Implementing Oauth2 login, Fatal error: Class 'Google_Service' not found

Question

I am updating my website\'s login system from LightOpenID to Google\'s Oauth 2.0.

When I require the Client.php and the Service/Oauth2.php I get an error

Answer 1

Make sure you add the line BEFORE any other Google "require_once" lines.

require_once 'google-api-php-client/autoload.php';

I had it last and it had me scratching my head for a good 10 minutes.