function XML2Array(SimpleXMLElement $parent)
{
    $array = array();

    foreach ($parent as $name => $element) {
        ($node = & $array[$name])
            && (1 === count($node) ? $node = array($node) : 1)
            && $node = & $node[];

        $node = $element->count() ? XML2Array($element) : trim($element);
    }

    return $array;
}

$xml   = simplexml_load_string($buffer);
$array = XML2Array($xml);
$array = array($xml->getName() => $array);