W3C home > Mailing lists > Public > w3c-dist-auth@w3.org > April to June 2001

RE: Issue: PROP_ATTR

From: Julian F. Reschke <julian.reschke@gmx.de>
Date: Wed, 11 Apr 2001 19:36:55 +0200
To: "Jim Whitehead" <ejw@cse.ucsc.edu>, "WebDAV WG" <w3c-dist-auth@w3.org>
Message-ID: <AFEIKENBELCNEGJFCENGMEEHDCAA.julian.reschke@gmx.de>
Let's try to approach it this way:

A property is a tupel of (namespacename, localname, content).

content can be (for instance) empty, a string, or mixed XML content. By
definition, it can by anything that belongs to the property element's
infoset (including anything below it).

If "content" is not a simple string, it needs to be stored in an
XML-friendly way. For instance, elements or attributes in the content might
use namespace prefixes that have been defined outside that element. For
instance:

<proppatch xmlns="DAV:" xmlns:x="foo"><set>
<prop>
<bar><x:baz/></bar>
</prop>
</set></proppatch>

If attributes of the property itself need to be recorded as well, that's
extremely easy to do: just instead of storing the "content" of the element,
you store the XML serialization of the element including it's attributes and
children.

Two other notes:

a) It needs to be specified which parts of the Infoset are preserved
(comments, processing instructions)? I'd say: all of them.

b) Microsoft's webfolders already use the old XML data namespace to put data
type information into properties, for instance <DAV:getlastmodified
dt:type="isoDate.tz" />.

Julian


> -----Original Message-----
> From: w3c-dist-auth-request@w3.org
> [mailto:w3c-dist-auth-request@w3.org]On Behalf Of Jim Whitehead
> Sent: Wednesday, April 11, 2001 7:13 PM
> To: WebDAV WG
> Subject: RE: Issue: PROP_ATTR
>
>
> > > The real question is about attr1. I see that attribute
> > > as part of the element that *names* a property, but it
> > > isn't part of the property *value*.
> >
> > That's an interesting comment -- I'd say that everything from
> the opening
> > element <theprop... to the closing element </theprop> is the
> property, and
> > the outermost element is called its 'name'.  Everything about
> the property
> > should be stored, including 'copying down' namespace declarations where
> > required.
>
> Since persisting the attributes is going to be tricky enough, my
> leaning is
> to only allow namespace and xml:lang attributes in the property name tag.
>
> However, I do agree that servers MUST persistently store XML attribute
> information found in the value of the property. I don't care how
> they store
> it -- the XML is just a marshalling format. I agree with the suggestion to
> look at the XML Canonicalization Recommendation for ideas on how
> to specify
> the round-trip behavior <http://www.w3.org/TR/xml-c14n>.
>
> It's important to support XLink style linking
> <http://www.w3.org/TR/2000/PR-xlink-20001220/>, and this is
> *very* dependent
> on the use of attributes.  Storage of XLinks in DAV properties is a very
> natural way to persistently attach link metadata to a resource --
> the major
> roadblock holding this up at present is the fact that, right now, a client
> does not have a guarantee that attribute information will be persistently
> stored.  I'm glad to see the sentiment of the working group
> leaning in this
> direction.
>
> - Jim
>
Received on Wednesday, 11 April 2001 13:37:36 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 2 June 2009 18:43:55 GMT