Send email by Google API

I trying to send an email using Google API

Send email controller look as

    public function sendMessage()
    {
        $client = self::getClient();
        $service = new Google_Service_Gmail($client);
        $mailer = $service->users_messages;

        $message = (new Swift_Message('Here is my subject'))
            ->setFrom('[e-mail]')
            ->setTo(['[e-mail]' => 'Test Name'])
            ->setContentType('text/html')
            ->setCharset('utf-8')
            ->setBody('<h4>Here is my body</h4>');

        $msg_base64 = (new Swift_Mime_ContentEncoder_Base64ContentEncoder())
            ->encodeString($message->toString());

        $message = new Google_Service_Gmail_Message();
        $message->setRaw($msg_base64);
        $message = $mailer->send('me', $message);
        print_r($message);
    }

getClient class:

    function getClient()
    {
        $client = new Google_Client();
        $client->setRedirectUri('http://' . 'site.com' . '/oauth2callback.php');
        $client->setApplicationName('Gmail API PHP');
        $client->setScopes(Google_Service_Gmail::GMAIL_READONLY);
        $client->setAuthConfig('credentials.json');
        $client->setAccessType('offline');
        $client->setPrompt('select_account consent');
        return $client;
    }

When I’m trying to run this I receiving error:

{ "error": { "code": 401, "message": "Request is missing required authentication credential. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.", "errors": [ { "message": "Login Required.", "domain": "global", "reason": "required", "location": "Authorization", "locationType": "header" } ], "status": "UNAUTHENTICATED" } } 

credentials.json

{"web":{
  "client_id":"REDACTED",
  "project_id":"project-44",
  "auth_uri":"https://accounts.google.com/o/oauth2/auth",
  "token_uri":"https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url":"https://www.googleapis.com/oauth2/v1/certs",
  "client_secret":"redacted",
  "access_token":"redacted"}}

What can be wrong with my code? When I’m trying to print out $client it displays required data. Or how I shall to login to use it properly without interruptions? I’ve logged in before(several hours ago).

Answer

It looks like you’re missing the step where you obtain and/or set the access token or refresh token. In the PHP Quickstart for Gmail, it’s this chunk of code:

    // Load previously authorized token from a file, if it exists.
    // The file token.json stores the user's access and refresh tokens, and is
    // created automatically when the authorization flow completes for the first
    // time.
    $tokenPath = 'token.json';
    if (file_exists($tokenPath)) {
        $accessToken = json_decode(file_get_contents($tokenPath), true);
        $client->setAccessToken($accessToken);
    }

    // If there is no previous token or it's expired.
    if ($client->isAccessTokenExpired()) {
        // Refresh the token if possible, else fetch a new one.
        if ($client->getRefreshToken()) {
            $client->fetchAccessTokenWithRefreshToken($client->getRefreshToken());
        } else {
            // Request authorization from the user.
            $authUrl = $client->createAuthUrl();
            printf("Open the following link in your browser:n%sn", $authUrl);
            print 'Enter verification code: ';
            $authCode = trim(fgets(STDIN));

            // Exchange authorization code for an access token.
            $accessToken = $client->fetchAccessTokenWithAuthCode($authCode);
            $client->setAccessToken($accessToken);

            // Check to see if there was an error.
            if (array_key_exists('error', $accessToken)) {
                throw new Exception(join(', ', $accessToken));
            }
        }
        // Save the token to a file.
        if (!file_exists(dirname($tokenPath))) {
            mkdir(dirname($tokenPath), 0700, true);
        }
        file_put_contents($tokenPath, json_encode($client->getAccessToken()));
    }
    return $client;
}

To break it down a bit:

1. You need to request authorization from the user by sending them to the authorization URL ($client->createAuthUrl())
2. then exchange the code for an access token ($client->fetchAccessTokenWithAuthCode($authCode))
3. and either set it on your client ($client->setAccessToken($accessToken)) or save it for future use.

In addition to the access token, you’ll also want to save the refresh token that gets returned so you don’t have to re-login every time ($client->fetchAccessTokenWithRefreshToken($refreshToken)). If you’ve gone through this process already, it’s possible that your access token expired and you need to either use the refresh token or re-authenticate to get access again.

If you’re developing this application for more users than just yourself, you may want to look into managed OAuth platforms like Xkit, where I work. They handle the process of getting authorization, refreshing tokens, etc, along with encrypting the tokens and storing them for each individual user.