Initial commit - Typo3 11.5.41

typo3conf/ext/lfeditor/Classes/Controller/AbstractBackendController.php

@@ -0,0 +1,236 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use TYPO3\CMS\Backend\Template\ModuleTemplate;
+use TYPO3\CMS\Core\Authentication\BackendUserAuthentication;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\View\ViewInterface;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * Abstract Backend Controller
+ */
+abstract class AbstractBackendController extends AbstractController {
+	/**
+	 * @var BackendUserAuthentication
+	 */
+	protected $backendUser;
+
+	/**
+	 * @var ?ModuleTemplate
+	 */
+	protected $moduleTemplate = NULL;
+
+	/**
+	 * Initializes any action
+	 *
+	 * @return void
+	 * @throws \SGalinski\Lfeditor\Exceptions\DirectoryAccessRightsException
+	 */
+	public function initializeAction() {
+		parent::initializeAction();
+
+		if (\TYPO3\CMS\Core\Http\ApplicationType::fromRequest($GLOBALS['TYPO3_REQUEST'])->isBackend()) {
+			$this->backendUser = $GLOBALS['BE_USER'];
+		}
+
+		$editingMode = $this->session->getDataByKey('editingMode');
+		$availableEditingModes = $this->configurationService->getAvailableEditingModes();
+		if ($this->backendUser->isAdmin()) {
+			if (!\array_key_exists($editingMode, $availableEditingModes)) {
+				$firstAvailableEditMode = \key($availableEditingModes);
+				$this->session->setDataByKey('editingMode', $firstAvailableEditMode);
+			}
+			$canChangeEditingModes = \count($availableEditingModes) > 0;
+		} else {
+			$canChangeEditingModes = \count($availableEditingModes) > 0
+				&& $this->backendUser->user['lfeditor_change_editing_modes'] !== 0;
+			if (!$canChangeEditingModes || !\array_key_exists($editingMode, $availableEditingModes)) {
+				$lastAvailableEditMode = array_key_last($availableEditingModes);
+				$this->session->setDataByKey('editingMode', $lastAvailableEditMode);
+			}
+		}
+
+		$this->session->setDataByKey('defaultLanguagePermission', $this->backendUser->checkLanguageAccess(0));
+		$this->session->setDataByKey('canChangeEditingModes', $canChangeEditingModes);
+	}
+
+	/**
+	 * Saves the the last called controller/action pair into the backend user
+	 * configuration if available
+	 *
+	 * @param bool $saveWithRedirectPair
+	 * @return void
+	 */
+	protected function setLastCalledControllerActionPair($saveWithRedirectPair = TRUE) {
+		if (!$this->backendUser) {
+			return;
+		}
+
+		$extensionKey = $this->request->getControllerExtensionKey();
+		$pair = [
+			'action' => $this->request->getControllerActionName(),
+			'controller' => $this->request->getControllerName(),
+		];
+
+		$this->backendUser->uc[$extensionKey . 'State']['LastActionControllerPair'] = $pair;
+		if ($saveWithRedirectPair) {
+			$this->backendUser->uc[$extensionKey . 'State']['LastActionControllerPairForRedirect'] = $pair;
+		}
+		$this->backendUser->writeUC($this->backendUser->uc);
+	}
+
+	/**
+	 * Resets the last called controller/action pair combination from the
+	 * backend user session
+	 *
+	 * @return void
+	 */
+	protected function resetLastCalledControllerActionPair() {
+		if (!$this->backendUser) {
+			return;
+		}
+
+		$extensionKey = $this->request->getControllerExtensionKey();
+		$this->backendUser->uc[$extensionKey . 'State']['LastActionControllerPair'] = [];
+		$this->backendUser->uc[$extensionKey . 'State']['LastActionControllerPairForRedirect'] = [];
+		$this->backendUser->writeUC($this->backendUser->uc);
+
+		if ($this->view instanceof ViewInterface) {
+			$this->view->assign('lastCalledControllerActionPair', NULL);
+		}
+	}
+
+	/**
+	 * Returns the last called controller/action pair from the backend user session
+	 *
+	 * @return array
+	 */
+	protected function getLastCalledControllerActionPair() {
+		if (!$this->backendUser) {
+			return [];
+		}
+
+		$extensionKey = $this->request->getControllerExtensionKey();
+		$state = $this->backendUser->uc[$extensionKey . 'State']['LastActionControllerPair'];
+		return (!\is_array($state) ? [] : $state);
+	}
+
+	/**
+	 * Returns the last called controller/action pair from the backend user session
+	 *
+	 * @return array
+	 */
+	protected function getLastCalledControllerActionPairForRedirect() {
+		if (!$this->backendUser) {
+			return [];
+		}
+
+		$extensionKey = $this->request->getControllerExtensionKey();
+		return $this->backendUser->uc[$extensionKey . 'State']['LastActionControllerPairForRedirect'] ?? [];
+	}
+
+	/**
+	 * Redirects to the last called controller/action pair saved inside the
