How to do dynamic xquery?

[David]

I find we can dynamically create XPath expressions and use them for the XPath command <xpath expression="${my_xpath}">...
I have not been able to generate a dynamic query in XQuery. Example:

<var-def name="my_xpath">//td[3]/h2[1]</var-def>
<xquery>
<xq-param name="item"><var name="item"/></xq-param>
<xq-param name="my_xpath"><var name="my_xpath"/></xq-param>
<xq-expression><![CDATA
let $name := data($item{$my_xpath})
return
<product>
<name>{normalize-space($name)}</name>
</product>
]></xq-expression>
</xquery>

This code produces an exception. Is there a way to make this work?

[Vladimir Nikic]

try to surround xquery expression with <template>:

<xq-expression>
<template>
<![CDATA
let $name := data($item${my_xpath}) return
<product>
<name>{normalize-space($name)}</name>
</product>
]>
</template>
</xq-expression>

so that templating processor will first replace your xpath with variable.

[David]

makes perfect sense. thanks a million