Another question about generating XSLT with XSLT

danblick · July 9th, 2009, 09:52 PM

I understand how to use xsl:namespace-alias to generate XSLT documents as the result of XSLT transforms.

However, I'm still having trouble writing a stylesheet that will output a second stylesheet containing namespace-aware strings. An example will help:

Suppose I have an input document,

<stylesheet-descriptor>
<namespace>http://www.example.com</namespace>
<element-name>foo</element-name>
</stylesheet-descriptor>

How do I build a stylesheet that will take this input document and output an XSLT stylesheet that contains portions like:

<xsl:template match="e:foo" xmlns:e="http://www.example.com">

or like

<output-element output-attribute="{e:foo}" xmlns:e="http://www.example.com" />

?

Thanks very much,
Dan

iceandrews · July 16th, 2009, 04:16 PM

This is quick and dirty and definiately not the best possible solution, but it may lead down the right path. You should note that this solution only works for XSLT 2.0. It's written for the exact input document you've provided.

Code:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
 
    <xsl:template match="/">
        <xsl:apply-templates select="stylesheet-descriptor"/>
    </xsl:template>
 
    <xsl:template match="stylesheet-descriptor">
        <xsl:variable name="Prefix" select="'e'" />
        <xsl:variable name="Namespace" select="string(namespace)" /> 
        <xsl:element name="xsl:template" namespace="http://www.w3.org/1999/XSL/Transform">
            <xsl:attribute name="match" select="concat($Prefix,':',element-name)"/>
            <xsl:namespace name="{$Prefix}" select="$Namespace" />
        </xsl:element>
    </xsl:template>
 
</xsl:stylesheet>

danblick · July 16th, 2009, 08:40 PM

Thanks iceandrews. After looking into this a bit more, I concluded:

1) it's not possible to do what I originally wanted with XSLT versions < 2.0.

2) With XSLT, the xsl:namespace element works well.

Supposing that stylesheet-descriptor is in the xmlns "http://www.example.com/ns/1"; that is, something like:

<?xml version="1.0"?>
<stylesheet-descriptor xmlns="http://www.example.com/ns/1">
<namespace>http://www.example.com</namespace>
<element-name>foo</element-name>
</stylesheet-descriptor>

This stylesheet (note version 2.0):

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:example="http://www.example.com/ns/1" xmlns:axsl="http://www.w3.org/1999/XSL/TransformAlias" version="2.0" exclude-result-prefixes="example">
<xsl:namespace-alias stylesheet-prefix="axsl" result-prefix="xsl"/>
<xsl:output method="xml" indent="yes"/>
<xsl:template match="/">
<xsl:apply-templates select="example:stylesheet-descriptor"/>
</xsl:template>
<xsl:template match="example:stylesheet-descriptor">
<axsl:stylesheet version="1.0">
<axsl:output method="xml" doctype-public="-//W3C//DTD XHTML 1.1//EN" doctype-system="http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd" indent="yes"/>
<axsl:template match="/">

<foo xmlns="http://www.example.com/other-ns/1">
<axsl:apply-templates select="input:{example:element-name}">
<xsl:namespace name="input" select="example:namespace"/>
</axsl:apply-templates>
</foo>
</axsl:template>
<axsl:template match="input:{example:element-name}">
<xsl:namespace name="input" select="example:namespace"/>
<bar xmlns="http://www.example.com/other-ns/1"/>

</axsl:template>
</axsl:stylesheet>
</xsl:template>
</xsl:stylesheet>

produces the right output:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="xml" doctype-public="-//W3C//DTD XHTML 1.1//EN"
doctype-system="http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"
indent="yes"/>
<xsl:template match="/">
<foo xmlns="http://www.example.com/other-ns/1">
<xsl:apply-templates xmlns:input="http://www.example.com" select="input:foo"/>
</foo>
</xsl:template>
<xsl:template xmlns:input="http://www.example.com" match="input:foo">
<bar xmlns="http://www.example.com/other-ns/1"/>
</xsl:template>
</xsl:stylesheet>