+	 * backend user session
+	 *
+	 * @return \TYPO3\CMS\Extbase\Http\ForwardResponse|null
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	protected function redirectToLastCalledControllerActionPair(): ?\TYPO3\CMS\Extbase\Http\ForwardResponse {
+		$state = $this->getLastCalledControllerActionPairForRedirect();
+		if (\count($state) && \trim($state['action']) !== '' && \trim($state['controller']) !== '') {
+			$currentAction = $this->request->getControllerActionName();
+			$currentController = $this->request->getControllerName();
+			if (!($currentController === $state['controller'] && $currentAction === $state['action'])) {
+				$extensionName = $this->request->getControllerExtensionName();
+				$moduleSignature = $this->request->getPluginName();
+				$extensionConfig = $GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['extbase']['extensions'][$extensionName];
+				$availableControllers = $extensionConfig['modules'][$moduleSignature]['controllers'];
+				$controllerExists = isset($availableControllers[$state['controller']]);
+				if ($controllerExists) {
+					$actionExists = \in_array(
+						$state['action'],
+						$availableControllers[$state['controller']]['actions'],
+						TRUE
+					);
+					if ($actionExists) {
+						if (version_compare(
+							\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(),
+							'11.0.0',
+							'<'
+						)) {
+							$this->forward($state['action'], $state['controller']);
+						}
+
+						return (new \TYPO3\CMS\Extbase\Http\ForwardResponse($state['action']))->withControllerName(
+							$state['controller']
+						);
+					}
+				}
+			}
+		}
+		return NULL;
+	}
+
+	/**
+	 * Sets last called controller-action pair and assigns common view variables.
+	 * This function should be called at the end of actions which render view
+	 * (and does not do redirection or forwarding at the end)
+	 */
+	protected function commonViewRenderingActionSettings() {
+		$this->setLastCalledControllerActionPair();
+		$this->view->assign('editingMode', $this->session->getDataByKey('editingMode'));
+		$this->view->assign('editingModeOptions', $this->configurationService->getAvailableEditingModes());
+		$this->view->assign('adminUser', $this->backendUser->isAdmin());
+		$this->view->assign('defaultLanguagePermission', $this->session->getDataByKey('defaultLanguagePermission'));
+		$this->view->assign('canChangeEditingModes', $this->session->getDataByKey('canChangeEditingModes'));
+	}
+
+	/**
+	 * Since we cannot use constructor Injection, we do have to get one dynamically. If we want to use
+	 * our ModuleTemplate, call GetModuleTemplate before, which will init one if there is none for some reason
+	 */
+	protected function getModuleTemplate() {
+		if ($this->moduleTemplate === NULL) {
+			$moduleTemplateFactory = GeneralUtility::makeInstance(
+				\TYPO3\CMS\Backend\Template\ModuleTemplateFactory::class
+			);
+			$this->moduleTemplate = $moduleTemplateFactory->create($this->request);
+		}
+	}
+
+	/**
+	 * Use the ModuleTemplateResponse to create a response object for the backend
+	 *
+	 * @return  \Psr\Http\Message\ResponseInterface
+	 */
+	protected function createBackendResponse(): \Psr\Http\Message\ResponseInterface {
+		return $this->htmlResponse($this->view->render());
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/AbstractController.php

@@ -0,0 +1,317 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use SGalinski\Lfeditor\Service\BackupService;
+use SGalinski\Lfeditor\Service\ConfigurationService;
+use SGalinski\Lfeditor\Session\PhpSession;
+use TYPO3\CMS\Core\Cache\CacheManager;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * Abstract Controller
+ */
+abstract class AbstractController extends ActionController {
+	/**
+	 * @var \SGalinski\Lfeditor\Session\PhpSession
+	 */
+	protected $session;
+
+	/**
+	 *
+	 * @var ConfigurationService
+	 */
+	protected $configurationService;
+
+	/**
+	 * Inject the ConfigurationService
+	 *
+	 * @param ConfigurationService $configurationService
+	 */
+	public function injectConfigurationService(ConfigurationService $configurationService) {
+		$this->configurationService = $configurationService;
+	}
+
+	/**
+	 *
+	 * @var BackupService
+	 */
+	protected $backupService;
+
+	/**
+	 * Inject the BackupService
+	 *
+	 * @param BackupService $backupService
+	 */
+	public function injectBackupService(BackupService $backupService) {
+		$this->backupService = $backupService;
+	}
+
+	/**
+	 * Initializes the actions.
