public function clearSearchIndexAction()
    {
        // get uri builder
        $uriBuilder = GeneralUtility::makeInstance(UriBuilder::class);

        // admin only access
        if ($this->getBackendUser()->isAdmin()) {
            if ($this->do == 'clear') {
                $databaseConnection = Db::getDatabaseConnection('tx_kesearch_index');
                $databaseConnection->truncate('tx_kesearch_index');
            }
        }

        // build "clear index" link
        $moduleUrl = $uriBuilder->buildUriFromRoute(
            'web_KeSearchBackendModule',
            [
                'id' => $this->id,
                'do' => 'clear'
            ]
        );

        $this->view->assign('moduleUrl', $moduleUrl);
        $this->view->assign('isAdmin', $this->getBackendUser()->isAdmin());
        $this->view->assign('indexCount', $this->getNumberOfRecordsInIndex());

    }