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RE: Label header vs PROPFIND depth 1

From: Julian Reschke <julian.reschke@greenbytes.de>
Date: Mon, 22 Apr 2002 17:24:58 +0200
To: "Tim Ellison" <Tim_Ellison@uk.ibm.com>, "Deltav WG" <ietf-dav-versioning@w3.org>
Message-ID: <JIEGINCHMLABHJBIGKBCEEDNEHAA.julian.reschke@greenbytes.de>
> From: ietf-dav-versioning-request@w3.org
> [mailto:ietf-dav-versioning-request@w3.org]On Behalf Of Tim Ellison
> Sent: Monday, April 22, 2002 5:16 PM
> To: Deltav WG
> Subject: RE: Label header vs PROPFIND depth 1
>
>
>
> > The semantics of the depth header is explicitly defined for PROPFIND. So
> you
> > can think of it as a parameter to PROPFIND. Headers that select variants
> > simply are different.
>
> The label: header causes the method to be applied to the version -- a
> version is not a variant of a version-controlled resource, that is, a
> version is not another representation of the version-controlled resource,
> it is a whole new resource.

In absence of the LABEL header feature I would agree.

However, the label header exactly does what HTTP 1.1 defines a selecting a
variant. So if you use it to get a version rather than a VCR, you *make* the
version a variant of the VCR (like it or not).

> > > "the multistatus XML element for a collection resource with
> member URIs
> > > MUST include a response XML element for each member URI of the
> collection,
> > > to whatever depth was requested"
> > >
> > > If the label: applied to each member of the version-controlled
> collection,
> > > then the results would be a set of versions that were not related by
> > > membership.
> >
> > No, the result isn't a set of versions anyway. It is a set of *variants*
> of
> > the member VCRs. You will not see the version URIs in the response body.
>
> What do you mean by the _variants_ of a version-controlled resource?  My
> understanding is that a variant is an alternate representation of a
> resource, and that is not the case here.

Yes, it is.

The label header is a variant selector as defined per RFC2616. If this
wouldn't be the case, including "label" in the "vary" header would be wrong.
Received on Monday, 22 April 2002 11:25:53 GMT

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