XSLT, 2nd Edition

JRuby

JRuby is an implementation of the popular Ruby language written in Java. We define the namespace prefix jruby-extension and associate it with the URI http://jruby.codehaus.org. Here’s the JRuby code:

<?xml version="1.0"?>
<!-- piechart-jruby.xsl -->
<xsl:stylesheet version="1.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:svg="http://www.w3.org/2000/svg"
  xmlns:months="http://www.oreilly.com/xslt/months"
  xmlns:lxslt="http://xml.apache.org/xslt"
  xmlns:jruby-extension="http://jruby.codehaus.org"
  extension-element-prefixes="jruby-extension"
  exclude-result-prefixes="lxslt">
...
  <lxslt:component prefix="jruby-extension" 
    functions="cos sin">
    <lxslt:script lang="ruby">
      def cos(d)
        Math::cos(d)
      end

      def sin(d)
        Math::sin(d)
      end
    </lxslt:script>
  </lxslt:component>

To use these extension functions, your CLASSPATH must contain jruby.jar, available at http://jruby.codehaus.org, in addition to bsf.jar and commons-logging-1.1.jar.

Tip

The magic lang attribute value here is ruby. Using JRuby, jruby, or Ruby, all of which are reasonable choices, causes a runtime error.