为什么我无法通过PHP从Google OAuth API获取数据？

Question

I have a login script created which allows you to login through the Google API. Everything works fine and the redirect back to my website does also work.

Here is my script for the oauth callback:

<?php
require_once 'google-api-php-client-2.2.1/vendor/autoload.php';
session_start();

if (isset ($_GET["error"])) {

    header('Location: #');

} 

if (isset ($_GET["code"])) {

    $client = new Google_Client();  
    $client->authenticate($_GET['code']);
    $_SESSION['g_access_token'] = $client->getAccessToken();    


    $redirect = "http://".$_SERVER["HTTP_HOST"].$_SERVER["PHP_SELF"];
    header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
}

if (isset ($_SESSION["g_access_token"])) {

    $plus = new Google_Service_Plus($client);
    $client->setAccesToken($_SESSION["g_access_token"]);
    $me = $plus->people->get('me');

    $_SESSION["unid"] = $me["id"];
    $_SESSION["g_name"] = $me["displayName"];
    $_SESSION["email"] = $me["emails"][0]["value"];
    $_SESSION["g_profile_image_url"] = $me["image"]["url"];
    $_SESSION["g_cover_image_url"] = $me["cover"]["coverPhoto"]["url"];
    $_SESSION["g_profile_url"] = $me["url"];
}
?>

I dont get any error, but the session variables are still undefined. Where is the problem? I just read and watched lots of tutorials, but still dont get it. Maybe somebody can help me here!

Thank you :)

EDIT

I just debugged my code and now I know that the Session Variable 'g_access_token' is empty after the login. So the main reason why it doesnt work should be the authentication. But I still dont know how to solve that...

Answer 1

I've just come from dealing successfully with Google OAuth API for PHP. So far, your code doesn't seem broke. Anyhow, it'd be nice to check your config file from which you get the class new Google_Client().

As that file is not posted in your question, i recommend you to follow this one, and call it through require_once to whenever you need it:

<?php
    session_start();
    require_once "GoogleAPI/vendor/autoload.php";
    $gClient = new Google_Client();
    $gClient->setClientId("your_client_id_comes_here");
    $gClient->setClientSecret("your_client_secret");
    $gClient->setApplicationName("CPI Login Tutorial");
    $gClient->setRedirectUri("your_authorized_uri.php");
//addScope sets the permissions you'll have in your app, whether it is only for displaying them or to handle as you desire (e.g.: store account's information, such as email givenName and so on, into your own db
    $gClient->addScope("https://www.googleapis.com/auth/plus.login https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/plus.me");
?>

Also, don't you forget to enable the Google + API in your Google console. Finally, check that in your credentials, the "Authorized redirect URIs" contains the redirect uri you want the google api to callback once the user is authenticated.