147   protected $session;  variable in Facebook
313    * @param Array $session the session
317   public function setSession($session=null, $write_cookie=true) {  argument
318     $session = $this->validateSessionObject($session);
320     $this->session = $session;
322       $this->setCookieFromSession($session);
335       $session = null;
342         $session = $this->createSessionFromSignedRequest($signedRequest);
346       if (!$session && isset($_REQUEST['session'])) {
347         $session = json_decode(
353         $session = $this->validateSessionObject($session);
357       if (!$session && $this->useCookieSupport()) {
360           $session = array();
366           ), $session);
367           $session = $this->validateSessionObject($session);
369           $write_cookie = empty($session);
373       $this->setSession($session, $write_cookie);
376     return $this->session;
385     $session = $this->getSession();
386     return $session ? $session['uid'] : null;
395     $session = $this->getSession();
397     if ($session) {
398       return $session['access_token'];
649    * @param Array $session the session to use for setting the cookie
651   protected function setCookieFromSession($session=null) {  argument
660     if ($session) {
661       $value = '"' . http_build_query($session, null, '&') . '"';
662       if (isset($session['base_domain'])) {
663         $domain = $session['base_domain'];
665       $expires = $session['expires'];
693    * @param Array $session the session object
696   protected function validateSessionObject($session) {  argument
698     if (is_array($session) &&
699         isset($session['uid']) &&
700         isset($session['access_token']) &&
701         isset($session['sig'])) {
703       $session_without_sig = $session;
709       if ($session['sig'] != $expected_sig) {
711         $session = null;
715       $session = null;
717     return $session;
734     $session = array(
741     $session['sig'] = self::generateSignature(
742       $session,
746     return $session;