Added better error handling in the basic feed class example. Refs #5855

git-svn-id: http://code.djangoproject.com/svn/django/trunk@6741 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Malcolm Tredinnick 2007-11-29 17:41:35 +00:00
parent d94ed44c5d
commit f86e54e3b0
1 changed files with 13 additions and 2 deletions

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@ -201,6 +201,8 @@ the feed.
An example makes this clear. Here's the code for these beat-specific feeds::
from django.contrib.syndication import FeedDoesNotExist
class BeatFeed(Feed):
def get_object(self, bits):
# In case of "/rss/beats/0613/foo/bar/baz/", or other such clutter,
@ -213,6 +215,8 @@ An example makes this clear. Here's the code for these beat-specific feeds::
return "Chicagocrime.org: Crimes for beat %s" % obj.beat
def link(self, obj):
if not obj:
raise FeedDoesNotExist
return obj.get_absolute_url()
def description(self, obj):
@ -246,11 +250,18 @@ request to the URL ``/rss/beats/0613/``:
each of ``title``, ``link`` and ``description``, Django follows this
algorithm:
* First, it tries to call a method, passing the ``obj`` argument, where
``obj`` is the object returned by ``get_object()``.
* First, it tries to call a method, passing the ``obj`` argument,
where ``obj`` is the object returned by ``get_object()``.
* Failing that, it tries to call a method with no arguments.
* Failing that, it uses the class attribute.
Inside the ``link()`` method, we handle the possibility that ``obj``
might be ``None``, which can occur when the URL isn't fully specified. In
some cases, you might want to do something else in this case, which would
mean you'd need to check for ``obj`` existing in other methods as well
(the ``link()`` method is called very early in the feed generation
process, so is a good place to bail out early).
* Finally, note that ``items()`` in this example also takes the ``obj``
argument. The algorithm for ``items`` is the same as described in the
previous step -- first, it tries ``items(obj)``, then ``items()``, then