quick example

gistfile1.php

<?php
require_once app_path().'/libraries/google-api-php-client/src/Google_Client.php';
require_once app_path().'/libraries/google-api-php-client/src/contrib/Google_AnalyticsService.php';

session_start();

$client = new Google_Client();
$client->setApplicationName("Google Analytics PHP Starter Application");

// Visit https://code.google.com/apis/console?api=analytics to generate your
// client id, client secret, and to register your redirect uri.
$client->setClientId('xxxxxxxx');
$client->setClientSecret('xxxxxxxxxxx');
$client->setRedirectUri('http://localhost');
$client->setDeveloperKey('xxxxxxxxxx');
$service = new Google_AnalyticsService($client);

if (isset($_GET['logout'])) {
    unset($_SESSION['token']);
}

if (isset($_GET['code'])) {
	$client->authenticate();
	$_SESSION['token'] = $client->getAccessToken();
	$redirect = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];
	header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
}

if (isset($_SESSION['token'])) {
	$client->setAccessToken($_SESSION['token']);
}

if ($client->getAccessToken())
{
	$analytics = $service->data_ga->get('ga:(viewid)', '2012-01-01', date("Y-m-d"), 'ga:visits,ga:pageviews');
	echo '<pre>'.print_r($analytics,true).'</pre>';

	// you'll need to save the access and refresh token to the database to access without user action
    $_SESSION['token'] = $client->getAccessToken();

} else {
	$authUrl = $client->createAuthUrl();
	print "<a class='login' href='$authUrl'>Connect Me!</a>";
}

//echo '<pre>'.print_r($_SESSION,true).'</pre>';