Re: [xml] XSLT question, regarding RSS

[Adam Trachtenberg <adam trachtenberg com>]

On Apr 29, 2004, at 3:41 AM, Fabrice Desré FTR&D/DTL/TAL wrote:

>  Well, this is not an XSLT oddity, this is because XPath has no 
> concept of a default namespace. For XPath, no prefix means no 
> namespace, and not the default namespace of the stylesheet. What it 
> means is that you have to declare a prefix for each and every 
> namespace used in an XPath expression, even if the elements you want 
> to select appear to be scoped by the default ns in the xml data.

I know the distinction between the two, and the solution. What I was 
trying to say is that while this distinction may be clear to XPath 
experts, it is not to XPath novices. The distinction is too subtle and 
it's confusing to many first time XSLT users.

See Section 2.0 and 2.1 from the XSLT 2.0 Requirements Working Draft  
(http://www.w3.org/TR/xslt20req):

> 2
> Must Improve Ease of Use
>
> XSLT 2.0 MUST address frequently requested enhancements to make  using 
> XPath even more straightfoward for handling common use  cases.
>         
> 2.1
> Must Allow Matching on Default Namespace  Without Explicit Prefix
>
> Many users stumble trying to match an element with a default  
> namespace. They expect to be able to do something like:
>         <xsl:stylesheet version="1.0"
>                  xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
>                  xmlns="urn:myuri">
>
>           <!-- Expect this matches <foo> in default namespace
>         -->
>
>           <xsl:template match="foo">
>
> thinking that leaving off the prefix from the foo  element name, that 
> it will match <foo> elements in  the default namespace with the URI of 
> urn:myuri. Instead,  they are required to assign a non-null prefix 
> name to their namespace  URI and then match on "someprefix:foo" 
> instead, which has  proven to be far from obvious. XSLT 2.0 SHOULD 
> provide an explicit way  to handle this scenario to avoid further user 
> confusion.

I think "proven to be far from obvious" is pretty much standards-speak 
for "oops, maybe that wasn't a good design decision after all." :)

-adam

--
adam trachtenberg
adam trachtenberg com