+	 * - Initializes the session object.
+	 * - Fetches configuration.
+	 *
+	 * @return void
+	 * @throws \SGalinski\Lfeditor\Exceptions\DirectoryAccessRightsException
+	 */
+	public function initializeAction() {
+		parent::initializeAction();
+		if (!($this->session instanceof PhpSession)) {
+			$this->session = GeneralUtility::makeInstance(PhpSession::class);
+			$this->session->setSessionKey('tx_lfeditor_sessionVariables');
+		}
+		$this->configurationService->prepareConfig();
+	}
+
+	/**
+	 * Saves in session currently selected values of select tags.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $referenceLanguageSelection
+	 * @param string $constantSelection
+	 * @param string $languageSelection
+	 * @param string $constantTypeSelection
+	 * @param string $bottomReferenceLanguageSelection
+	 * @param string $numSiteConstsSelection
+	 * @param string $extkey
+	 * @return void
+	 */
+	protected function saveSelectionsInSession(
+		$extensionSelection = NULL,
+		$languageFileSelection = NULL,
+		$referenceLanguageSelection = NULL,
+		$constantSelection = NULL,
+		$languageSelection = NULL,
+		$constantTypeSelection = NULL,
+		$bottomReferenceLanguageSelection = NULL,
+		$numSiteConstsSelection = NULL,
+		$extkey = NULL
+	) {
+		/* Extension/language file select box can't be unselected.
+		Only situation when $extensionSelection === NULL is when the form is submitted by
+		selection change of some other box. That is because <f:be.menus.actionMenu> with 'optgroup' tags is used */
+		if ($extensionSelection) {
+			$this->session->setDataByKey('extensionSelection', $extensionSelection);
+		}
+		if ($languageFileSelection) {
+			$this->session->setDataByKey('languageFileSelection', $languageFileSelection);
+		}
+		if ($referenceLanguageSelection) {
+			$this->session->setDataByKey('referenceLanguageSelection', $referenceLanguageSelection);
+		}
+		if ($constantSelection) {
+			$this->session->setDataByKey('constantSelection', $constantSelection);
+		}
+		if ($languageSelection) {
+			$this->session->setDataByKey('languageSelection', $languageSelection);
+		}
+		if ($constantTypeSelection) {
+			$this->session->setDataByKey('constantTypeSelection', $constantTypeSelection);
+		}
+		if ($bottomReferenceLanguageSelection) {
+			$this->session->setDataByKey('bottomReferenceLanguageSelection', $bottomReferenceLanguageSelection);
+		}
+		if ($numSiteConstsSelection) {
+			$this->session->setDataByKey('numSiteConstsSelection', $numSiteConstsSelection);
+		}
+		if ($extkey) {
+			$this->session->setDataByKey('extkey', $extkey);
+		}
+	}
+
+	/**
+	 * Assigns view width menu options and default menu selection which is fetched from session.
+	 *
+	 * @param string $menuName Name of the menu, which will be used as prefix of view keys for menu options and menu selection.
