<?php
$xml = <<<EOD
<?xml version="1.0" ?>
<chapter xmlns:xi="http://www.w3.org/2001/XInclude">
<title>Books of the other guy..</title>
<para>
<xi:include href="book.xml">
<xi:fallback>
<error>xinclude: book.xml not found</error>
</xi:fallback>
</xi:include>
</para>
</chapter>
EOD;
$dom = new DOMDocument;
// let's have a nice output
$dom->preserveWhiteSpace = false;
$dom->formatOutput = true;
// load the XML string defined above
$dom->loadXML($xml);
// substitute xincludes
$dom->xinclude();
echo $dom->saveXML();
?>
The above example will output
something similar to:
<?xml version="1.0"?>
<chapter xmlns:xi="http://www.w3.org/2001/XInclude">
<title>Books of the other guy..</title>
<para>
<row xml:base="/home/didou/book.xml">
<entry>The Grapes of Wrath</entry>
<entry>John Steinbeck</entry>
<entry>en</entry>
<entry>0140186409</entry>
</row>
<row xml:base="/home/didou/book.xml">
<entry>The Pearl</entry>
<entry>John Steinbeck</entry>
<entry>en</entry>
<entry>014017737X</entry>
</row>
<row xml:base="/home/didou/book.xml">
<entry>Samarcande</entry>
<entry>Amine Maalouf</entry>
<entry>fr</entry>
<entry>2253051209</entry>
</row>
</para>
</chapter>