- define: documentation ( source)
<?php
define('XMLNS_TEST', 'http://example.org/test-ns');
$node = new SimpleXMLElement('<root></root>');
$node->addAttribute("i:somename", "somevalue", XMLNS_TEST);
$node->addChild("i:test", '', XMLNS_TEST);
$node->addChild("i:anotherTest", '', XMLNS_TEST);
echo $node->asXml();