Re: Working collections

I propose that we disallow CHECKOUT of a collection version.

Tim Ellison
Java Technology Centre, MP146
IBM UK Laboratory, Hursley Park, Winchester, UK.
tel: +44 (0)1962 819872  internal: 249872  MOBx: 270452
---------------------- Forwarded by Tim Ellison/UK/IBM on 2000-11-15 11:35
AM ---------------------------

Tim Ellison
2000-11-10 10:45 AM

To:   ietf-dav-versioning@w3.org
cc:
From: Tim Ellison/UK/IBM@IBMGB
Subject:  Working collections


It seems a long time since this was last discussed -- well I've forgotten
the explanation so here goes:

We agreed that URLs to versions exist outside the normal DAV namespace.
This is concept is variously reflected in the spec as virtually hosted URLs
(http://repo.webdav.org/his/23/ver/42) and 'stolen' parts of the root
collection namespace (e.g. http://www.webdav.org/repo/wr-157.html).

Clients should not, therefore, expect to be able to construct new URLs
based on these server maintained URLs (i.e. removing / adding segments to
reach other resources).

Q1:
We know that a versioned collection is a mapping from names to version
histories.  So when you check out a versioned collection what can you do
with the resulting working collection?  Are you constrained to creating
members that bind to histories only?  Are you prevented from creating new
bindings at all?

Q2:
Can you delete bindings from a working collection -- presumably yes since
if you can't change a working collection's members you can only use them to
change properties? (There is clearly a good case for checked out collection
version selectors).

When the server sees a URL to a working collection, say of the form
http://repo.webdav.org/vr/9/wr/1/foo it can 'know' about the form of these
URLs to determine that everything up to 'foo' is the URL to the working
collection and 'foo' is the member of that collection, but there would be
(typically) no relationship between that URL and the URL of the history
resource that 'foo' is currently bound to; so it would not be possible to
slash-through 'foo' to reach other resources.

Tim

Received on Wednesday, 15 November 2000 06:45:07 UTC