<?php
class A2Xml {
  private $version  = \'1.0\';
  private $encoding  = \'UTF-8\';
  private $root    = \'root\';
  private $xml    = null;
  function __construct() {
    $this->xml = new XmlWriter();
  }
  function toXml($data, $eIsArray=FALSE) {
    if(!$eIsArray) {
      $this->xml->openMemory();
      $this->xml->startDocument($this->version, $this->encoding);
      $this->xml->startElement($this->root);
    }
    foreach($data as $key => $value){
 
      if(is_array($value)){
        $this->xml->startElement($key);
        $this->toXml($value, TRUE);
        $this->xml->endElement();
        continue;
      }
      $this->xml->writeElement($key, $value);
    }
    if(!$eIsArray) {
      $this->xml->endElement();
      return $this->xml->outputMemory(true);
    }
  }
}
$res = array(
  \'hello\' => \'11212\',
  \'world\' => \'232323\',
  \'array\' => array(
    \'test\' => \'test\',
    \'b\'  => array(\'c\'=>\'c\', \'d\'=>\'d\')
  ),
  \'a\' => \'haha\'
);
$xml = new A2Xml();
echo $xml->toXml($res);