source: rfc2629xslt/extractExtRefs.xslt

<!--
    Extract external (image) references from RFC2629 XML format

    Copyright (c) 2010, Julian Reschke (julian.reschke@greenbytes.de)
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-->

<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
               xmlns="http://www.daisy.org/z3986/2005/ncx/" 
               version="1.0"
>

<xsl:output method="text" encoding="UTF-8"/>

<xsl:template match="/">
  <xsl:for-each select="//artwork/@src">
    <xsl:choose>
      <xsl:when test="contains(.,'/')">
        <xsl:message>ERROR: referenced file <xsl:value-of select="."/> must be in the same folder as the base file.</xsl:message>
      </xsl:when>
      <xsl:when test="not(../@type)">
        <xsl:message>ERROR: referenced file <xsl:value-of select="."/> missing media type attribute.</xsl:message>
      </xsl:when>
      <xsl:otherwise>
        <xsl:value-of select="."/>
        <xsl:text>&#10;</xsl:text>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:for-each>
</xsl:template>

</xsl:transform>