Next message: Henry K. Harbury: "RE: Versioning TeleConf ... 2pm-3pm EST"
Date: Fri, 15 Sep 2000 09:35:02 -0400 (EDT)
Message-Id: <200009151335.JAA09723@tantalum.atria.com>
From: "Geoffrey M. Clemm" <geoffrey.clemm@rational.com>
To: ietf-dav-versioning@w3.org
Subject: Re: Naive question
From: Tim_Ellison@uk.ibm.com
<tim/> I also thought that the Target-Selector could be used to locally
override the Version-Selector target.
What DAV:getlastmodified do you expect to get back from PROPFIND when
you use a Target-Selector header? If you change the version selector
to refer to an older version, the difference between these is
especially critical.
For a Target-Selector header, I believe the answer should be "the one
for the version", because you want the modification date of the
version you specified.
Without a Target-Selector header, I believe the answer must be "the
one for the target selector". In particular, the modification date
for the target selector should increase on every SET-TARGET operation
on that target selector.
So a Target-Selector header should be a redirector (and causes the
request to be redirected to the specified version), but a version
selector is *not* a redirector, but rather is a resource in its own
right (which happens to have the same content and dead properties
of some other resource, namely the resource identified by the DAV:target
property of the version selector).
Similar arguments apply for MOVE, DELETE, LOCK, etc.
<tim>
If I choose to implement some live
properties to do some funky application specific thing, then I would like
to make them visible through the version selector.
</tim>
You are certainly free to do so. Just include in the definition of your
live property that "the value of this property on a version selector is
the same as the value of the target of the version selector". My point
here was just that the protocol should not define/constrain the behavior
of live properties (other than the ones explicitly defined in the protocol),
so that you *can* make them do some funky application specific thing.
There are some live properties whose value on a version selector should
mimic those on the current target, but there are others that should not,
and a particular live property needs to be able to define which behavior
it will display.
Cheers,
Geoff