/**
* Returns a user instance given the user name.
* @param string user name, null if it is a guest.
* @return TUser the user instance, null if the specified username is not in the user database.
*/
public function getUser($username = null)
{
if ($username === null) {
$user = new TUser($this);
$user->setIsGuest(true);
return $user;
} else {
$username = strtolower($username);
if (isset($this->_users[$username])) {
$user = new TUser($this);
$user->setName($username);
$user->setIsGuest(false);
if (isset($this->_roles[$username])) {
$user->setRoles($this->_roles[$username]);
}
return $user;
} else {
return null;
}
}
}