<?php
// include.xml contains :
// <child>test</child>
$xml = '<?xml version="1.0"?>
<root xmlns:xi="http://www.w3.org/2001/XInclude">
<xi:include href="include.xml">
<xi:fallback>
<error>xinclude: include.xml not found</error>
</xi:fallback>
</xi:include>
</root>';
$domxml = domxml_open_mem($xml);
$domxml->xinclude();
echo $domxml->dump_mem();
?>
The above example will output:
<?xml version="1.0"?>
<root xmlns:xi="http://www.w3.org/2001/XInclude">
<child>test</child>
</root>
If include.xml doesn't exist, you'll see:
<?xml version="1.0"?>
<root xmlns:xi="http://www.w3.org/2001/XInclude">
<error>xinclude:dom.xml not found</error>
</root>