How to convert PHP associative multi-dimensional array to XML using DomConstructor

There are many solutions to accomplish PHP array to XML conversion, however many are complicated. I found this technique is the simplest. The function fromMixed below was written by Van de Voorde Toni. I hope this help someone.

This solution works for multi-dimensional array also.

$xmlDomConstructor_obj = new XmlDomConstructor('1.0', 'UTF-8');

$xmlRoot = $xmlDomConstructor_obj->createElement("WhatEverYourRootElement");
$xmlRoot = $xmlDomConstructor_obj->appendChild($xmlRoot);
$xmlDomConstructor_obj->fromMixed($your_associative_array, $xmlRoot);

$xml_output = $xmlDomConstructor_obj->saveXML();

To use the code above you need to include the class below (from Van de Voorde Toni):

<?
/**
 * Extends the DOMDocument to implement personal (utility) methods.
 * - From: http://www.devexp.eu/2009/04/11/php-domdocument-convert-array-to-xml/
 * - `parent::` See http://www.php.net/manual/en/class.domdocument.php
 *
 * @throws   DOMException   http://www.php.net/manual/en/class.domexception.php
 *
 * @author Toni Van de Voorde
 */
class XmlDomConstructor extends DOMDocument {

    /**
     * Constructs elements and texts from an array or string.
     * The array can contain an element's name in the index part
     * and an element's text in the value part.
     *
     * It can also creates an xml with the same element tagName on the same
     * level.
     *
     * ex:
        \verbatim
             <nodes>
                <node>text</node>
                <node>
                    <field>hello</field>
                    <field>world</field>
                </node>
             </nodes>
        \verbatim
     *
     *
     * Array should then look like:
        \verbatim
             array(
                "nodes" => array(
                    "node" => array(
                        0 => "text",
                        1 => array(
                            "field" => array (
                                0 => "hello",
                                1 => "world",
                            ),
                        ),
                    ),
                ),
             );
        \endverbatim
     *
     * @param mixed $mixed An array or string.
     *
     * @param DOMElement[optional] $domElement Then element
     * from where the array will be construct to.
     *
     */
    public function fromMixed($mixed, DOMElement $domElement = null) {

        $domElement = is_null($domElement) ? $this : $domElement;

        if (is_array($mixed)) {
            foreach( $mixed as $index => $mixedElement ) {

                if ( is_int($index) ) {
                    if ( $index == 0 ) {
                        $node = $domElement;
                    } 
                    else {
                        $node = $this->createElement($domElement->tagName);
                        $domElement->parentNode->appendChild($node);
                    }
                }
                else {
                    $node = $this->createElement($index);
                    $domElement->appendChild($node);
                }

                $this->fromMixed($mixedElement, $node);
            }
        } 
        else {
            $domElement->appendChild($this->createTextNode($mixed));
        }
    }
}