Google URL Shortening API using PHP - google-api

Question

Now I know this is a common topic that has been over the Internet especially StackOverflow. But what I do not have (or haven't yet seen) is a straight solution for the token being maintained over a session.
I'm using the Google APIs Client Library for PHP .
My Query:
I have one index.php where I fetch the user data (such as name) using the Google_Oauth2Service from the PHP client lib. The user is authenticated successfully and all goes well. Now I'd like to use the URL Shortening service and therefore I have a shorten.php where I have the code to try fetch the short URL. Some how this doesn't work.
index.php
//include google api files
require_once 'src/Google_Client.php';
require_once 'src/contrib/Google_Oauth2Service.php';
require_once 'src/contrib/Google_UrlshortenerService.php';
//start session
session_start();
$gClient = new Google_Client();
$gClient->setApplicationName('Test App');
$gClient->setClientId($google_client_id);
$gClient->setClientSecret($google_client_secret);
$gClient->setRedirectUri($google_redirect_url);
$gClient->setDeveloperKey($google_developer_key);
$google_oauthV2 = new Google_Oauth2Service($gClient);
....
....
Here I have started the session and made an object of the Google_Client. I have declared the client id, secret and all other details.
Then I get the access token on successful authentication and store it in the Session variable so that when I try to fetch the short url (using jQuery ajax) from shorten.php, I can use the existing token.
$_SESSION['token'] = $gClient->getAccessToken();
....
Now in shorten.php
session_start();
require_once 'src/Google_Client.php';
require_once 'src/contrib/Google_Oauth2Service.php';
require_once 'src/contrib/Google_UrlshortenerService.php';
$gClient = new Google_Client();
$gClient->setApplicationName('Test App');
$gClient->setClientId($google_client_id);
$gClient->setClientSecret($google_client_secret);
$gClient->setRedirectUri($google_redirect_url);
$gClient->setDeveloperKey($google_developer_key);
....
if (isset($_SESSION['token']) && $_SESSION['token']) {
// Set the access token from the session
$gClient->setAccessToken($_SESSION['token']);
$url_service = new Google_UrlshortenerService($gClient);
// Check if a URL has been passed
if (isset($_GET['url'])) {
$url = new Google_Url();
$url->longUrl = $_GET['url'];
$shortURL = $url_service->url->insert($url);
....
This is the exact line where the code breaks $shortURL = $url_service->url->insert($url); I was successful in getting the token using the Session variable and created a successful URL Service object. But just when I call the insert method, that's when it fails.
From the apache error logs :
husain#innovate:~/myprojects/web$ tail -1 /var/log/apache2/error.log | sed -e 's/\\n/\n/g'
[Thu Mar 28 00:42:35 2013] [error] [client 127.0.0.1] PHP Fatal error: Uncaught exception 'Google_ServiceException' with message 'Error calling POST https://www.googleapis.com/urlshortener/v1/url?key=AIzaSyCxfXP-xS-QYJw-7mM4SNG3EW9ryj_Oiv4: (401) Invalid Credentials' in /home/husain/myprojects/web/apps/src/io/Google_REST.php:66
Stack trace:
#0 /home/husain/myprojects/web/apps/src/io/Google_REST.php(36): Google_REST::decodeHttpResponse(Object(Google_HttpRequest))
#1 /home/husain/myprojects/web/apps/src/service/Google_ServiceResource.php(177): Google_REST::execute(Object(Google_HttpRequest))
#2 /home/husain/myprojects/web/apps/src/contrib/Google_UrlshortenerService.php(38): Google_ServiceResource->__call('insert', Array)
#3 /home/husain/myprojects/web/apps/shorten.php(44): Google_UrlServiceResource->insert(Object(Google_Url))
#4 {main}
thrown in /home/husain/myprojects/web/apps/src/io/Google_REST.php on line 66
When I dump the Google_Client variables on the index.php and shorten.php files, this is what I get.
index.php
Google_Client Object
(
[scopes:protected] => Array
(
)
[useObjects:protected] =>
[services:protected] => Array
(
[oauth2] => Array
(
[scope] => Array
(
[0] => https://www.googleapis.com/auth/userinfo.profile
[1] => https://www.googleapis.com/auth/userinfo.email
)
)
)
[authenticated:Google_Client:private] =>
)
shorten.php
object(Google_Client)#1 (4) {
["scopes":protected]=>
array(0) {
}
["useObjects":protected]=>
bool(false)
["services":protected]=>
array(1) {
["urlshortener"]=>
array(1) {
["scope"]=>
string(44) "https://www.googleapis.com/auth/urlshortener"
}
}
["authenticated":"Google_Client":private]=>
bool(false)
}
and both aint the same so I'm assuming that there is something not right here. Help or direction please.

Answer 1

You're not requesting the UrlShortener scope when authenticating, that's why it's failing.
To get the scope added, you can create an UrlshortenerService before authenticating in index.php, passing the same instance of the client, as in:
//start session
session_start();
$gClient = new Google_Client();
$gClient->setApplicationName('Test App');
$gClient->setClientId($google_client_id);
$gClient->setClientSecret($google_client_secret);
$gClient->setRedirectUri($google_redirect_url);
$gClient->setDeveloperKey($google_developer_key);
$google_oauthV2 = new Google_Oauth2Service($gClient);
$url_service = new Google_UrlshortenerService($gClient);
Alternatively, you can use setScopes to override the automatically generated scope