> Hi,
> 
> Sorry if this has been asked before - or is a daft question.
> 
> Is it possible to parameterise an <xsl:sort> ?
> 
> Example.
> 
> 	<root>
> 		<data>
> 			<firstname value="Fred"/>
> 			<lastname value="Smith"/>
> 		</data>
> 		<data>
> 			<firstname value="Tom"/>
> 			<lastname value="Jones"/>
> 		</data>
> 		<data>
> 			<firstname value="Myles"/>
> 			<lastname value="Ward"/>
> 		</data>
> 		...
> 	</root>
> 
> Sometimes I want to sort <data> on "firstname/@value" 
> sometimes on "lastname/@value" based on a user parameter of some kind.
> 
> Is this possible?

You will need to an extension function if you want to evualate an xpath
at run time, so if you have:

 <xsl:param name="sortParam" select="'lastname/@value'"/>

Where you pass in the sort criteria as a parameter, you would need to
use:

 <xsl:sort select="saxon:evaluate($sortParam)"/>

The evaluate() extention function will turn a string into an xpath.


If your data was simple enough, or more to the point your sort criteria
was simple enough, such as a single element name:

 <xsl:param name="sortParam" select="'lastname'"/>

Then you can get away without using an extension functions, such as:

 <xsl:sort select="*[local-name() = $sortParam]/@value"/>

I think this still applies for xslt 2.0.

Cheers
andrew

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