Daniel Kinzler wrote:
Hi all
The Memento Project <http://www.mementoweb.org/> (including the Los Alamos
National Laboratory (!) featuring Herbert Van de Sompel of OpenURL fame) is
proposing a new HTTP header, X-Accept-Datetime, to fetch old versions of a web
resource. They already wrote a MediaWiki extension for this
<http://www.mediawiki.org/wiki/Extension:Memento> - which would of course be
particularly interesting for use on Wikipedia.
Do you think we could have this for Wikimedia project? I think that would be
very nice indeed. I recall that ways to look at last weeks main page have been
discussed before, and I see several issues:
* the timestamp isn't a unique identifier, multiple revisions *might* have the
same timestamp. We need a tiebreak (rev_id would be the obvious choice).
* templates and images also need to be "time warped". It seems like the
extension does not address this at the moment. For flagged revisions we do have
such a machnism, right? Could that be used here?
* Squids would need to know about the new header, and by pass the cache when
it's used.
You can't view the main page as it was in the past, because users
routinely upload temporary images to display there, so that they can
be protected, and then delete them once they're off the page.
Also, we can't have people crawling Wikipedia while requesting old
versions, because of the excessive disk seeking and CPU usage that
would generate. That's why the history page has a robot policy of
noindex, nofollow.
-- Tim Starling