+	 * Example: menuName 'extension' will produce view keys 'extensionOptions' and 'extensionSelection'
+	 * @param array $options menu options to be assigned to view
+	 * @return void
+	 */
+	protected function assignViewWidthMenuVariables($menuName, $options) {
+		$this->view->assign($menuName . 'Options', $options);
+
+		$selection = $this->checkMenuSelection($menuName, $options);
+		$this->view->assign($menuName . 'Selection', $selection);
+	}
+
+	/**
+	 * Checks does selection exists in session or among menu options and if it does not,
+	 * first option becomes selected.
+	 *
+	 * @param string $menuName Name of the menu, which will be used as prefix of view keys for menu options and menu selection.
+	 * Example: menuName 'extension' will produce view keys 'extensionOptions' and 'extensionSelection'
+	 * @param array $options menu options to be checked upon.
+	 * @return string
+	 */
+	protected function checkMenuSelection($menuName, array $options) {
+		$selection = $this->session->getDataByKey($menuName . 'Selection');
+		if (!\array_key_exists($selection, $options)) {
+			$selection = NULL;
+		}
+		if ($selection === NULL && !empty($options)) {
+			$selection = array_key_first($options);
+			$this->session->setDataByKey($menuName . 'Selection', $selection);
+			return $selection;
+		}
+		return $selection;
+	}
+
+	/**
+	 * Sets FlashMessage from LFException.
+	 *
+	 * @param LFException $lFException
+	 * @return void
+	 */
+	public function addLFEFlashMessage(LFException $lFException) {
+		if ($lFException->getCode() === 0) {
+			$this->addFlashMessage(
+				$lFException->getMessage(),
+				LocalizationUtility::translate('failure.failure', 'lfeditor'),
+				AbstractMessage::ERROR
+			);
+		} elseif ($lFException->getCode() === 1) {
+			$this->addFlashMessage(
+				$lFException->getMessage(),
+				'',
+				AbstractMessage::NOTICE
+			);
+		}
+	}
+
+	/**
+	 * Prepares language file select options for each extension and sets combined data in view.
+	 *
+	 * @return void
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws LFException
+	 */
+	protected function prepareExtensionAndLangFileOptions() {
+		/** @var CacheManager $cacheManager */
+		$cacheManager = GeneralUtility::makeInstance(CacheManager::class);
+		$extensions = $cacheManager->getCache('lfeditor_select_options_cache')->get('extensionAndLangFileOptions');
+		if (!is_array($extensions)) {
+			$extensions = [];
+			$extensionOptions = $this->configurationService->menuExtList();
+			$extensionGroupCount = 0;
+			foreach ($extensionOptions as $extAddress => $extLabel) {
+				$extension['extKey'] = $extLabel;
+				((int) ExtensionManagementUtility::isLoaded(basename($extLabel))) ?
+					$state = LocalizationUtility::translate('ext.loaded', 'lfeditor') :
+					$state = LocalizationUtility::translate('ext.notLoaded', 'lfeditor');
+				$extension['extLabel'] = $extLabel . ' [' . $state . ']';
+
+				$extension['languageFileOptions'] = [];
+				$isExtensionGroupStart = $extAddress === '###extensionGroup###' . $extLabel;
+				try {
+					if (!$isExtensionGroupStart) {
+						$extension['languageFileOptions'] = $this->configurationService->menuLangFileList($extAddress);
+						if (empty($extension['languageFileOptions'])) {
+							continue;
+						}
+					} elseif (++$extensionGroupCount > 1) {
+						$extensions[$extAddress . 'EmptySpaceBefore'] = [
+							'extLabel' => '',
+							'languageFileOptions' => [],
+						];
+					}
+				} catch (LFException $e) {
+					continue;
+				}
+				$extensions[$extAddress] = $extension;
+
+				if ($isExtensionGroupStart) {
+					$extensions[$extAddress . 'DelimiterAfter'] = [
+						'extLabel' => '======',
+						'languageFileOptions' => [],
+					];
+				}
+			}
+			$cacheManager->getCache('lfeditor_select_options_cache')->set('extensionAndLangFileOptions', $extensions);
+		}
+		$this->checkExtensionAndLangFileSelection($extensions);
+		$extensionSelection = $this->session->getDataByKey('extensionSelection');
+
+		$this->view->assign('extensions', $extensions);
+		$this->view->assign('extensionSelection', $extensionSelection);
+		$this->view->assign('extensionLabel', $extensions[$extensionSelection]['extLabel'] ?? '');
+		$this->view->assign('languageFileSelection', $this->session->getDataByKey('languageFileSelection'));
+	}
+
+	/**
+	 * Checks do extensionSelection and languageFileSelection exist in session or among menu options and if it does not,
+	 * first language file and belonging extension become selected and saved to session.
