Next message: Tim_Ellison@uk.ibm.com: "XML attribute"
From: Tim_Ellison@uk.ibm.com
To: ietf-dav-versioning@w3.org
Message-ID: <8025695E.004E09F8.00@d06mta07.portsmouth.uk.ibm.com>
Date: Mon, 18 Sep 2000 15:12:19 +0100
Subject: RE: Naive question
Whoops, sent to Geoff privately, instead of the list...
Geoff did respond very timely as usual, but I'll let him post his own
public response to the list.
Tim
---------------------- Forwarded by Tim Ellison/UK/IBM on 2000-09-18 03:11
PM ---------------------------
Tim Ellison
2000-09-14 09:50 AM
To: "Clemm, Geoff" <gclemm@rational.com>
cc:
From: Tim Ellison/UK/IBM@IBMGB
Subject: RE: Naive question (Document link: Tim Ellison)
<tim>
If I think of the version selector as a copy of the version (content and
dead properties) it selects then maybe it makes a bit more sense. The live
properties were not copied so you don't see them in the version selector,
and there is no call for a 'metadata' type header.
</tim>
<geoff>
Yes, that's a better model. But note that you do not have to *implement*
it as a copy, i.e. you can just redirect back to the version to get the
content or dead properties from there.
</geoff>
<tim_2/> Of course, it's just how I would think about it.
<tim>
But now there is no resource that is a version selector (it is just a copy)
</tim>
<geoff>
Why is a copy not a resource? In fact, that's the difference between COPY
and MOVE ... COPY creates a new resource, while MOVE just renames an
existing resource.
</geoff>
<tim_2>
Oh it would be a resource, but it would be the same type of resource as the
source of the copy. It would not be a 'version selector' resource.
Maybe if 'version selector' and 'working resource' were described as
"states" of existing resources rather than resources themselves.
</tim_2>
<snip>
<tim/>If someone could attempt a description of a version selector I'd
appreciate it.
<geoff>
Your "copy-based" description is just fine. A version-selector displays a
copy of the content and dead properties of a particular version (namely,
the one identified by its DAV:target property).
An additional live property (beyond DAV:target and DAV:lockdiscovery) that
will commonly have different values on a version selector and its target
version is DAV:getlastmodified.
It is common for a server to increase DAV:getlastmodified on a target
selector whenever the DAV:target is changed, while the DAV:getlastmodified
value of the target will decrease when an earlier version is made the
target.
</geoff>