Wie konvertiere ich einen XML-String in ein Array in PHP?

$obj = simplexml_load_string($str,"SimpleXMLElement", LIBXML_NOCDATA);

$json_str = json_encode($obj);

$xml_arr = json_decode($json_str, true);

$str = '
      
      
    1472549042
      
      
      
      
      
      
      
      
      
      
';

$obj = simplexml_load_string($str,"SimpleXMLElement", LIBXML_NOCDATA);
$test = json_decode(json_encode($obj),true);
$arr = [
    'FromUserName' => $test['FromUserName'],
    'ToUserName' => $test['ToUserName'],
    'CreateTime' => $test['CreateTime'],
    'CardId' => $test['CardId'],
    'UserCardCode' => $test['UserCardCode'],
    'ConsumeSource' => $test['ConsumeSource'],
    'StaffOpenId' => $test['StaffOpenId']
];
$arr = array_map('trim',$arr);
var_dump($arr);