+	 *
+	 * @param array $extensions
+	 * @return void
+	 */
+	protected function checkExtensionAndLangFileSelection(array $extensions) {
+		$extensionSelection = $this->session->getDataByKey('extensionSelection');
+		$languageFileSelection = $this->session->getDataByKey('languageFileSelection');
+
+		$selectFirstLanguageFileAndBelongingExtension = !$extensionSelection || !$languageFileSelection ||
+			!(array_key_exists($extensionSelection, $extensions) && array_key_exists(
+				$languageFileSelection,
+				$extensions[$extensionSelection]['languageFileOptions']
+			));
+		if ($selectFirstLanguageFileAndBelongingExtension) {
+			foreach ($extensions as $extAddress => $extension) {
+				if (empty($extension['languageFileOptions'])) {
+					continue;
+				}
+				$languageFileSelection = array_key_first($extension['languageFileOptions']);
+				$this->session->setDataByKey('languageFileSelection', $languageFileSelection);
+				$this->session->setDataByKey('extensionSelection', $extAddress);
+				break;
+			}
+		}
+	}
+
+	/**
+	 * Clears cache used for storing select options.
+	 * If $identifier is set, it clears only that entry in cache,
+	 * otherwise it clears whole select options cache.
+	 *
+	 * @param string $identifier
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 */
+	protected function clearSelectOptionsCache($identifier = NULL) {
+		/** @var CacheManager $cacheManager */
+		$cacheManager = GeneralUtility::makeInstance(CacheManager::class);
+		if ($identifier !== NULL) {
+			$cacheManager->getCache('lfeditor_select_options_cache')->set($identifier, NULL);
+		} else {
+			$cacheManager->getCache('lfeditor_select_options_cache')->flush();
+		}
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/AddConstantController.php

@@ -0,0 +1,176 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Mvc\Exception\UnsupportedRequestTypeException;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * AddConstant controller. It contains extbase actions for AddConstant page.
+ */
+class AddConstantController extends AbstractBackendController {
+	/**
+	 * Opens addConstant view.
+	 * It is called in 2 cases:
+	 * - on selection of addConstant option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 */
+	public function addConstantAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'AddConstant');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->prepareAddConstantViewMainSectionContent();
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in addConstant view.
+	 * It is called on change of selection of any select menu in addConstant view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction($extensionSelection = NULL, $languageFileSelection = NULL, $extKey = ''): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('addConstant');
+			return NULL;
+		} else {
+			return $this->redirect('addConstant');
+		}
+	}
+
+	/**
+	 * Saves the changes made in main section of addConstant view.
+	 *
+	 * @param string $nameOfConstant
+	 * @param array $addConstTextArea
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function addConstantSaveAction($nameOfConstant, array $addConstTextArea): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			if (empty($nameOfConstant)) {
+				throw new LFException('failure.select.noConstDefined');
+			}
+			$extConfig = $this->configurationService->getExtConfig();
+
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+
+			$langData = $this->configurationService->getFileObj()->getLocalLangData();
+
+			$constExists = !empty($langData['default'][$nameOfConstant])
+				|| !empty($langData[$extConfig['defaultLanguage']][$nameOfConstant]);
+			if ($constExists) {
+				throw new LFException('failure.langfile.constExists');
+			}
+
+			$newConstLanguages = [];
+			foreach ($addConstTextArea as $lang => $value) {
+				$newConstLanguages[$lang][$nameOfConstant] = $value;
+			}
+
+			$this->configurationService->execWrite($newConstLanguages);
+			$this->session->setDataByKey('constantSelection', $nameOfConstant);
+
+			$this->addFlashMessage(
+				LocalizationUtility::translate('lang.file.write.success', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('addConstant');
+			return NULL;
+		} else {
+			return $this->redirect('addConstant');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('addConstant');
+			return NULL;
+		} else {
+			return $this->redirect('addConstant');
+		}
+	}
+
+	/**
+	 * Prepares main section content of addConstant view.
