<?php/** * UserIdentity represents the data needed to identity a user. * It contains the authentication method that checks if the provided * data can identity the user. */classUserIdentityextendsCUserIdentity{/** * Validates the username and password. * This method should check the validity of the provided username * and password in some way. In case of any authentication failure, * set errorCode and errorMessage with appropriate values and return false. * @param string username * @param string password * @return boolean whether the username and password are valid */publicfunctionauthenticate(){if($this->username==='demo'&&$this->password==='demo')$this->errorCode=self::ERROR_NONE;else$this->errorCode=self::ERROR_PASSWORD_INVALID;return!$this->errorCode;}}