On Thu, Nov 12, 2009 at 3:55 PM, Herbert Van de Sompel
<hvdsomp(a)gmail.com> wrote:
2.1. The plug-in detects a client's
X-Accept-Datetime header, and
returns the mediawiki page that was active at the datetime specified
in the header. Same for images, actually. This effectively allows
navigating (as in clicking links) a mediawiki collection as it existed
in the past: as long as a client issues an X-Accept-Datetime header,
matching history pages/images will be retrieved.
Doesn't the use of a header here violate the idea of each URL
representing only one resource? The server will be returning totally
different things for a GET to the same URL. That seems like it would
cause all sorts of problems -- not only do caching proxies break
(which I'd think by itself makes the feature unusable for users behind
caching proxies), but how do you deal with things like bookmarking, or
sending a link to a particular version of the page to someone? These
would become impossible, unless the server goes to the extra effort to
return a redirect.
It seems to me like a better path would be to have different URLs for
different dates. The obvious way to do this would be to take an
approach like OpenSearch, and provide a URL pattern in some standard
format. Maybe the page could contain <link rel=oldversions> or such,
with the client appending a query parameter to the given URL, say
time=T where T is an ISO 8601 string.