RE: Refering to versions
I think the argument is more fundamental. The feeling is that URLs point to
a single resource. While a resource may have several representations each
representation is a semantically equivalent, although possibly degraded,
version of each other. Two different versions of a document are not
semantically equivalent. While one could make an argument along the lines
of "degraded" content, I don't think the argument is very compelling. So
Henrik and others are arguing that we should specify version as part of the
URL because we are referring to related but distinct resources.
From: Dale Gass [SMTP:firstname.lastname@example.org]
Sent: Monday, October 28, 1996 12:55 PM
To: Yaron Goland
Subject: Re: Refering to versions
> I do not believe that URL kludge is the way to go. Rather we need a
> header. Just as one can negotiate on language or content type, one will
> able to use a version header to negotiate on version.
(Sorry if some of this is naive or has been covered before; I haven't had
time to follow this list too closely.)
I had mixed feelings on this; headers do seem cleaner, URL's seem to work
better within existing browsers. (Actually, it's not a matter of them
working better, it's a matter of them working at all; using headers to
specify the version makes going to a specific header via a link impossible
in any existing browser).
Perhaps what we need is to encourage the browser manufacturers or HTTP
standards folk to develop extensions to HTTP to allow specification of
versions in links:
<A HREF="http://www.mks.com/some/path/index.htm" VERSION=1.3>...
or perhaps something more generic, equivalent to the
HTTP Response header of the <META> tag:
The browsers would follow this link and insert a "Version: 1.3" header
in the request.
This would be a much cleaner approach all-round than the URL munging,
it has a serious problem of requiring Browser support. I think the second
option above (allowing adding an aribtrary header to a link) would have
<A HREF="http://www.mks.com/NewStuff.htm HTTP-EQUIV="Pragma"
Always load this page, never use cached.</A>
<A HREF="http://www.mks.com/Secret.htm HTTP-EQUIV="Authorization"
CONTENT="basic zcvzckjdfzkdjfzd">Go to secure page</A>
<A HREF="http://www.mks.com/International.htm HTTP-EQUIV="Accept-Language"
CONTENT="French">Get the french version</A>
and so forth...
Specifically for versioning, it would allow a great deal of flexibility
no only for a Version: header, but for other related headers which would