uses generate-id() to add id to all elements in source XML. : generate id « XSLT stylesheet « XML Tutorial

1. XML Tutorial
2. XSLT stylesheet
3. generate id

File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<data>
    <AAA name="top">
      <BBB pos="1" val="bbb">11111</BBB>
      <BBB>22222</BBB>
    </AAA>
    <AAA name="bottom">
      <BBB>33333</BBB>
      <BBB>44444</BBB>
    </AAA>
</data>
File: Transform.xslt

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
      version="1.0"
      xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:template match="*">
      <xsl:copy>
        <xsl:attribute name="id"><xsl:value-of select="generate-id()"/></xsl:attribute>
        <xsl:for-each select="@*">
          <xsl:attribute name="{name()}"><xsl:value-of select="."/></xsl:attribute>
        </xsl:for-each>
        <xsl:apply-templates/>
      </xsl:copy>
    </xsl:template>
</xsl:stylesheet>  

Output:

<?xml version="1.0" encoding="UTF-8"?><data id="d2e1">
    <AAA id="d2e3" name="top">
      <BBB id="d2e5" pos="1" val="bbb">11111</BBB>
      <BBB id="d2e8">22222</BBB>
    </AAA>
    <AAA id="d2e12" name="bottom">
      <BBB id="d2e14">33333</BBB>
      <BBB id="d2e17">44444</BBB>
    </AAA>
</data>