Re: [xsl] local-name of attribute values

[Trevor Nash <tcn at melvaig dot co dot uk>]

Hi Oliver,

>
>I have an attribute base="ns:type" and want to get the local name of 
>the value, i.e. "type" in this case. Obviously this is the substring 
>after ':'. If there is base="type" then it is the whole string.
>
>A single XPath expression for this could be
>
>concat(substring(substring-after(@base,':'), 
>                 1 div contains(@base,':')),
>       substring(@base, 
>                 1 div not(contains(@base,':'))))
>
>(see http://www.dpawson.co.uk/xsl/sect2/N6461.html#d58e628 for an
>explanation)
>
>Does anybody know a shorter XPath 1.0 solution?
>(I need this as an expression for xsl:key)
>
I guess you want speed as much as brevity: if you are using a Java
processor (such as Saxon) you could try:

<xsl:key xmlns:str="java:java.lang.String" ...
      substring(@base, str:indexOf(str:new(@base), ':')+2)

The 2 works because Java counts string indexes from zero and indexOf
returns -1 if the character isn't there.  I tried it on Saxon (though
not in a key statement).  Without checking the standard I am not sure
':' is guaranteed to be interpreted as a char argument on other
processors.

You could of course do the substring() in Java too, but I'm not sure
how much benefit you would get from that.  Or write the whole
expression in Java ;-)

I would be interested in the results of any performance comparison if
you try this method.

Regards,
Trevor Nash
--
Traditional training & distance learning,
Consultancy by email

Melvaig Software Engineering Limited
voice:     +44 (0) 1445 771 271 
email:     tcn@melvaig.co.uk

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list