RE: [xsl] Recursive evaluation of expressions

["Michael Kay" <mike@xxxxxxxxxxxx>]

You're asking it to output the result of concat($p1/../caption, ' ',
$p1/description), and that's what it's doing. If you want to treat
caption/eval as an expression and evaluate it, rather than outputting its
string value, then you will have to ask for that by another call on
saxon:evaluate().

Regards,

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

> -----Original Message-----
> From: Rowan Sylvester-Bradley [mailto:rowan@xxxxxxxxxxxxxxxxxxxxx] 
> Sent: 19 December 2009 01:18
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] Recursive evaluation of expressions
> 
> I'm still struggling to get this working. I need to be able 
> to evaluate XPath expressions in my input XML document. This 
> works OK, but I also need to be able to refer in an XPath 
> expression to an element that contains another expression, 
> and to pick up the result of evaluating the second 
> expression, not just the text of the expression.
> Here's a sample input document:
> <items>
>    <item>
>       <id>a</id>
>       <caption>Sandwich Meal</caption>
>       <item>
>          <id>a1</id>
>          <description>White roll</description>
>          <caption><eval>concat($p1/../caption, ' ', 
> $p1/description)</eval></caption>
>          <item>
>             <id>a1a</id>
>             <description>Chicken</description>
>             <caption><eval>concat($p1/../caption, ' ', 
> $p1/description)</eval></caption>
>          </item>
>          <item>
>             <id>a1b</id>
>             <description>Ham</description>
>             <caption><eval>concat($p1/../caption, ' ', 
> $p1/description)</eval></caption>
>          </item>
>       </item> 
>    </item>    
> </items>                 
> 
> And here's a simplified version of my stylesheet:
> <xsl:stylesheet version="2.0" 
>    xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
>    xmlns:xs="http://www.w3.org/2001/XMLSchema";
>    xmlns:saxon="http://saxon.sf.net/";
>    exclude-result-prefixes="xs saxon">
> 
>    <xsl:strip-space elements="*"/>
>    <xsl:output indent="yes"/>
>    
>    <xsl:template match="node()|@*">
>       <xsl:copy>
>          <xsl:apply-templates select="node()|@*"/>
>       </xsl:copy>
>    </xsl:template>  
>    
>    <xsl:template match="item">
>       <item>
>          <xsl:apply-templates>
>             <xsl:with-param name="source" select="." tunnel="yes"/>
>          </xsl:apply-templates>   
>       </item>
>    </xsl:template>
>    
>    <xsl:template match="eval">
>       <xsl:param name="source" tunnel="yes"/>
>       <xsl:value-of select="saxon:eval(saxon:expression(.), 
> $source)"/>
>    </xsl:template>   
> 
> </xsl:stylesheet>  
> 
> This produces the following:
> <?xml version="1.0" encoding="UTF-8"?>
> <items>
>    <item>
>       <id>a</id>
>       <caption>Sandwich Meal</caption>
>       <item>
>          <id>a1</id>
>          <description>White roll</description>
>          <caption>Sandwich Meal White roll</caption>
>          <item>
>             <id>a1a</id>
>             <description>Chicken</description>
>             <caption>concat($p1/../caption, ' ', 
> $p1/description) Chicken</caption>
>          </item>
>          <item>
>             <id>a1b</id>
>             <description>Ham</description>
>             <caption>concat($p1/../caption, ' ', 
> $p1/description) Ham</caption>
>          </item>
>       </item>
>    </item>
> </items>
> 
> What I want instead of              
>             <caption>concat($p1/../caption, ' ', 
> $p1/description) Chicken</caption> is
>             <caption>Sandwich Meal White roll Chicken</caption>
> 
> How can I get it to do this?
> 
> Many thanks - Rowan