W3C home > Mailing lists > Public > w3c-dist-auth@w3.org > July to September 2003

RE: multiple "source" properties documents

From: Geoffrey M Clemm <geoffrey.clemm@us.ibm.com>
Date: Fri, 19 Sep 2003 12:35:30 -0400
To: "'WebDAV List (E-mail)'" <w3c-dist-auth@w3.org>
Message-ID: <OF47E54395.BE099420-ON85256DA6.00587FD0-85256DA6.005B248B@us.ibm.com>
I don't think the format needs to be changed, but it certainly
would need to be more clearly described.  I am continually
amazed at how such an otherwise sensible group of authors could have
chosen a node named DAV:tgt to hold the URI of the source,
and a node named DAV:src to hold the URI of what is usually the
resource itself.  Didn't they at list flinch or grimace at
the sentences:

"The destination of the source link identifies the ... source
 of the link’s source."

and

"The source of the link is typically the URI of the resource
 on which the link is defined."

One could make a good argument that this poor naming choice alone
merits deprecating the feature :-).

But back to your actual question, if there are multiple outputs
of the processing step (i.e. it produces not only the resource
identified by the request-URI, but several other resources),
then it is useful to have the DAV:src nodes to indicate what 
those other output resources are.

Cheers,
Geoff

Julian wrote on 09/19/2003 09:18:29 AM:

> Geoff,
> 
> please re-read the old discussion on the mailing list. RFC2518 
> specifies a format that indeed doesn't make any sense (can you 
> explain what the DAV:src sub-element is for?).
> 
> So *if* this feature is to remain in RFC2518, at least the format 
> needs to be fixed (possibly in a way backwards compatible to RFC2518).
> 
> Julian
> --
> <green/>bytes GmbH -- http://www.greenbytes.de -- tel:+492512807760 
> -----Original Message-----
> From: w3c-dist-auth-request@w3.org [mailto:w3c-dist-auth-request@w3.org]
> On Behalf Of Geoffrey M Clemm
> Sent: Friday, September 19, 2003 3:06 PM
> To: 'WebDAV List (E-mail)'
> Subject: RE: multiple "source" properties documents

> 
> My perspective is a bit different.  The DAV:source property 
> was designed for exactly the situation that Conal describes. 
> He'd like a generic application to pop up the list of URL's 
> and say "these are the sources".  There are no significant 
> testing issues ... the format of the DAV:source property is 
> well defined, and all a client is expected to do is to expose 
> the specified list of URL's. 
> 
> So in Conal's case, I'd just expose this feature using the 
> DAV:source property, and you are no worse off that if you 
> just defined your own custom property, and that if enough 
> folks do so, the property will become "undeprecated". 
> 
> Note: I am not arguing against deprecating the DAV:source 
> feature ... I don't think the topic is significant enough 
> to merit being re-opened ... I'm just saying that if you are 
> an implementor and encounter a valid use for the DAV:source 
> property, you should go ahead and use it instead of inventing 
> your own custom property, even if it is deprecated in 2518bis. 
> 
> Cheers, 
> Geoff 
> 
> 
> Lisa wrote on 09/18/2003 07:41:56 PM:
> 
> > 
> > 
> > > From what I read, the "source" property was a great idea but 
> > > no-one ever implemented it, supposedly because it was too 
> > > complicated and/or there was no perceived need. 
> > 
> > I'd characterize the reasons a little differently: 
> >  1) The feature was underspecified, there was never enough 
> >    information in the spec to be able to fully implement
> >    or interoperate
> >  2) Implementation interest was low -- we asked around to see
> >    who had implemented this feature and got no positive
> >    responses at all.
> > 
> > > Eventually it 
> > > was formally deprecated. Is this correct? 
> > 
> > The deprecation isn't final yet, but we are proposing to 
> > deprecate it.
> > 
> > > I've also read of 
> > > the "translate" header, which I gather is a 
> > > Microsoft-specific extension? I also gather that this only 
> > > supports a one-to-one mapping between a document and its 
> > > source, i.e. a document has one and only one source?
> > 
> > Yes
> > 
> > > My case is that I have a server which generates pages from 
> > > multiple sources and keeps track of those sources in such a 
> > > way that it could fairly easily support dav:source. I'd like 
> > > editors to be able to edit the page and select which of the 
> > > source documents to edit. But are there existing clients that 
> > > will actually do that? Or are there other web-dav mechanisms 
> > > that might support my use-case?
> > 
> > Not that I know of.  You'd be the first to implement a 
> > protocol feature to expose multiple mappings so nobody
> > to interoperate with and no tools to support your feature.
> > 
> > If there is sufficient interest from implementors to make
> > forward progress on this, I'd recommend a separate draft rather
> > than resurrect the unimplemented, underspecified, and untested
> > feature in RFC2518.
> > 
> > Lisa
> > 
> > 
Received on Friday, 19 September 2003 12:35:48 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 2 June 2009 18:44:04 GMT