Question

Hello I am new to xml and would like to compare some values using an xsl stylesheet

`<a>
 <b>   <name>foo</name>   </b>
 <b>   <name>bar</name>   </b>
 <b>   <name>fred</name>  </b>
 <b>   <name>fred</name>  </b>
 </a>`

I would like to write a style sheet that checks all the b nodes and returns the values that have the same value so using the simple example above i would like the output to resemble :
“Your duplicate strings are fred”

I have used a for each loop to return all the values but comparing the names and returning the duplicates has eluded me.If possible i would like to achieve the comparison by the use of a while type loop.

Thank you for any help.

Answer 1

An <xsl:key>-based solution:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:key name="kName" match="b/name" use="text()" />

  <xsl:template match="/">
    <xsl:for-each select="//b/name">
      <xsl:if test="count(key('kName', text())) &gt; 1">
        <xsl:value-of select="concat('Your duplicate is: ', text(), '&#xA;')" />
      </xsl:if>
    </xsl:for-each>
  </xsl:template>
</xsl:stylesheet>

For large input documents this will be more efficient than a solution that uses a preceding:: check.