Subject: Issue: PROP_ATTR

From: "Jim Whitehead" <[email-masked]>
Date: Tue, 10 Apr 2001 17:53:30 -0700

As mentioned in a previous post, now is the time to start resolving issues
on the RFC 2518 issues list.  As fate would have it, the first issue on the
list is one that has been contentious in the past. Can we come to consensus
on it now?

Issue: PROP_ATTR

Description:

What is a WebDAV server required to do with XML attributes other than
xml:lang submitted with a PROPPATCH?  This affects how well WebDAV will be
able to support RDF, since RDF uses attributes extensively.

Greg Stein originally raised this issue:

http://lists.w3.org/Archives/Public/w3c-dist-auth/1998OctDec/0089.html

See also:

http://lists.w3.org/Archives/Public/w3c-dist-auth/1998OctDec/0092.html
http://lists.w3.org/Archives/Public/w3c-dist-auth/1998OctDec/0094.html
http://lists.w3.org/Archives/Public/w3c-dist-auth/1998OctDec/0095.html

---

From: "Mark A. Hale" <[email-masked]>
Date: Tue, 10 Apr 2001 18:29:00 -0700

Jim:  Thanks for getting the issues list started.

I believe that WebDAV must permit properties to have attributes.  As you've
pointed out, RDF and PRISM do use them extensively.  A server can reformat
the attributes in a subsequent PROPFIND request.  Attrbiutes should be
persistent.

	Thanks,

	Mark

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of Jim Whitehead
> Sent: Tuesday, April 10, 2001 5:54 PM
> To: WebDAV WG
> Subject: Issue: PROP_ATTR
>
>

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From: "Eric Sedlar" <[email-masked]>
Date: Tue, 10 Apr 2001 22:58:21 -0700

I agree.  There is no reason not to persist attributes.

> [mailto:[email-masked]]On Behalf Of Mark A. Hale
> Sent: Tuesday, April 10, 2001 6:29 PM
> To: WebDAV WG
> Subject: RE: Issue: PROP_ATTR
>
>

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From: "Julian F. Reschke" <[email-masked]>
Date: Wed, 11 Apr 2001 09:45:33 +0200

I agree here.

Maybe the way property values are round-tripped needs to be defined in terms
of the XML infoset [1] or the Canonical XML rec [2].

If a server supports "arbitrary" content of properties (like child elements
with attribute, mixed content and so on), it will have to store the content
in some XML friendly format anyway. Instead of storing the "value" of the
property (all contained elements?), it can instead store the element (with
all it's attributes and childs), thus preserving all attribute information.

[1] <http://www.w3.org/TR/xml-infoset/>
[2] <http://www.w3.org/TR/xml-c14n>

> Sent: Wednesday, April 11, 2001 3:29 AM
> To: WebDAV WG

---

From: Greg Stein <[email-masked]>
Date: Wed, 11 Apr 2001 01:06:29 -0700

The question isn't about attributes in general, it is about *which*
attributes. Consider the following:

  <D:prop>
    <theprop attr1="foo">
      thevalue
      <subelem attr2="bar"/>
    </myprop>
  </D:prop>

I believe everybody would agree that attr2 gets stored. 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*.

IMO, PROP_ATTR is about defining the boundary between property naming, and a
property's value.

Cheers,
-g

-- 
Greg Stein, http://www.lyra.org/

---

From: "Kevin Wiggen" <[email-masked]>
Date: Fri, 13 Apr 2001 09:02:25 -0700

I agree with Greg et all that "attr2" needs to be stored.

I believe that allowing "attr1" could lead to some interop problems, or we
need to spec this out a little better:

<D:prop>
  <theprop attr1="foo"/>
  <theprop attr1="bar"/>
  <theprop attr2="fee"/>
</D:prop>

Is that legal?  Does the attribute make the property unique?  Does simply
the value of an attribute make it unique?  Or do we (like xmllang) simply
store one set of attributes for a property?

Also how does one use Dasl with attributes on properties?

I would like to see attributes on the property name not be supported.

Kevin

-----Original Message-----
From: [email-masked]
[mailto:[email-masked]]On Behalf Of Greg Stein
Sent: Wednesday, April 11, 2001 1:06 AM
To: WebDAV WG
Subject: Re: Issue: PROP_ATTR

  <D:prop>
    <theprop attr1="foo">
      thevalue
      <subelem attr2="bar"/>
    </myprop>
  </D:prop>

Cheers,
-g

---

From: "Julian F. Reschke" <[email-masked]>
Date: Sat, 14 Apr 2001 12:23:54 +0200

> [mailto:[email-masked]]On Behalf Of Kevin Wiggen
> Sent: Friday, April 13, 2001 6:02 PM
> To: Greg Stein; WebDAV WG

No, it doesn't. If the language in section 4.5
(<http://www.greenbytes.de/tech/webdav/rfc2518.html#rfc.section.4.5>) isn't
clear enough on that, it should be enhanced.

> store one set of attributes for a property?

Who does? RFC2518 says that xml:lang must be preserved, but it doesn't say
that there may be multiple copies of the property with different language
values (<http://www.greenbytes.de/tech/webdav/rfc2518.html#ELEMENT_set>).

> I would like to see attributes on the property name not be supported.

I might agree, but not for the reasons given here.