问Google Calendar API，PHP，获取刷新令牌失败

EN

$client->setAssertionCredentials($cred);
if($client->getAuth()->isAccessTokenExpired()) {    
  $client->getAuth()->refreshTokenWithAssertion($cred);   
} 

                   // Refresh the token if it's expired.
                    if ($client->isAccessTokenExpired()) {
                        // save refresh token to some variable
                        $refreshTokenSaved = $client->getRefreshToken();

                        // update access token
                        $client->fetchAccessTokenWithRefreshToken($refreshTokenSaved);

                        // pass access token to some variable
                        $accessTokenUpdated = $client->getAccessToken();

                        // append refresh token
                        $accessTokenUpdated['refresh_token'] = $refreshTokenSaved;

                        // save to file
                        file_put_contents($credentialsPath, json_encode($accessTokenUpdated));
                    }

  <?php
require_once 'vendor/autoload.php';

/**
class to provide google calendar api functions.
returns information to mobile web app in json format
**/
class Calendar
{

    private $client;
    private $clientsecretgoogle = '{input secret here}';
    private $clientIDgoogle = '{input client ID here}';
    private $objDatabase;
    private $queryParams;
    private $params;

    public function __construct($params)
    {

        $this->client = new Google_Client();
        $this->client->setClientId($this->clientIDgoogle);
        $this->client->setClientSecret($this->clientsecretgoogle);
        $this->client->setAccessType('offline'); //this seems to be important for refresh tokens to update
        $this->objDatabase = new Database();//connect to dbase
        $this->params=$params;

    }

    public function getAuthorizationRefreshTokensGoogle($authCode, $userID)
    {

        /*
        Get access_token and refresh token from returned auth code
        I'm getting this on the front end and then storing in dbase table
        Could have used the basic php library here but this worked so I stuck with it
        */
        $oauth_url = 'https://www.googleapis.com/oauth2/v4/token?code=' . $authCode . '&client_secret=' . $this->clientsecretgoogle . '&client_id=' . $this->clientIDgoogle . '&redirect_uri=postmessage&grant_type=authorization_code';
        //using curl
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $oauth_url);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        $return = curl_exec($ch);

        curl_close($ch);
        $return = json_decode($return);
        // You can dump the vars to see the object
        //var_dump($return);

        //insert into table for later retrieval
         $strSQL = "insert ignore into tbloauth(oauth_usr_id,oauth_vendor,oauth_token,oauth_refresh_token,oauth_token_expire)VALUES
              (?,?,?,?,?)";
        //check for existence of refresh token in response
        //if not there then replace only the access_token
        //if there then replace access, refresh
        if(!$return->refresh_token){
            $strSQL .= "ON DUPLICATE KEY UPDATE oauth_token=VALUES(oauth_token), oauth_token_expire=VALUES(oauth_token_expire)";
        }else{
            $strSQL .= "ON DUPLICATE KEY UPDATE oauth_token=VALUES(oauth_token),oauth_refresh_token=VALUES(oauth_refresh_token), oauth_token_expire=VALUES(oauth_token_expire)";
         }
        //translate expire time NOW + 3600
        $expire = (time() + $return->expires_in);
        if (!$return->refresh_token) {
            $return->refresh_token = '';
        }

        $this->queryParams = array($userID, 'google', $return->access_token, $return->refresh_token, $expire);
        $this->objDatabase->insertQuery($strSQL, $this->queryParams);

        //you should now have a record now containing the access_token,refresh token, expire date

    }

   /*

   List calendars
   */
    function listCalendarsGoogle()
    {

        //1. Get tokens from database for the current user
        $result=$this->getUserAccessToken($this->params['usr_id'],'google');
        //2. Set access token with returned results
        $this->client->setAccessToken(json_encode($result[0]));

        //check for expired token and refresh if necessary
        if($this->client->isAccessTokenExpired()) {
            $this->client->refreshToken($result[0]['oauth_refresh_token']);
            $access_token = $this->client->getAccessToken();
            $strSQL="update tbloauth set oauth_token=? where oauth_vendor='google' and oauth_usr_id=? limit 1";
            $this->queryParams=array($access_token,$this->params['usr_id']);
            $this->objDatabase->updateQuery($strSQL,$this->queryParams);

        }

        //3.init calendar 
        $calendar = new Google_Service_Calendar($this->client);

        //4. list calendars of primary
        $calendarList = $calendar->calendarList->listCalendarList('primary');


        return json_encode($calendarList);


    }
    /**
    get access token for vendor(google in this case) using usr_id of user
    which is passed to the class from the web app

    */
    public function getUserAccessToken($usr_id,$vendor){

        $strSQL="select tbloauth.*,oauth_token as access_token,oauth_refresh_token as refresh_token from tbloauth where oauth_usr_id=? and oauth_vendor=? ";
        $this->queryParams=array($usr_id,$vendor);
        //echo $this->objDatabase->parms($strSQL,$this->queryParams);
        $aResult=$this->objDatabase->selectQuery($strSQL,$this->queryParams);
        $aResult[0]['client_id']=$this->clientIDgoogle;
        $aResult[0]['client_secret']=$this->clientsecretgoogle;
        return $aResult;


    }
    /**
    Insert Event into google using event info posted by web app

    */
    public function insertEventGoogle(){

        $result=$this->getUserAccessToken($this->params['usr_id'],'google');
        $this->client->setAccessToken(json_encode($result[0]));
        //check if expired
        //if expired then fetch new token with current token
        //update dbase with new token
        //this would be cleaner separated into another method
        //called before each list or insert calendar function

        if($this->client->isAccessTokenExpired()) {
            $this->client->refreshToken($result[0]['oauth_refresh_token']);
            $access_token = $this->client->getAccessToken();
            $strSQL="update tbloauth set oauth_token=? where oauth_vendor='google' and oauth_usr_id=? limit 1";
            $this->queryParams=array($access_token,$this->params['usr_id']);
            $this->objDatabase->updateQuery($strSQL,$this->queryParams);

        }

        //init calendar 
        $calendar = new Google_Service_Calendar($this->client);
        //event info
        $event = new Google_Service_Calendar_Event(array(
            'summary' => $this->params['event_name'],
            'location' => $this->params['event_location'],
            'description' => $this->params['event_desc'],
            'start' => array(
                'dateTime' => date(DATE_ISO8601, strtotime($this->params['event_start_date'].' '.$this->params['event_start_time'])),
                'timeZone' => 'America/New_York',
            ),
            'end' => array(
                'dateTime' => date(DATE_ISO8601, strtotime($this->params['event_end_date'].' '.$this->params['event_end_time'])),
                'timeZone' => 'America/New_York',
            ),
            'reminders' => array(
                'useDefault' => FALSE,
                'overrides' => array(
                    array('method' => 'email', 'minutes' => 24 * 60),
                    array('method' => 'popup', 'minutes' => 10),
                ),
            ),
        ));
        //calendar id - default primary
        $calendarId = 'primary';
        //insert event
        $event = $calendar->events->insert($calendarId, $event);
        //return confirm msg
        $msg=array('msg'=>'Event Created: '.$this->params['event_name']);
        return json_encode($msg);





    }
}