List of files from my google drive - google-drive-api

Question

I am writing PHP script which get files from my Google Drive folder and write list of them with download links on my website, but can not find solution which take files from my folder. Every solution I found need sign up from user, that is viewing page and get list of files from his google drive. Can anyone help me with solution?
Here is my code.
function printFilesInFolder($service, $folderId) {
$pageToken = NULL;
do {
try {
$parameters = array();
$parameters = array(
'q' => "'0B5NCdsbrL1VfQ00xY3pFS3BtOE0' in parents"
);
$children = $service->files->listFiles($parameters);
var_dump($children);
foreach ($children->getFiles() as $child) {
print 'File Id: ' . $child->getId();
}
$pageToken = $children->getNextPageToken();
} catch (Exception $e) {
print "An error occurred: " . $e->getMessage();
$pageToken = NULL;
}
} while ($pageToken);
}
$client = new Google_Client();
$client->setApplicationName("Web client 1");
$client->setClientId('CLIENTID');
$client->setClientSecret('SECRET');
$client->setScopes(array('https://www.googleapis.com/auth/drive.file'));
$client->setRedirectUri('http://localhost/googledrive/drive/drive.php');
if (isset($_GET['code']) || (isset($_SESSION['access_token']) && $_SESSION['access_token'])) {
if (isset($_GET['code'])) {
$client->authenticate($_GET['code']);
$_SESSION['access_token'] = $client->getAccessToken();
} else
$client->setAccessToken($_SESSION['access_token']);
$service = new Google_Service_Drive($client);
$ret = printFilesInFolder($service,"FOLDERID");
} else {
$authUrl = $client->createAuthUrl();
header('Location: ' . $authUrl);
exit();
}
But i still dont getting right data.
Second think is, that i want to remove need of authentication on every refresh of page, but i dont know how to do that.