Example 1. Substituting Xincludes
<?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>  |