private function session_expires()
{
if (!($last = $this->session->get(':LAST_ACTIVITY'))) {
$this->session->set(':LAST_ACTIVITY', time());
return false;
}
if ($this->timeout > 0 && time() - $last > $this->timeout) {
return true;
}
$this->session->set(':LAST_ACTIVITY', time());
return false;
}