Genii Weblog

Why doesn't RSS use a selective poll technology?

Thu 5 Jan 2006, 11:55 PM



by Ben Langhinrichs
One of the things that bugs me about RSS feeds is that they are a pull technology (instead of a push), but don't use of the classic advantages of pull technology, which is the ability to be selective.  It seems like it would be incredibly easy to add a parameter or two to the request to filter the results.  For example, the RSS feed for this weblog is:

BlogStories.xml

but since this is a Domino RSS feed, why not allow you to select a bit more, such as:

BlogStories.xml&OpenAgent&Comments=Yes

and comments would be included, or

BlogStories.xml&OpenAgent&Category=Lotusphere

and only subjects in the Lotusphere category would be returned.  Likewise, you could use:

BlogStories.xml&OpenAgent&Cutoff=2006-01-05

and only topics after the cutoff date would be returned.  But why bother, you may ask?  Well, here is what led me to this.  Christopher Linfoot made a request about the new RSS feeds that have been added to the Lotus LDD forums, which is that comments be separated into a separate feed, as the volume is too extreme the way it is now.  But I hate comments in a separate feed.  So it occurred to me, why not only give main topics by default, but add a hotspot on each main topic that says "Pull in thread", and then the default:

http://www-10.lotus.com/ldd/nd6forum.nsf/forumfeed.rss

could be replaced by something like:

http://www-10.lotus.com/ldd/nd6forum.nsf/forumfeed.rss?OpenAgent&ParentUNID=cc8952b68d4ea683852570ed0040edc2

which would pull in that whole thread.  The RSS readers could handle the variability now in most cases, as they don't get rid of old content just because it is not in the feed, and they don't duplicate posts, so the thread would simply be populated.  This seems to me like the best of both worlds.  Have I missed something, or could we propose this?

Copyright © 2006 Genii Software Ltd.

What has been said:


419.1. Declan Lynch (01/05/2006 10:35 PM)

some work on this has already been done about 2 years ago but it never gained a foothold in the RSS Readers.

Using namespaces in the RSS 2.0 spec you can add a 'comment count' and 'comments feed'. The reader then displays the count, can figure out if there are new comments based on the last time it pulled the feed and also display a 'pull comments' type link.

The only reader that I know that supports this is Sharpreader. The feeds generated by BlogSphere include the extra comment count and feed info. I'm not sure about DominoBlog's RSS feeds, if Steve reads this maybe he can let us know.


419.2. Rob McDonagh (01/06/2006 11:08 AM)

I'm not a huge fan of comments feeds, either. I use them, but only because I have no choice. I would MUCH rather have the posts and comments threaded, a la the Notes (and usenet) model. I've seen the arguments about how threaded vs non-threaded discussions produce different conversation flows, but as the *consumer* of the information I want to see the threads.

When I saw the RSS feeds for LDD, my initial reaction was to wonder how I could possibly keep up with which comments related to which post on a feed that large. I have enough trouble with higher traffic blogs, especially when people change the subject line and remove the reference to the original post. So I haven't subscribed to the feeds, and I don't expect to in the future.

As Dec points out, Sharpreader's threaded comment support is pretty...um...sharp. I wish more RSS readers included it.