RE: [xsl] new: how to change value of attributes

["Michael Kay" <mike@xxxxxxxxxxxx>]

>    <xsl:template match="mets:div/@LABEL[matches(., '^Pagina [0-9]+$')]">
>      <xsl:variable name="n">
>        <xsl:number level="any" count="mets:div[@LABEL[matches(., '^Pagina
[0-9]+$')]]"/>
>      </xsl:variable>
>      <xsl:attribute name="LABEL" select="concat('Carta ', 
             if ($n mod 2 = 0) then concat(($n + 1) idiv 2, 'v') else
concat(($n + 1) idiv 2, 'r'))"/>
>    </xsl:template>
>

The redundancy of repeating the whole pattern is pretty horrible, both for
performance and for maintenance.

An idiom I have used in such cases is:

<xsl:variable name="g" select="//mets:div[matches(@LABEL, '^Pagina
[0-9]+$')]"/>

<xsl:template match="*[. intersect $g]/@LABEL">
  <xsl:variable name="n" select="f:index-of-node($g, .)"/>

where

<xsl:function name="f:index-of-node" as="xs:integer*">
  <xsl:param name="nodes" as="node()*"/>
  <xsl:param name="node" as="node()"/>
  <xsl:for-each select="$nodes">
    <xsl:sequence select="position()[current() is $node]"/>
  </xsl:for-each>
</xsl:function>

which still isn't ideal, but it feels a bit better.


Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay