Fixed #14176 -- Added forwards compatibility to the legacy syndication feed view. This allows class-based feeds to be deployed using the old-style feed view, as long as the feed requires no arguments (i.e., get_object returns None). Thanks to psychcf for the report, cwhaines for the investigation, and Andrew Godwin for the assist.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15189 bcc190cf-cafb-0310-a4f2-bffc1f526a37

5 files changed, 79 insertions, 6 deletions

diff --git a/django/contrib/syndication/views.py b/django/contrib/syndication/views.py
index ee692e2c0c..9228e91687 100644
--- a/django/contrib/syndication/views.py
+++ b/django/contrib/syndication/views.py
@@ -188,6 +188,7 @@ class Feed(object):
 
 def feed(request, url, feed_dict=None):
     """Provided for backwards compatibility."""
+    from django.contrib.syndication.feeds import Feed as LegacyFeed
     import warnings
     warnings.warn('The syndication feed() view is deprecated. Please use the '
                   'new class based view API.',
@@ -206,6 +207,18 @@ def feed(request, url, feed_dict=None):
     except KeyError:
         raise Http404("Slug %r isn't registered." % slug)
 
+    # Backwards compatibility within the backwards compatibility;
+    # Feeds can be updated to be class-based, but still be deployed
+    # using the legacy feed view. This only works if the feed takes
+    # no arguments (i.e., get_object returns None). Refs #14176.
+    if not issubclass(f, LegacyFeed):
+        instance = f()
+        instance.feed_url = getattr(f, 'feed_url', None) or request.path
+        instance.title_template = f.title_template or ('feeds/%s_title.html' % slug)
+        instance.description_template = f.description_template or ('feeds/%s_description.html' % slug)
+
+        return instance(request)
+
     try:
         feedgen = f(slug, request).get_feed(param)
     except FeedDoesNotExist:
diff --git a/docs/ref/contrib/comments/example.txt b/docs/ref/contrib/comments/example.txt
index 424bdb13f5..921fe03ffa 100644
--- a/docs/ref/contrib/comments/example.txt
+++ b/docs/ref/contrib/comments/example.txt
@@ -143,19 +143,36 @@ enable it in your project's ``urls.py``:
   from django.conf.urls.defaults import *
   from django.contrib.comments.feeds import LatestCommentFeed
 
-  feeds = {
-      'latest': LatestCommentFeed,
-  }
-
   urlpatterns = patterns('',
   # ...
-      (r'^feeds/(?P<url>.*)/$', 'django.contrib.syndication.views.feed',
-          {'feed_dict': feeds}),
+      (r'^feeds/latest/$', LatestCommentFeed()),
   # ...
   )
 
 Now you should have the latest comment feeds being served off ``/feeds/latest/``.
 
+.. versionchanged:: 1.3
+
+Prior to Django 1.3, the LatestCommentFeed was deployed using the
+syndication feed view:
+
+.. code-block:: python
+
+    from django.conf.urls.defaults import *
+    from django.contrib.comments.feeds import LatestCommentFeed
+
+    feeds = {
+        'latest': LatestCommentFeed,
+    }
+
+    urlpatterns = patterns('',
+    # ...
+        (r'^feeds/(?P<url>.*)/$', 'django.contrib.syndication.views.feed',
+            {'feed_dict': feeds}),
+    # ...
+    )
+
+
 Moderation
 ==========
 
diff --git a/tests/regressiontests/comment_tests/tests/__init__.py b/tests/regressiontests/comment_tests/tests/__init__.py
index 449fea471d..88c6f33203 100644
--- a/tests/regressiontests/comment_tests/tests/__init__.py
+++ b/tests/regressiontests/comment_tests/tests/__init__.py
@@ -81,6 +81,7 @@ class CommentTestCase(TestCase):
         return d
 
 from regressiontests.comment_tests.tests.app_api_tests import *
+from regressiontests.comment_tests.tests.feed_tests import *
 from regressiontests.comment_tests.tests.model_tests import *
 from regressiontests.comment_tests.tests.comment_form_tests import *
 from regressiontests.comment_tests.tests.templatetag_tests import *
diff --git a/tests/regressiontests/comment_tests/tests/feed_tests.py b/tests/regressiontests/comment_tests/tests/feed_tests.py
new file mode 100644
index 0000000000..0bc6618d9a
--- /dev/null
+++ b/tests/regressiontests/comment_tests/tests/feed_tests.py
@@ -0,0 +1,33 @@
+import warnings
+
+from django.test.utils import get_warnings_state, restore_warnings_state
+
+from regressiontests.comment_tests.tests import CommentTestCase
+
+
+class CommentFeedTests(CommentTestCase):
+    urls = 'regressiontests.comment_tests.urls'
+    feed_url = '/rss/comments/'
+
+    def test_feed(self):
+        response = self.client.get(self.feed_url)
+        self.assertEquals(response.status_code, 200)
+        self.assertEquals(response['Content-Type'], 'application/rss+xml')
+        self.assertContains(response, '<rss xmlns:atom="http://www.w3.org/2005/Atom" version="2.0">')
+        self.assertContains(response, '<title>example.com comments</title>')
+        self.assertContains(response, '<link>http://example.com/</link>')
+        self.assertContains(response, '</rss>')
+
+
+class LegacyCommentFeedTests(CommentFeedTests):
+    feed_url = '/rss/legacy/comments/'
+
+    def setUp(self):
+        self._warnings_state = get_warnings_state()
+        warnings.filterwarnings("ignore", category=DeprecationWarning,
+                                module='django.contrib.syndication.views')
+        warnings.filterwarnings("ignore", category=DeprecationWarning,
+                                module='django.contrib.syndication.feeds')
+
+    def tearDown(self):
+        restore_warnings_state(self._warnings_state)
diff --git a/tests/regressiontests/comment_tests/urls.py b/tests/regressiontests/comment_tests/urls.py
index 0058689657..052f7cf81d 100644
--- a/tests/regressiontests/comment_tests/urls.py
+++ b/tests/regressiontests/comment_tests/urls.py
@@ -1,4 +1,9 @@
 from django.conf.urls.defaults import *
+from django.contrib.comments.feeds import LatestCommentFeed
+
+feeds = {
+     'comments': LatestCommentFeed,
+}
 
 urlpatterns = patterns('regressiontests.comment_tests.custom_comments.views',
     url(r'^post/$',          'custom_submit_comment'),
@@ -7,3 +12,7 @@ urlpatterns = patterns('regressiontests.comment_tests.custom_comments.views',
     url(r'^approve/(\d+)/$', 'custom_approve_comment'),
 )
 
+urlpatterns += patterns('',
+    (r'^rss/legacy/(?P<url>.*)/$', 'django.contrib.syndication.views.feed', {'feed_dict': feeds}),
+    (r'^rss/comments/$', LatestCommentFeed()),
+)