In XSLT, generate-id() function returns a string that uniquely identifies the node in the node-set argument that is first in document order.
string generate-id(node-set?)
The unique identifier must consist of ASCII alphanumeric characters and must start with an alphabetic character. Thus, the string is syntactically an XML name. There is no guarantee that a generated unique identifier will be distinct from any unique IDs specified in the source document. If the node-set argument is empty, the empty string is returned. If the argument is omitted, it defaults to the context node.
Example
XML File (data.xml)
<?xml-stylesheet type="text/xsl" href="sample.xsl"?>
<catalog>
<book id="bk101">
<author>Gambardella, Matthew</author>
<title>XML Developer's Guide</title>
<genre>Computer</genre>
<price>44.95</price>
<publish_date>2000-10-01</publish_date>
<description>An in-depth look at creating applications with XML.</description>
</book>
<book id="bk102">
<author>Ralls, Kim</author>
<title>Midnight Rain</title>
<genre>Fantasy</genre>
<price>5.95</price>
<publish_date>2000-12-16</publish_date>
<description>A former architect battles corporate zombies.</description>
</book>
</catalog>
XSLT File (sample.xsl)
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:output method="html"/>
<xsl:template match="/">
<html>
<body>
<xsl:for-each select="//book">
<button id="{generate-id(author)}" onclick="alert(this.id)">
<xsl:value-of select="author"/>
</button>
</xsl:for-each>
</body>
</html>
</xsl:template>
</xsl:stylesheet>
The output:
This is the processor output:
<html>
<body><button id="IDAHAGJD" onclick="alert(this.id)">Gambardella, Matthew</button>
<button id="IDAPAGJD" onclick="alert(this.id)">Ralls, Kim</button></body>
</html>