Question

I’m passing in a bunch of key-value pairs as parameters to a XSL (date -> ’20th January’, author -> ‘Dominic Rodger’, …).

These are referenced in some XML I’m parsing – the XML looks like this:

<element datasource='date' /> 

At present, I can’t work out how to get 20th January out of these except with a horrible <xsl:choose> statement:

<xsl:template match='element'>   <xsl:choose>     <xsl:when test='@datasource = 'author''>       <xsl:value-of select='$author' />     </xsl:when>     <xsl:when test='@datasource = 'date''>       <xsl:value-of select='$date' />     </xsl:when>      ...   </xsl:choose> </xsl:template> 

I’d like to use something like:

<xsl:template match='element'>   <xsl:value-of select='${@datasource}' /> </xsl:template> 

But I suspect this isn’t possible. I’m opening to using external function calls, but want to avoid having to enumerate all possible map keys in my XSL. Any ideas?

Thanks,

Dom

Answer 1

Here is one possible solution, however I’d recommend grouping all parameters in a separate XML file and accessing them with the document() function:

<xsl:stylesheet version='1.0'  xmlns:xsl='http://www.w3.org/1999/XSL/Transform'  xmlns:ext='http://exslt.org/common'  exclude-result-prefixes='ext'  >  <xsl:output method='text'/>   <xsl:param name='date' select=''01-15-2009''/>  <xsl:param name='author' select=''Dominic Rodger''/>  <xsl:param name='place' select=''Hawaii''/>  <xsl:param name='time' select=''midnight''/>   <xsl:variable name='vrtfParams'>    <date><xsl:value-of select='$date'/></date>    <author><xsl:value-of select='$author'/></author>    <place><xsl:value-of select='$place'/></place>    <time><xsl:value-of select='$time'/></time>  </xsl:variable>   <xsl:variable name='vParams' select='ext:node-set($vrtfParams)'/>      <xsl:template match='element'>       <xsl:value-of select=        'concat('&#xA;', @datasource, ' = ',                $vParams/*[name() = current()/@datasource]                )'        />     </xsl:template> </xsl:stylesheet> 

When this transformation is applied on the following XML document:

<data>   <element datasource='date' />   <element datasource='place' /> </data> 

the correct result is produced:

date = 01-15-2009

place = Hawaii

Do note the use of the xxx:node-set() function (the EXSLT one is used here) to convert an RTF (Result Tree Fragment) to a regular xml document (temporary tree).