+	 *
+	 * @throws LFException
+	 * @return void
+	 */
+	protected function prepareAddConstantViewMainSectionContent() {
+		$extConfig = $this->configurationService->getExtConfig();
+		$langArray = $this->configurationService->getLangArray($this->backendUser);
+
+		$this->view->assign('languages', $langArray);
+		$this->view->assign('numTextAreaRows', $extConfig['numTextAreaRows']);
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/DeleteConstantController.php

@@ -0,0 +1,189 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use SGalinski\Lfeditor\Service\FileOverrideService;
+use SGalinski\Lfeditor\Utility\Functions;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Mvc\Exception\UnsupportedRequestTypeException;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * DeleteConstant controller. It contains extbase actions for DeleteConstant page.
+ */
+class DeleteConstantController extends AbstractBackendController {
+	/**
+	 * Opens deleteConstant view.
+	 * It is called in 2 cases:
+	 * - on selection of deleteConstant option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 */
+	public function deleteConstantAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'DeleteConstant');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+			$fileObject = $this->configurationService->getFileObj();
+			if ($this->session->getDataByKey('editingMode') === 'override') {
+				/** @var FileOverrideService $overrideFileObject */
+				$overrideFileObject = $fileObject;
+				$overrideFileObject->deleteDuplicates();
+			}
+
+			$langData = $fileObject->getLocalLangData();
+			$constantOptions = $this->configurationService->menuConstList(
+				$langData,
+				LocalizationUtility::translate('select.nothing', 'lfeditor')
+			);
+			$this->assignViewWidthMenuVariables('constant', $constantOptions);
+			$this->prepareDeleteConstantViewMainSectionContent();
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in deleteConstant view.
+	 * It is called on change of selection of any select menu in deleteConstant view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $constantSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction(
+		$extensionSelection = NULL,
+		$languageFileSelection = NULL,
+		$constantSelection = NULL,
+		$extKey = ''
+	): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			NULL,
+			$constantSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('deleteConstant');
+			return NULL;
+		} else {
+			return $this->redirect('deleteConstant');
+		}
+	}
+
+	/**
+	 * Saves the changes made in main section of deleteConstant view.
+	 *
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function deleteConstantSaveAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$constantSelection = $this->session->getDataByKey('constantSelection');
+			$langArray = Functions::buildLangArray();
+
+			// build modArray
+			$newLang = [];
+			foreach ($langArray as $lang) {
+				$newLang[$lang][$constantSelection] = '';
+			}
+
+			$this->configurationService->execWrite($newLang, [], TRUE);
+
+			$this->addFlashMessage(
+				LocalizationUtility::translate('lang.file.write.success', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('deleteConstant');
+			return NULL;
+		} else {
+			return $this->redirect('deleteConstant');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('deleteConstant');
+			return NULL;
+		} else {
+			return $this->redirect('deleteConstant');
+		}
+	}
+
+	/**
+	 * Prepares main section content of deleteConstant view.
+	 *
+	 * @throws LFException
+	 * @return void
+	 */
+	protected function prepareDeleteConstantViewMainSectionContent() {
+		$constantSelection = $this->session->getDataByKey('constantSelection');
+		if (empty($constantSelection) || $constantSelection == '###default###') {
+			throw new LFException('failure.select.noConst', 1);
+		}
+
+		$this->view->assign('constantSelection', $constantSelection);
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/EditConstantController.php

@@ -0,0 +1,204 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * EditConstant controller. It contains extbase actions for EditConstant page.
+ */
+class EditConstantController extends AbstractBackendController {
+	/**
+	 * Opens editConstant view.
+	 * It is called in 2 cases:
+	 * - on selection of editConstant option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 */
+	public function editConstantAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'EditConstant');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+
+			$langData = $this->configurationService->getFileObj()->getLocalLangData();
+			$constantOptions = $this->configurationService->menuConstList(
+				$langData,
+				LocalizationUtility::translate('select.nothing', 'lfeditor')
+			);
+			$this->assignViewWidthMenuVariables('constant', $constantOptions);
+
+			$this->prepareEditConstantViewMainSectionContent($langData);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		$this->commonViewRenderingActionSettings();
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in editConstant view.
