Not Getting access token from of Gmail Contacts API using Oauth2 while code is in Google App Engine Server

Question

I am using zend-framework2 and google-app-engine server to import all gmail contact list. I am getting authorization code from gmail after login. When hitting curl using this authorization code to get access token, it gives blank array as response.

Also this app is a billed app in google-app-engine. and already set

extension = "curl.so"

in php.ini file. and the credentials which i have given are correct.

// Import Gmail Contacts
$client_id='xxxxxxxxxxxxxxxxxxxxxxxxxxxx.apps.googleusercontent.com'; 
$client_secret='xxxxxxxxxxxxxx-xxxxxxxxx';
$redirect_uri='http://xxxxxxxxxxxxxxx.appspot.com/u/invite/gmailCallback';
$max_results = 1000;
if(isset($_GET["code"]) && $_GET["code"] != '') {
    $auth_code = $_GET["code"];

    $fields=array(
        'code'=>  urlencode($auth_code),
        'client_id'=>  urlencode($client_id),
        'client_secret'=>  urlencode($client_secret),
        'redirect_uri'=>  urlencode($redirect_uri),
        'grant_type'=>  urlencode('authorization_code')
    );
    $post = '';
    foreach($fields as $key=>$value) { $post .= $key.'='.$value.'&'; }
    $post = rtrim($post,'&');

    $curl = curl_init();
    curl_setopt($curl,CURLOPT_URL,'https://accounts.google.com/o/oauth2/token');
    curl_setopt($curl,CURLOPT_POST,5);
    curl_setopt($curl,CURLOPT_POSTFIELDS,$post);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER,TRUE);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER,FALSE);
    $result = curl_exec($curl);
    //$info = curl_getinfo($curl);
    //echo "<pre>"; print_r($info); die;
    curl_close($curl);

    $response =  json_decode($result);
    //echo "<pre>"; var_dump($response); die;
    if(isset($response->access_token) && $response->access_token != '') {

        $accesstoken = $response->access_token;

        $url = 'https://www.google.com/m8/feeds/contacts/default/full?max-results='.$max_results.'&oauth_token='.$accesstoken;
        //$url = 'https://www.google.com/m8/feeds/contacts/default/full?oauth_token='.$accesstoken;
        $xmlresponse =  $this->curl_file_get_contents($url);

        //At times you get Authorization error from Google.
        if((strlen(stristr($xmlresponse,'Authorization required'))>0) && (strlen(stristr($xmlresponse,'Error '))>0)) {
            //$returnArr['error_msg'] = "Something went wrong to import contacts!!";
            echo '<h2>Something went wrong to import contacts !!</h2>';die;
        } else {
            $xml =  new SimpleXMLElement($xmlresponse);
            $xml->registerXPathNamespace('gd', 'http://schemas.google.com/g/2005');
            $result = $xml->xpath('//gd:email');
            //echo "<pre>"; print_r($result); die;
            foreach ($result as $title) {
                $emailsArr[] = (string) $title->attributes()->address;
            }
        }
    }

}

Please help.

Answer 1

From previous experience (and this answer) I don't think cURL is enabled on App Engine as C extensions aren't supported.

You'll have to use URL Fetch instead e.g.

$data = ['data' => 'this', 'data2' => 'that'];
$data = http_build_query($data);
$context = [
  'http' => [
    'method' => 'GET',
    'header' => "custom-header: custom-value\r\n" .
                "custom-header-two: custom-value-2\r\n",
    'content' => $data
  ]
];

$context = stream_context_create($context);
$result  = file_get_contents('http://app.com/path?query=update', false, $context);

Answer 2

App engine supports cURL, but it seems to be buggy. I have the same problem with OAuth authentication via Google. The POST cURL call just returns FALSE without any error message. Here is the official bug report: https://code.google.com/p/googleappengine/issues/detail?id=11985

What you can do now, is to switch to url fetch functions. To make a POST request you can use following function:

protected function _call($url, array $params, $method = 'GET', array $headers = [])
{        
    $query = http_build_query($params);

    $headers_str = '';

    if ($headers) {
        foreach ($headers as $name => $value) {
            $headers_str .= $name . ': ' . $value . "\r\n";
        }
    }

    $headers_str .= "Content-type: "."application/x-www-form-urlencoded"."\r\n";

    $options =
        array('http'=>
          array(
            'method' => $method,
            'header' => $headers_str,
            'content' => $query,
            'ignore_errors' => true,
          )
    );

    if ($method === 'POST') {
        $options['http']['content'] = $query;
    } else if ($query) {
        $url .= '?' . $query;
    }

    $context = stream_context_create($options);

    $response = file_get_contents($url, false, $context);

    // check for zipped response and decode it
    if (array_search('Content-Encoding: gzip', $http_response_header)) {
        $response = gzinflate(substr($response, 10, -8));
    }

    return $response;
}

Or you can try to use this cURL wrapper library https://github.com/azayarni/purl, which was implemented before GAE provided cURL support. Hope it is helpful:)