Hi David,

thanks very much for the thorough working example. I see what you have 
done. I guess if I wanted a generic way to provide this functionality 
I'd have to write a third pass stylesheet. I.e. if I have no way of 
knowing which nested elements are references of not.

FYI, I'm actually transforming a serialised graph of Java objects. This 
means that elements which use references and elements which don't can 
change quite easily when java code is refactored. So a generic, reusable 
solution would be more pleasing.

I think it also shows that I'll be much better off using an extension. I 
believe Xalan (which I am using) has such an evaluate function.

I appreciate knowing how it can be done nonetheless.

Thanks again,
Pat.

David Carlisle wrote:

> Pat Turner <purpletrousers@n...> writes:
> 
> 
>>Thanks David,
>>
>>errrm, could you give me an example of what the first pass stylesheet 
>>would look like using my example? I can't think how it would be done.
>>
>>TIA
>>Pat
> 
> 
> several ways, depending how generic/efficient you want to be.
> 
> for example
> 
> input doc (eval.xml):
> 
> <family>
> 	<person name="bob">
> 		<father ref="../../person[2]" />
> 	</person>
> 	<person name="charlie">
> 		<child ref="../../person[1]" />
> 	</person>
> </family>
> 
> 
> proto-stylesheet (eval1.xsl)
> 
> 
> <xsl:stylesheet	version="1.0"
> xmlns:x="data:,x"
> xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
> 
> 
> <xsl:template mode="a" match="person">
>   <xsl:value-of select="@name"/>
> </xsl:template>
> 
> <xsl:template match="person">
> Person:  <xsl:value-of select="@name"/>
>          <xsl:apply-templates select="father|child"/>
> </xsl:template>
> 
> <xsl:template x:match="father">
> Father: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" x:select="@ref"/>
> </xsl:template>
> 
> <xsl:template x:match="child">
> Child: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" x:select="@ref"/>
> </xsl:template>
> 
> </xsl:stylesheet>
> 
> 
> in the above the syntax (which I just made up) is that templates
> depending on a generated xpath use x:match in their match pattern, and
> use x:select where they want the xpath to appear. This could be made
> more efficient (i generate all templates for all dynamic xpaths which is
> less code for me to write but generates more templates than needed)
> 
> 
> 
> Evaluation stylesheet (this has original source doc filename hardcoded,
> it could be a parameter)
> 
> <xsl:stylesheet	version="1.0"
> xmlns:x="data:,x"
> xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
> 
> 
> <xsl:template mode="a" match="person">
>   <xsl:value-of select="@name"/>
> </xsl:template>
> 
> <xsl:template match="person">
> Person:  <xsl:value-of select="@name"/>
>          <xsl:apply-templates select="father|child"/>
> </xsl:template>
> 
> <xsl:template x:match="father">
> Father: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" x:select="@ref"/>
> </xsl:template>
> 
> <xsl:template x:match="child">
> Child: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" x:select="@ref"/>
> </xsl:template>
> 
> </xsl:stylesheet>
> 
> 
> 
> 
> 
> 
> 
> generate real stylesheet
> saxon -o eval2.xsl eval1.xsl eval.xsl
> 
> eval2.xsl has several templates expanded out. and looks like
> 
> <?xml version="1.0" encoding="utf-8"?><xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:x="data:,x" version="1.0">
> 
> 
> <xsl:template mode="a" match="person">
>   <xsl:value-of select="@name"/>
> </xsl:template>
> 
> <xsl:template match="person">
> Person:  <xsl:value-of select="@name"/>
>          <xsl:apply-templates select="father|child"/>
> </xsl:template>
> 
> 
> <xsl:template match="father[@ref='../../person[2]']">
> Father: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" select="../../person[2]"/>
> </xsl:template>
> <xsl:template match="father[@ref='../../person[1]']">
> Father: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" select="../../person[1]"/>
> </xsl:template>
> 
> 
> <xsl:template match="child[@ref='../../person[2]']">
> Child: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" select="../../person[2]"/>
> </xsl:template>
> <xsl:template match="child[@ref='../../person[1]']">
> Child: <xsl:value-of select="@name"/>
>          <xsl:apply-templates mode="a" select="../../person[1]"/>
> </xsl:template>
> 
> </xsl:stylesheet>
> 
> 
> 
> run this stylesheet on original source:
> 
> $ saxon eval.xml eval2.xsl
> <?xml version="1.0" encoding="utf-8"?>
> 
> Person:  bob
> Father: charlie
> 
> Person:  charlie
> Child: bob
> 
> 
> 
> 
>