private function getReturnBaseUrl()
    {
        $baseUrl = '';

        /** @var TaoLtiSession $session */
        $session = \common_session_SessionManager::getSession();
        if ($session instanceof TaoLtiSession) {
            $launchData = $session->getLaunchData();
            if ($launchData->hasReturnUrl()) {
                $baseUrl = $launchData->getReturnUrl();
            }
        } else {
            if ($this->launchData->hasVariable(LtiLaunchData::LAUNCH_PRESENTATION_RETURN_URL)) {
                $baseUrl = $this->launchData->getVariable(LtiLaunchData::LAUNCH_PRESENTATION_RETURN_URL);
            }
        }

        return $baseUrl;
    }
private function getReturnBaseUrl()
    {
        $baseUrl = '';

        /** @var TaoLtiSession $session */
        $session = \common_session_SessionManager::getSession();
        if ($session instanceof TaoLtiSession) {
            $launchData = $session->getLaunchData();
            if ($launchData->hasReturnUrl()) {
                $baseUrl = $launchData->getReturnUrl();
            }
        } else {
            if ($this->launchData->hasVariable(LtiLaunchData::LAUNCH_PRESENTATION_RETURN_URL)) {
                $baseUrl = $this->launchData->getVariable(LtiLaunchData::LAUNCH_PRESENTATION_RETURN_URL);
            }
        }

        return $baseUrl;
    }
private function getReturnBaseUrl ( ) { $ baseUrl = '' ; /** @var TaoLtiSession $session */ $ session = \ common_session_SessionManager :: getSession ( ) ; if ( $ session instanceof TaoLtiSession ) { $ launchData = $ session -> getLaunchData ( ) ; if ( $ launchData -> hasReturnUrl ( ) ) { $ baseUrl = $ launchData -> getReturnUrl ( ) ; } } else { if ( $ this -> launchData -> hasVariable ( LtiLaunchData :: LAUNCH_PRESENTATION_RETURN_URL ) ) { $ baseUrl = $ this -> launchData -> getVariable ( LtiLaunchData :: LAUNCH_PRESENTATION_RETURN_URL ) ; } } return $ baseUrl ; }
Get lti return url from LTI session or from request data.

@return string
@throws LtiException
@throws \common_exception_Error
Get lti return url from LTI session or from request data .