XOM API for Processing XML with Java

[Nils_Kilden-Pedersen AT Countrywide.Com]

"Elliotte Rusty Harold" <elharo AT metalab.unc.edu> wrote on 11/25/2003 
07:58:17 PM:

> At 9:25 PM -0500 11/25/03, John Cowan wrote:
> 
> >I think ':' would be a better indicator: all absolute URIs have to have 
':'
> >in them, and no attribute name can.
> 
> 
> Yes, they can. xml:lang, xml:space, xlink:href, etc. Remember XOM 
> accepts qualified names as arguments. Unlike JDOM it does not take 
> the prefix and local name as separate arguments.

Also these are not necessarily "real" URIs, they are namespace URIs, which 
can really be anything.
>From elharo AT metalab.unc.edu  Sun Nov 30 21:16:53 2003
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Subject: [XOM-interest] xml: prefix and namespace in XOM
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While working on another problem today I discovered some 
inconsistencies with how XOM was handling elements and attributes in 
the http://www.w3.org/XML/1998/namespace namespace which normally 
bound to the prefix xml. The new scheme is as follows:

1. The prefix xml may only be bound to the namespace URI 
http://www.w3.org/XML/1998/namespace (This was supposed to be 
enforced previously, but it was possible to sneak around it.)

2. The namespace URI http://www.w3.org/XML/1998/namespace can only be 
bound to the prefix xml, not to other prefixes. This is new. It's not 
actually part of Namespaces 1.0, but was added in a later erratum. If 
this bothers anyone, I could see taking the constraint out.

3. Elements can now begin with the prefix xml. Previously they 
couldn't, though that was an unintentional bug. This feels flaky to 
me. On the one hand, the xml: prefix is reserved for use by the W3C, 
and they have not defined any use of xml: in element names. On the 
other hand, there's nothing to say they won't in the future. I 
noticed the problem when I was writing a filter to convert all 
non-namespace attributes to child elements, and it got tripped up by 
xml:base and xml:lang attributes.

None of these changes affect the API in any way. I'm not perfectly 
comfortable with this (probably just because the xml: prefix is one 
of the uglier parts of XML and no solution could be perfectly 
comfortable) so if anyone has an opinion or an argument about why 
doing it some other way would be better, I'm open to suggestions.


-- 

   Elliotte Rusty Harold
   elharo AT metalab.unc.edu
   Effective XML (Addison-Wesley, 2003)
   http://www.cafeconleche.org/books/effectivexml            
   
http://www.amazon.com/exec/obidos/ISBN%3D0321150406/ref%3Dnosim/cafeaulaitA