<root>
    <user name="Cartman"/>
    <user name="Kyle"/>    
</root>

<?php
    $xml = new DomDocument();
    // $PATH = xml path
    $xml->load($PATH); 
    
    // get an element (NodeElement)
    $noeud_racine = $xml->getElementsByTagName('root')->item(0); 
    
    // get a list of elements (NodeList)
    $utilisateurs = $xml->getElementsByTagName('users'); 
    
    // create element
    $nouvel_element = $xml->createElement('plop'); 
    
    // navigate in nodeList
    foreach($child as $utilisateurs) 
    {
        // get an attribute value + displaying it
        echo $child->getAttribute('name'); 
        
        // add an attribut to an element
        $child->setAttribute('age', '12'); 
        
        // add a new node to another one
        $child->appendChild($nouvel_element);
    }
    
    // save xml file
    $xml->save($PATH); 
?>

/*
   - php.io.File.getContent($PATH) is used to get the content of a file
   - Xml.parse(string) is used to parse our string in a valid Xml
*/

// get the XML file
var xml = Xml.parse(php.io.File.getContent(XML_PATH)); 

// get the node root (the very first one)
var noeud_racine = xml.firstElement(); 

// get its childs
var utilisateurs = noeud_racine.elements(); 

// create a new element
var nouvel_element = Xml.createElement('plop'); 

// navigate through them
for(child in utilisateurs) 
{
    // get an attribute value
    trace(child.get('name')); 
    
    // set a new attribute value
    child.set('age', '12'); 
    
    // add a new child to our node
    child.addChild(nouvel_element); 
}

// save the xml file
php.io.File.putContent(XML_PATH, xml.toString());