RE: Uniqueness of QNames in 'extends' attribute

I agree with the sentiment, but I'm not altogether happy with the phrasing. How about "The list of QNames in an extends attribute MUST NOT contain duplicates."?
 
Tony Rogers
CA, Inc
Senior Architect, Development
tony.rogers@ca.com
co-chair UDDI TC at OASIS
co-chair WS-Desc WG at W3C

________________________________

From: www-ws-desc-request@w3.org on behalf of Arthur Ryman
Sent: Fri 19-May-06 23:23
To: woden-dev@ws.apache.org
Cc: John Kaputin; woden-dev@ws.apache.org; www-ws-desc@w3.org
Subject: Re: Uniqueness of QNames in 'extends' attribute



John, 

Thx for the comment. I think that we should require uniqueness of interfaces at the XML infoset level since it makes no sense to extend from an interface twice. Therefore, a duplicate would be a programming error and raising it would be helpful to authors who may have forgotten to edit a QName after a copy and paste: 

"Each QName in the extends attribute information item MUST be unique." 

Arthur Ryman,
IBM Software Group, Rational Division

blog: http://ryman.eclipsedevelopersjournal.com/
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"John Kaputin (gmail)" <jakaputin@gmail.com> 

05/18/2006 12:39 PM 
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Uniqueness of QNames in 'extends' attribute	

		




When I implemented interface extension in Apache Woden recently I noticed that the WSDL 2.0 spec does not say that the QNames in the 'extends' attribute of the <interface> element have to be unique, although it seems sensible that they should be. Anyway, my implementation just checks for duplicate QNames before resolving them to Interface components.  

You may want to add a uniqueness constraint to this section....

2.2.2.2 <http://2.2.2.2/>  extends attribute information item 

The extends attribute information item lists the interfaces that this interface derives from. 

The extends attribute information item has the following Infoset properties: 

*	A [local name] of extends 
*	A [namespace name] which has no value

The type of the extends attribute information item is a whitespace-separated list of xs:QName. 


regards,
John Kaputin