idref — Extract IDREF from a linking element


The idref template accepts any xref or universally linking element as a parameter and returns the local ID that it points to. If it has a linkend attribute, it returns that value. If it has a xlink:href, it returns that value, parsed as needed to extract just the id reference. Otherwise it returns an empty string.

<xsl:template name="idref">
  <xsl:param name="xref" select="."></xsl:param>
  <xsl:param name="linkend" select="$xref/@linkend"></xsl:param>
  <xsl:param name="xpointer">
    <xsl:call-template name="xpointer.idref">
      <xsl:with-param name="xpointer" select="$xref/@xlink:href"></xsl:with-param>

    <xsl:when test="string-length($linkend) != 0">
      <xsl:value-of select="$linkend"></xsl:value-of>
    <xsl:when test="string-length($xpointer) != 0">
      <xsl:value-of select="$xpointer"></xsl:value-of>
    <!-- otherwise it's a pointer to some other document -->