How to get Google Contacts information using Google OAuth?

Question

I am new to OAuth, and want to create a page that gets the user's contact list from Google using the OAuth system so they don't have to login.

How do I do this? I am using php, so I would really appreciate if there is example code that does this. I can't seem to find it on Google.

Please help!

Thanks

Answer 1

For general OAuth principles to access Google, you might find Google's OAuth playground very useful (contacts are included there).

This is a very basic example (using the php oauth pecl extension and simplexml, it just prints out the names of the 25 first contacts):

<?php
$cons_key="your consumer key";
$cons_sec="your consumer secret";

$callback="http://".$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'];

$req_token_url="https://www.google.com/accounts/OAuthGetRequestToken";
$auth_token_url="https://www.google.com/accounts/OAuthAuthorizeToken";
$acc_token_url="https://www.google.com/accounts/OAuthGetAccessToken";

$scope="https://www.google.com/m8/feeds/";
$scopes=urlencode($scope);
$req_scope_token_url=$req_token_url."?scope=".$scopes;
$endpoint="https://www.google.com/m8/feeds/contacts/default/full/";

session_start();

if(!isset($_GET['oauth_token']) && $_SESSION['state']==1) $_SESSION['state'] = 0;

try {
    $oauth = new OAuth($cons_key,$cons_sec);
    if(!isset($_GET['oauth_token']) && !$_SESSION['state']) {
        $oauth = new OAuth($cons_key,$cons_sec);
        $oauth->setRequestEngine(OAUTH_REQENGINE_CURL);
        $request_token_info = $oauth->getRequestToken($req_scope_token_url,$callback);
        if(!empty($request_token_info)) {
            $_SESSION['token']=$request_token_info['oauth_token'];
            $_SESSION['secret']=$request_token_info['oauth_token_secret'];
            $_SESSION['state']=1;
            header('Location: '.$auth_token_url.'?oauth_token='.$_SESSION['token']);
            exit;
        }
    } else if($_SESSION['state']==1) {
        $oauth->setToken($_GET['oauth_token'],$_SESSION['secret']);
        $access_token_info = $oauth->getAccessToken($acc_token_url);
        $_SESSION['state'] = 2;
        $_SESSION['token'] = $access_token_info['oauth_token'];
        $_SESSION['secret'] = $access_token_info['oauth_token_secret'];
    }

    $oauth->fetch($endpoint);
    parseAtom($oauth->getLastResponse());

} catch(OAuthException $E) {
    print_r($E);
}

function parseAtom($atomstring) {
    global $oauth;
    $atom=simplexml_load_string($atomstring);
    foreach ($atom->entry as $entry) {
        print $entry->title.", ";
    }
}
?>

You can see the above code in action here.

Installing (configuring) the oauth pecl extension can be tricky, you may have to check your php.ini and/or specify a requestengine.

Answer 2

Hope my post helpful to all (Google contact list reader in PHP(Google OAuth)) http://anandafit.info/2011/03/08/google-contact-list-reader-in-php-google-oauth/