$client->setApplicationName("Client_Library_Examples"); $service = new Postman_Google_Service_Books($client); /************************************************ If we have an access token, we can carry on. Otherwise, we'll get one with the help of an assertion credential. In other examples the list of scopes was managed by the Client, but here we have to list them manually. We also supply the service account ************************************************/ if (isset($_SESSION['service_token'])) { $client->setAccessToken($_SESSION['service_token']); } $key = file_get_contents($key_file_location); $cred = new Postman_Google_Auth_AssertionCredentials($service_account_name, array('https://www.googleapis.com/auth/books'), $key); $client->setAssertionCredentials($cred); if ($client->getAuth()->isAccessTokenExpired()) { $client->getAuth()->refreshTokenWithAssertion($cred); } $_SESSION['service_token'] = $client->getAccessToken(); /************************************************ We're just going to make the same call as in the simple query as an example. ************************************************/ $optParams = array('filter' => 'free-ebooks'); $results = $service->volumes->listVolumes('Henry David Thoreau', $optParams); echo "<h3>Results Of Call:</h3>"; foreach ($results as $item) { echo $item['volumeInfo']['title'], "<br /> \n"; } echo pageFooter(__FILE__);