- From: Greg Stein <gstein@lyra.org>
- Date: Thu, 1 Feb 2001 03:08:58 -0800
- To: ietf-dav-versioning@w3.org
I've been thinking a bit about PROPFIND and the Label: header. Let's say that I do a PROPFIND against a VCR using a Label header: PROPFIND /some/vcr Label: foo response... <D:multistatus ...> <D:response> <D:href>/the/version/resource</D:href> ... The DAV:href element presumably has the version resource URI because you did a PROPFIND against that resource (effectively). Now, let's throw the Depth: header into the mix. What does it apply to? The VCR or the Version? It is murky with the Label: header in there. Depth applies to the VCR: The PROPFIND will return DAV:response elements for version resources corresponding to those selected by the label, from each of the VCRs according to the Depth. DAV:href returns Version Resource URIs. How do we match them up against the hierarchy defined by the VCRs? Depth applies to the Version Resource: Presumably, you're selecting a collection version. Its children are version histories, so you're going to get back whacky properties or nothing at all for the children. The DAV:href probably would exist here, too: which DAV:response is for the collection version, and which for the members? [ you could tell by looking for errors :-) ] Okay... let's try to fix the DAV:href thingy by saying you apply the Depth: header to the VCRs (i.e. apply Depth to the VCR before linking thru to the version resources) and the DAV:href returns the VCRs' URIs. That makes some sense, but now we have a problem: how do we get the version resource URI? We can't use DAV:checked-in because that is a VCR prop. And, oh darn! We just nuked DAV:version. My suggestion: *) define Depth: on a PROPFIND of a VCR to apply to the VCR hierarchy rather than the version resource (lack of) hierarchy *) the DAV:href returns the VCR's URI [ I'm not sure that I like this, though :-( ] *) bring back DAV:version Hmm. I'm thinking that the use of a Label: header is rather spurious to the above issue. It does make it a bit harder to figure out the version resource URI (without the Label:, you could ask for the VCR's DAV:checked-in; there isn't an easy equivalent to find the V.R. when you're trying to use a label) Cheers, -g -- Greg Stein, http://www.lyra.org/
Received on Thursday, 1 February 2001 06:08:23 UTC