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Re: Boeing XRI Use Cases

From: John Bradley <john.bradley@wingaa.com>
Date: Tue, 15 Jul 2008 08:20:02 -0700
Cc: Mark Baker <distobj@acm.org>, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, "www-tag@w3.org" <www-tag@w3.org>
Message-Id: <99D30020-5C2B-4220-9EEB-4E0D5ECF777E@wingaa.com>
To: Julian Reschke <julian.reschke@gmx.de>

On 15-Jul-08, at 2:24 AM, Julian Reschke wrote:

> John Bradley wrote:
>> ...
>> If there is a document stating how others like webdav were able to  
>> navigate this process, perhaps that could be of some help to the  
>> XRI-TC.
>> ...
> WebDAV extends HTTP, and addresses resources through regular HTTP(s)  
> URIs.
> The "DAV:" URI scheme was only defined for use as an XML namespace  
> name, which was certainly an extremely bad idea in the first place.  
> RFC 4918, which obsoletes RFC 2518, continues to do so only for  
> backwards compatibility (see <http://www.webdav.org/specs/rfc4918.html#rfc.section.21.1 
> >). (That Subversion re-did that mistake with it's (non-registered)  
> "svn:" scheme doesn't help.)
> BR, Julian

Thanks for the information Julian,

I don't think it has ever been a goal to use xri: as a XML namespace  

Yes we would be guilty as charged if you look at a XRDS or at places  
in the XRI 2.0 spec where this occurs.

It's a bit of a pride thing,  we defined a URI form of an XRI so we  
used it in our own definitions.

It is my belief that there is no place in the spec where xri: is used  
as a XML namespace name that a URL could not have been used.

  <XRD version="2.0" xmlns="xri://$xrd*($v*2.0)">

This uses the XRI versioning syntax that we have some attachment to.

David Orchard has concerns that this is not a valid URI.

That is one question I don't think has been resolved completely.
If the scheme were registered is this valid as a URI without further  

In my email to David I review the transformations required to go from  
XRI-Normal form to URI-Normal form.

If to make people happy we use the HXRI form it is not the end of the  
world.  It will take 1 month of writing and 6 months of OASIS process  
to get a revised spec to a vote.

The XRI-TC believes that it has done the correct thing with the URI- 
Normal form.  To my knowledge no specific technical fault has been  
found with it.

Yet I at least (the XRI-TC will tell you I don't speak for all of  
them) am willing to consider abandoning the use of the URI-Normal form.
Using http scheme URLS exclusively in XML namespaces is just fine with  

My question around WEBDAV was not really directed at XML but rather  
the processing by WEBDAV aware clients of webdav URLs in the http:  

WEBDAV extended the operators beyond GET and POST,  and had a extended  
web server that dealt with information encoded in the path.

We have not proposed new operators to extend the http protocol with  

If xri and webdav and http are to all share the same http: scheme  
addressing then how are the clients like XDI servers and possibly web  
browsers going to recognize these URIs?

Is there something we can learn from others attempts to fit themselves  
into the http: scheme?

Some people feel that if we conform to http: scheme addressing we must  
still justify XRI in some way.

How have other people met this challenge?

I ask about WEBDAV because it would appear to have some of the same  
issues we will encounter tying to re-use the http: scheme.

I will have a look at RFC 2518 to see if it can shine some light on  

Thank you for your input.

John Bradley

Received on Tuesday, 15 July 2008 15:20:46 UTC

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