<?xml version="1.0"?>
<xsl:stylesheet version="1.0" 
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
   xmlns:php="http://php.net/xsl"
   xmlns:fn="http://exslt.org/functions"
   xmlns:event="http://www.www.com"
   extension-element-prefixes="php fn event">  
   
   <xsl:template name="trigger-event">
    <xsl:value-of 
         select="php:function('EventManager::Trigger', .)" 
         disable-output-escaping="yes" />
   </xsl:template>
   
  <fn:function name="event:trigger">
    <xsl:param name="eventName"/>
    <fn:result>
      <xsl:value-of 
        select="php:function('EventManager::Trigger',$eventName)"/>
    </fn:result>
  </fn:function>
  
</xsl:stylesheet>