+	 * It is called on change of selection of any select menu in editConstant view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $constantSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction(
+		$extensionSelection = NULL,
+		$languageFileSelection = NULL,
+		$constantSelection = NULL,
+		$extKey = ''
+	): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			NULL,
+			$constantSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editConstant');
+			return NULL;
+		} else {
+			return $this->redirect('editConstant');
+		}
+	}
+
+	/**
+	 * Saves the changes made in main section of editConstant view.
+	 *
+	 * @param array $editConstTextArea
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function editConstantSaveAction(array $editConstTextArea): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->configurationService->execWrite($editConstTextArea);
+
+			$this->addFlashMessage(
+				LocalizationUtility::translate('lang.file.write.success', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editConstant');
+			return NULL;
+		} else {
+			return $this->redirect('editConstant');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editConstant');
+			return NULL;
+		} else {
+			return $this->redirect('editConstant');
+		}
+	}
+
+	/**
+	 * Prepares main section content of editConstant view.
+	 *
+	 * @param array $langData
+	 * @throws LFException
+	 * @return void
+	 */
+	protected function prepareEditConstantViewMainSectionContent(array $langData = NULL) {
+		$extConfig = $this->configurationService->getExtConfig();
+		$langArray = $this->configurationService->getLangArray($this->backendUser);
+
+		$constantSelection = $this->session->getDataByKey('constantSelection');
+		if (empty($constantSelection) || $constantSelection == '###default###') {
+			throw new LFException('failure.select.noConst', 1);
+		}
+
+		$languages = [];
+		foreach ($langArray as $lang) {
+			if (array_key_exists($lang, $langData) && array_key_exists($constantSelection, $langData[$lang])) {
+				$languages[$lang] = $langData[$lang][$constantSelection];
+			} else {
+				$languages[$lang] = '';
+			}
+		}
+
+		$this->view->assign('constantSelection', $constantSelection);
+		$this->view->assign('languages', $languages);
+		$this->view->assign('numTextAreaRows', $extConfig['numTextAreaRows']);
+		$this->view->assign('defaultLanguage', $extConfig['defaultLanguage']);
+	}
+
+	/**
+	 * Sets chosen constant and redirects to editConstant view.
+	 *
+	 * @param string $constantKey
+	 * @return void
+	 */
+	protected function prepareEditConstantAction($constantKey) {
+		$this->session->setDataByKey('constantSelection', $constantKey);
+
+		$this->redirect('editConstant', 'EditConstant');
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/EditFileController.php

@@ -0,0 +1,365 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * EditFile controller. It contains extbase actions of EditFile page.
+ */
+class EditFileController extends AbstractBackendController {
+	/**
+	 * Opens editFile view.
+	 * It is called in 2 cases:
+	 * - on selection of editFile option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 * @param integer $buttonType :
+	 *                    -1 - cancel,
+	 *                     0 - no button clicked,
+	 *                     1 - back,
+	 *                     2 - next,
+	 *                     3 - save.
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 */
+	public function editFileAction(int $buttonType = 0): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'EditFile');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+			$langData = $this->configurationService->getFileObj()->getLocalLangData();
+
+			$languageOptions = $this->configurationService->menuLangList($langData, '', $this->backendUser);
+			$this->assignViewWidthMenuVariables('language', $languageOptions);
+
+			$referenceLanguageOptions = $this->configurationService->menuLangList(
+				$langData,
+				LocalizationUtility::translate('select.nothing', 'lfeditor'),
+				$this->backendUser
+			);
+			$this->assignViewWidthMenuVariables('referenceLanguage', $referenceLanguageOptions);
+
+			$bottomReferenceLanguageOptions = $this->configurationService->menuLangList(
+				$langData,
+				'',
+				$this->backendUser,
+				TRUE
+			);
+			$this->assignViewWidthMenuVariables('bottomReferenceLanguage', $bottomReferenceLanguageOptions);
+
+			$constantTypeOptions = $this->getConstantTypeOptions();
+			$this->assignViewWidthMenuVariables('constantType', $constantTypeOptions);
+
+			$extConfig = $this->configurationService->getExtConfig();
+			$this->assignViewWidthMenuVariables('numSiteConsts', $extConfig['numSiteConstsOptions']);
+
+			$this->prepareEditFileViewMainSectionContent($langData, $buttonType);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in editFile view.
