Gmail API: How to get access token? - php

Question

I am testing the Gmail API.
So far I have done the following:
I have created the project in the Google Developers Console
I have enabled the Gmail API.
I have created a new Client ID and the client secret.
In my PHP script I have installed the PHP Client library and followed
the instructions for the setup in PHP.
So now when I run the file quickstart.php it gives a link. When I open it, it appears an authorization page where I authorize my application to access the Gmail API.
Then it redirects to the Redirect URIs that I have declared in the setup (adding the code parameter).
In the address bar it appears exactly this:
http://localhost/main/gmail_callback?code=MY_CODE
Where main is my controller and gmail_callback so far is just a blank function.
And it should be correct since these are my settings:
Javascript origins: http://localhost
Redirect URIs: http://localhost/main/gmail_callback
What do I do next?

Answer 1

The next step in the flow is to exchange the Authorization Code for an Access Token (which will also include a Refresh Token if you requested offline access). If you use the https://developers.google.com/oauthplayground/ to execute the flow manually, you'll be able to see the URLs involved. There is a php library call to do the same thing, but I personally prefer to send my own HTTP rather than use a library. Even if you do use a library, it will still be worth spending a little time to understand the HTTP flow so you can more easily debug any problems you encounter.

Answer 2

Basically I was approaching wrongly. Following these instructions is enough to get the tokens:
https://developers.google.com/gmail/api/quickstart/php
The main point is to access the file from the command line and not from the app.

Answer 3

I made a Oauth Gmail some months ago, I got something like this :
In my callback function :
if (! isset($_GET['code'])) {
$auth_url = $client->createAuthUrl();
return $this->redirect($auth_url);
} else {
$client->authenticate($_GET['code']);
$_SESSION['access_token'] = $client->getAccessToken();
$redirect_uri = Router::url('/', true).'Users/gmail';
return $this->redirect($redirect_uri);
}
And in my gmail() function :
public function gmail(){
require APPLIBS.'Google/src/Google'.DS.'autoload.php';
$client = new Google_Client();
$client->setAuthConfigFile('../Config/client_secrets.json');
$client->addScope(Google_Service_Oauth2::PLUS_LOGIN);
$client->addScope(Google_Service_Oauth2::USERINFO_EMAIL);
if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
$client->setAccessToken($_SESSION['access_token']);
$oauth_service = new Google_Service_Oauth2($client);
$data['Profile']['last_name'] = $oauth_service->userinfo->get()->familyName;
}
}
$data['Profile']['last_name'] contain the last_name of the user, for example.