How to check if user is still logged in google? - laravel-5

Question

I am using Google OAuth through Laravel Socialite to authenticate all the users in my web app.
I need the user session to end as soon as possible if user logs out of his google account.
I am trying to set up a middleware that would perform regular checks if user is still signed in with google. But I can't find a way to ask "Is user#example.com still the current user on google?"
I tried to get \Socialite::driver('google')->user() in the middleware but that doesn't seem to work without doing a redirect to google beforehand. I would like this check to be as quick and unobtrusive as possible. It should also work during a background ajax call.
It seems that it would be trivial using the client side authentication as there is gapi.auth2.init().isSignedIn.get(). However, that would mean I have to ask users for two authorizations (server side and client side) which seems wrong.
Looking at the docs at google, I see nothing that would let me check their authentication status apart from reauthenticating. Access token won't expire on logout... Is there a workaround?

Answer 1

It turns out that we can actually use gapi javascript in tandem with Socialite - just use the same client token. I didn't suspect that I will just get all the info without logging in separately for browser session, but it works.
I added the following code to the end of my master blade template to check state for authorized users.
#auth
<script>
var currentUserEmail = '{{Auth::user()->email}}'; // user "sameness" criterion
var googleClientId = '{{env('GOOGLE_ID')}}'; // the same oauth client id
</script>
<script src="https://apis.google.com/js/platform.js"></script>
<script src="{{mix('js/checkGoogleAuth.js')}}"></script>
#endauth
The script checkGoogleAuth is a simple then, I copied the google tutorial and shortened it:
var auth2; // The Sign-In object.
var googleUser; // The current user.
/**
* Initializes Signin v2 and sets up listeners.
*/
var initSigninV2 = function() {
auth2 = gapi.auth2.init({
client_id: googleClientId,
scope: 'profile'
});
// Listen for sign-in state changes.
auth2.isSignedIn.listen(checkState);
auth2.currentUser.listen(checkState);
};
var checkState = function (user) {
//if signed out or changed user
if (!auth2.isSignedIn.get() || currentUserEmail != auth2.currentUser.get().getBasicProfile().getEmail())
$('.logout-username').click(); //click logout button
};
gapi.load('auth2', initSigninV2); //launch it
I hope it helps someone else as well!