views
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+:class:`~django.views.generic.dates.YearArchiveView` and
+:class:`~django.views.generic.dates.MonthArchiveView` were documented to
+provide a ``date_list`` sorted in ascending order in the context, like their
+function-based predecessors, but it actually was in descending order. In 1.5,
+the documented order was restored. You may want to add (or remove) the
+``reversed`` keyword when you're iterating on ``date_list`` in a template::
+
+    {% for date in date_list reversed %}
+
+:class:`~django.views.generic.dates.ArchiveIndexView` still provides a
+``date_list`` in descending order.
+
 Context in TemplateView
 ~~~~~~~~~~~~~~~~~~~~~~~
 

tests/regressiontests/generic_views/dates.py

@@ -23,29 +23,30 @@ requires_tz_support = skipUnless(TZ_SUPPORT,
         "time zone, but your operating system isn't able to do that.")
 
 
+def _make_books(n, base_date):
+    for i in range(n):
+        b = Book.objects.create(
+            name='Book %d' % i,
+            slug='book-%d' % i,
+            pages=100+i,
+            pubdate=base_date - datetime.timedelta(days=i))
+
 class ArchiveIndexViewTests(TestCase):
     fixtures = ['generic-views-test-data.json']
     urls = 'regressiontests.generic_views.urls'
 
-    def _make_books(self, n, base_date):
-        for i in range(n):
-            b = Book.objects.create(
-                name='Book %d' % i,
-                slug='book-%d' % i,
-                pages=100+i,
-                pubdate=base_date - datetime.timedelta(days=1))
 
     def test_archive_view(self):
         res = self.client.get('/dates/books/')
         self.assertEqual(res.status_code, 200)
-        self.assertEqual(res.context['date_list'], Book.objects.dates('pubdate', 'year')[::-1])
+        self.assertEqual(list(res.context['date_list']), list(Book.objects.dates('pubdate', 'year', 'DESC')))
         self.assertEqual(list(res.context['latest']), list(Book.objects.all()))
         self.assertTemplateUsed(res, 'generic_views/book_archive.html')
 
     def test_archive_view_context_object_name(self):
         res = self.client.get('/dates/books/context_object_name/')
         self.assertEqual(res.status_code, 200)
-        self.assertEqual(res.context['date_list'], Book.objects.dates('pubdate', 'year')[::-1])
+        self.assertEqual(list(res.context['date_list']), list(Book.objects.dates('pubdate', 'year', 'DESC')))
         self.assertEqual(list(res.context['thingies']), list(Book.objects.all()))
         self.assertFalse('latest' in res.context)
         self.assertTemplateUsed(res, 'generic_views/book_archive.html')
@@ -65,14 +66,14 @@ class ArchiveIndexViewTests(TestCase):
     def test_archive_view_template(self):
         res = self.client.get('/dates/books/template_name/')
         self.assertEqual(res.status_code, 200)
-        self.assertEqual(res.context['date_list'], Book.objects.dates('pubdate', 'year')[::-1])
+        self.assertEqual(list(res.context['date_list']), list(Book.objects.dates('pubdate', 'year', 'DESC')))
         self.assertEqual(list(res.context['latest']), list(Book.objects.all()))
         self.assertTemplateUsed(res, 'generic_views/list.html')
 
     def test_archive_view_template_suffix(self):
         res = self.client.get('/dates/books/template_name_suffix/')
         self.assertEqual(res.status_code, 200)
-        self.assertEqual(res.context['date_list'], Book.objects.dates('pubdate', 'year')[::-1])
+        self.assertEqual(list(res.context['date_list']), list(Book.objects.dates('pubdate', 'year', 'DESC')))
         self.assertEqual(list(res.context['latest']), list(Book.objects.all()))
         self.assertTemplateUsed(res, 'generic_views/book_detail.html')
 
@@ -82,13 +83,13 @@ class ArchiveIndexViewTests(TestCase):
     def test_archive_view_by_month(self):
         res = self.client.get('/dates/books/by_month/')
         self.assertEqual(res.status_code, 200)
-        self.assertEqual(res.context['date_list'], Book.objects.dates('pubdate', 'month')[::-1])
+        self.assertEqual(list(res.context['date_list']), list(Book.objects.dates('pubdate', 'month', 'DESC')))
 
     def test_paginated_archive_view(self):
-        self._make_books(20, base_date=datetime.date.today())
+        _make_books(20, base_date=datetime.date.today())
         res = self.client.get('/dates/books/paginated/')
         self.assertEqual(res.status_code, 200)
-        self.assertEqual(res.context['date_list'], Book.objects.dates('pubdate', 'year')[::-1])
+        self.assertEqual(list(res.context['date_list']), list(Book.objects.dates('pubdate', 'year', 'DESC')))
         self.assertEqual(list(res.context['latest']), list(Book.objects.all()[0:10]))
         self.assertTemplateUsed(res, 'generic_views/book_archive.html')
 
@@ -99,7 +100,7 @@ class ArchiveIndexViewTests(TestCase):
 
     def test_paginated_archive_view_does_not_load_entire_table(self):
         # Regression test for #18087
-        self._make_books(20, base_date=datetime.date.today())
+        _make_books(20, base_date=datetime.date.today())
         # 1 query for years list + 1 query for books
         with self.assertNumQueries(2):
             self.client.get('/dates/books/')
@@ -124,6 +125,13 @@ class ArchiveIndexViewTests(TestCase):
         res = self.client.get('/dates/booksignings/')
         self.assertEqual(res.status_code, 200)
 
+    def test_date_list_order(self):
+        """date_list should be sorted descending in index"""
+        _make_books(5, base_date=datetime.date(2011, 12, 25))
+        res = self.client.get('/dates/books/')
+        self.assertEqual(res.status_code, 200)
+        self.assertEqual(list(res.context['date_list']), list(reversed(sorted(res.context['date_list']))))
+
 
 class YearArchiveViewTests(TestCase):
     fixtures = ['generic-views-test-data.json']
@@ -202,6 +210,12 @@ class YearArchiveViewTests(TestCase):
         res = self.client.get('/dates/booksignings/2008/')
         self.assertEqual(res.status_code, 200)
 
+    def test_date_list_order(self):
+        """date_list should be sorted ascending in year view"""
+        _make_books(10, base_date=datetime.date(2011, 12, 25))
+        res = self.client.get('/dates/books/2011/')
+        self.assertEqual(list(res.context['date_list']), list(sorted(res.context['date_list'])))
+
 
 class MonthArchiveViewTests(TestCase):
     fixtures = ['generic-views-test-data.json']
@@ -322,6 +336,12 @@ class MonthArchiveViewTests(TestCase):
         res = self.client.get('/dates/booksignings/2008/apr/')
         self.assertEqual(res.status_code, 200)
 
+    def test_date_list_order(self):
+        """date_list should be sorted ascending in month view"""
+        _make_books(10, base_date=datetime.date(2011, 12, 25))
+        res = self.client.get('/dates/books/2011/dec/')
+        self.assertEqual(list(res.context['date_list']), list(sorted(res.context['date_list'])))
+
 
 class WeekArchiveViewTests(TestCase):
     fixtures = ['generic-views-test-data.json']