<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:import href="cdcatalog.xsl2.xsl" />
  <xsl:variable name="xsl-url" select="xsl-url" />
  <xsl:template match="/">
    <xsl:choose>
      <xsl:when test="/xsl-url">
        <xsl:for-each select="document(substring-before(concat($xsl-url,'?'),'?'))">
          <xsl:apply-templates select="." />
        </xsl:for-each>
      </xsl:when>
      <xsl:otherwise>
        <xsl:apply-imports />
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>
</xsl:stylesheet>