I try to use google API php library PHP for oauth, and the official code as the follows:
$client = new Google_Client();
$client->setAuthConfig('client_secrets.json');
$client->setAccessType("offline"); // offline access
$client->setIncludeGrantedScopes(true); // incremental auth
$client->addScope(Google_Service_Drive::DRIVE_METADATA_READONLY);
$client->setRedirectUri('http://' . $_SERVER['HTTP_HOST'] .'/oauth2callback.php');
But I found the downloaded 'client_secrets.json' already contains redirectURI, and I found the oauth in the app can work without calling $client->setRedirectUri :
$client = new Google_Client();
$client->setAuthConfig('client_secrets.json');
$client->setAccessType("offline"); // offline access
$client->setIncludeGrantedScopes(true); // incremental auth
$client->addScope(Google_Service_Drive::DRIVE_METADATA_READONLY);
so my question is, what is the usage to call
$client->setRedirectUri
?