Sync Token Exception google-api-client-service php people Service - php

Question

I have a problem with the Google API. I need to get all the contacts of a user in my application, however I don't want to load all the data each time, because I store the data in my database.
It's why I want to use the Sync Token functionality which let's us get only data who has been changed since our last query.
For this i Use the Google APIs PHP client library.
I wrote my code and it throws an exception (Google_Service_Exception) which explains that my Sync Token is not valid anymore, so I decided to use a try/catch system to reset syncToken if it is not valid.
My problem is each time i made the request I go in the catch (the google_service_exception) is raised even if my token is valid.
I store the token in my database so I tested it in the API explorer here: https://developers.google.com/people/api/rest/v1/people.connections/list and it work fine, so I don't understand why my application doesn't work properly.
Here's my code:
$personFields = 'metadata,names,addresses,biographies,birthdays,emailAddresses,genders,memberships,organizations,phoneNumbers';
$user = $this->get('security.token_storage')->getToken()->getUser();
$syncToken = $user->getContactSyncToken();
$nextPagetoken = '';
$contactData = array();
$people_service = new \Google_Service_PeopleService($client);
do {
try {
$data = $people_service->people_connections->listPeopleConnections(
'people/me',
array(
'personFields' => $personFields,
'requestSyncToken' => true,
'syncToken' => $syncToken,
'pageToken' => $nextPagetoken,
)
);
}catch (\Google_Service_Exception $e){
$data = $people_service->people_connections->listPeopleConnections(
'people/me',
array(
'personFields' => $personFields,
'requestSyncToken' => true,
'syncToken' => '',
'pageToken' => $nextPagetoken,
)
);
}finally{
$syncToken = $data->getNextSyncToken();
$nextPagetoken = $data->getNextPageToken();
if (count($data->getConnections()) != 0) {
$contactData[] = $data->getConnections();
}
}
}while ($nextPagetoken !== null);
$user->setContactSyncToken($syncToken);
$this->getDoctrine()->getManager()->flush();
return $contactData;
Thank you for your help and sorry for my english i'm not a native and not very good at it.

Answer 1

Sorry i found the problem, in my User class i had:
public function getContactSyncToken()
{
if($token = $this->contactSyncToken !== null){
return $token;
}else{
return '';
}
}
And it always return ' ', now it works with:
public function getContactSyncToken()
{
$token = $this->contactSyncToken;
if($token !== null){
return $token;
}else{
return '';
}
}