Listing 2-6. Namespace Handling in XSLT and XPath
<xsl:stylesheet
xmlns:xsl=”http://www.w3.org/1999/XSL/Transform”
version=”1.0”
>
<xsl:output method=”html”/>
<xsl:template match=”/”>
<html><head><title>Two Chairmen’s Wisdom</title></head><body>
<xsl:apply-templates />
</body></html>
</xsl:template>
<xsl:template match=”*[local-name()=’saying’]”>
<xsl:variable name=”color”>
<xsl:choose>
<xsl:when test=”contains(namespace-uri(),’red’)”>red</xsl:when>
<xsl:when test=”contains(namespace-uri(),’green’)”>green</xsl:when>
<xsl:otherwise>blue</xsl:otherwise>
</xsl:choose>
</xsl:variable>
<div style=”{concat(‘color:’,$color)}”>
<xsl:apply-templates/>
</div>
</xsl:template>
</xsl:stylesheet>
The match attribute of that template matches all element nodes (that’s what
the asterisk stands for) such that their local name is saying. As you can see, XPath
has a local-name() function and (a few lines farther down) a namespace-uri()
function. Both return strings that you can work with using XPath string functions,
such as contains(). To compute the color name, we use xsl:choose (the XSLT
equivalent of the switch statement in C and derived languages).
If all namespace URIs contained the color name right after the substring
sayings.org, we could replace the xsl:choose expression with code that extracts
the color name from the namespace URI:
<xsl:variable name=”color”
select=”substring-after(namespace-uri(),’.sayings.org.’)”
>
This would generate different colors from different data without any changes
in the stylesheet.
57
Well-Formed Documents and Namespaces
