XSLT, 2nd Edition

A Brute-Force Approach

One thing we could do is make the transformation in two passes; we could write an intermediate stylesheet to sort the names and generate a new XML document, and then use the stylesheet we’ve already written, because document order and sorted order will be the same. Here’s how that intermediate stylesheet would look:

<?xml version="1.0"?>
<!-- namegrouper2a.xsl -->
<xsl:stylesheet version="1.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

  <xsl:output method="xml" indent="no"/>

  <xsl:strip-space elements="*"/>

  <xsl:template match="/">
    <addressbook>
      <xsl:for-each select="addressbook/address">
        <xsl:sort select="name/zip"/>
        <xsl:copy-of select="."/>
      </xsl:for-each>
    </addressbook>
  </xsl:template>
</xsl:stylesheet>

This stylesheet generates a new <addressbook> document that has all of the <address> elements sorted correctly. We can then run our original stylesheet against the sorted document and get results that are closer to what we want:

Addresses grouped by zip code
Ms. Natalie Attired
707 Breitling Way


Zip code 02718 (Skunk Haven, MA):
Harry Backstayge
283 First Avenue

Mary Backstayge
283 First Avenue


Zip code 02930 (Lynn, MA):
Ms. Amanda Reckonwith
930-A Chestnut Street


Zip code 27318 (Boylston, VA):
Mary McGoon
103 Bryant Street


Zip code 48392 (Sheboygan, WI):
Mr. Chester Hasbrouck Frisby
1234 Main Street

There’s one more problem here: we don’t have a heading for the first group. Natalie Attired lives in Winter Harbor, Maine, but there’s no heading for Winter ...