/**
     * @return string
     */
    protected function startCourseOverWsdl()
    {
        $courseId    = ( isset( $_POST['courseid'] ) && filter_var($_POST['courseid'], FILTER_VALIDATE_REGEXP, SecurityTool::$ELEARNING_COURSEID_REGEXP) ) ? $_POST['courseid'] : null;
        
        $soapUrl            = SolrSafeOperatorHelper::feature('OnlineVortrageSettings', 'WsdlUrl');
        $credentialLogin    = SolrSafeOperatorHelper::feature('OnlineVortrageSettings', 'WsdlLogin');
        $credentialPassword = SolrSafeOperatorHelper::feature('OnlineVortrageSettings', 'WsdlPassword');
        $useLocale          = SolrSafeOperatorHelper::feature('OnlineVortrageSettings', 'UseLocale');
        $locale             = SolrSafeOperatorHelper::feature('OnlineVortrageSettings', 'Locale');
        
        $credentials = array(
            'login'    => $credentialLogin,
            'password' => $credentialPassword,
        );
        
        $params = array(
            array(
                'username' => MMUsers::getCurrentUserId(),
                'courseID' => $courseId,
            )
        );
        
        if ( $useLocale )
        {
            $params[0]['locale'] = $locale;
        }
        
        try
        {
            $soap   = new SoapClientAuth( $soapUrl, $credentials );
            $result = $soap->__soapCall( 'UnivadisEncrypt', $params );
            
            if ( isset($result) && isset($result->return) )
            {
                $url = $result->return;
                if ( strpos($url, 'http') !== 0 || strpos($url, 'https') !== 0)
                {
                    $url = 'http://' . $url;
                }
                
                if ( !ContextTool::instance()->isMobile() )
                {
                    $url = urlencode( urlencode( $url ) );
                    $url = '/external/deeplink?deeplink=' . $url . '&exit_strategy=0';
                }
                
                return $url;
            }
        }
        catch ( SoapFault $f )
        {
        }

        return false;
    }