xml2array

$xml = json_decode(json_encode(simplexml_load_file($data_file)), true);

$data = [];
foreach ($xml as $key => $many) {
    foreach ($many as $one) {
        foreach ($one as $item) {
            $attributes = $item['@attributes'];
            if (isset($attributes['id'])) {
                $data[$key][$attributes['id']] = array_merge($attributes, $item);
            } else {
                $data[$key][] = array_merge($attributes, $item);
            }
        }
    }
    unset($xml[$key]);
}
unset($xml);