+	 * It is called on change of selection of any select menu in editFile view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $languageSelection
+	 * @param string $referenceLanguageSelection
+	 * @param string $constantTypeSelection
+	 * @param string $bottomReferenceLanguageSelection
+	 * @param string $numSiteConstsSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction(
+		$extensionSelection = NULL,
+		$languageFileSelection = NULL,
+		$languageSelection = NULL,
+		$referenceLanguageSelection = NULL,
+		$constantTypeSelection = NULL,
+		$bottomReferenceLanguageSelection = NULL,
+		$numSiteConstsSelection = NULL,
+		$extKey = ''
+	): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			$referenceLanguageSelection,
+			NULL,
+			$languageSelection,
+			$constantTypeSelection,
+			$bottomReferenceLanguageSelection,
+			$numSiteConstsSelection,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editFile', NULL, NULL, ['buttonType' => 0]);
+			return NULL;
+		} else {
+			return $this->redirect('editFile', NULL, NULL, ['buttonType' => 0]);
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editFile', NULL, NULL, ['buttonType' => 0]);
+			return NULL;
+		} else {
+			return $this->redirect('editFile', NULL, NULL, ['buttonType' => 0]);
+		}
+	}
+
+	/**
+	 * Prepares main section content of editFile view.
+	 * Structure of the content:
+	 * $constValues[$constant]['edit'],
+	 * $constValues[$constant]['pattern'],
+	 * $constValues[$constant][$extConfig['defaultLanguage']].
+	 *
+	 * @param array $langData
+	 * @param integer $buttonType :
+	 *                    -1 - cancel,
+	 *                     0 - no button clicked,
+	 *                     1 - back,
+	 *                     2 - next,
+	 *                     3 - save.
+	 * @throws LFException
+	 * @return void
+	 */
+	protected function prepareEditFileViewMainSectionContent(array $langData, int $buttonType) {
+		$extConfig = $this->configurationService->getExtConfig();
+		$numConstantsPerPage = $this->session->getDataByKey('numSiteConstsSelection');
+
+		$langList = $this->session->getDataByKey('languageSelection');
+		$patternList = $this->session->getDataByKey('referenceLanguageSelection');
+		$constTypeList = $this->session->getDataByKey('constantTypeSelection');
+		$parallelEdit = $patternList !== '###default###' && $patternList != $langList;
+
+		$langEdit = (array_key_exists($langList, $langData) && is_array($langData[$langList])) ? $langData[$langList] : [];
+		$langPattern = (array_key_exists($patternList, $langData) && is_array($langData[$patternList])) ? $langData[$patternList] : [];
+		$bottomReferenceLanguageSelection = $this->session->getDataByKey('bottomReferenceLanguageSelection');
+		$bottomReferenceLanguage = is_array($langData[$bottomReferenceLanguageSelection])
+			? $langData[$bottomReferenceLanguageSelection] : [];
+		if (empty($bottomReferenceLanguage)) {
+			$bottomReferenceLanguage = is_array($langData['default']) ? $langData['default'] : [];
+		}
+
+		$langDataSessionContinued = $buttonType !== 3;
+		if ($buttonType === 0) {
+			$this->session->setDataByKey('sessionLangDataConstantsIterator', 0);
+			$this->session->setDataByKey('numberLastPageConstants', 0);
+		}
+		$sessionLangDataConstantsIterator = $this->session->getDataByKey('sessionLangDataConstantsIterator');
+		$numberLastPageConstants = $this->session->getDataByKey('numberLastPageConstants');
+
+		// new translation
+		if (!$langDataSessionContinued || $buttonType <= 0) {
+			// adjust number of session constants
+			if ($constTypeList === 'untranslated' || $constTypeList === 'translated' ||
+				$constTypeList === 'unknown' || $buttonType <= 0
+			) {
+				$sessionLangDataConstantsIterator = 0;
+			} elseif (!$langDataSessionContinued) { // session written to file
+				$sessionLangDataConstantsIterator -= $numberLastPageConstants;
+			}
+
+			// delete old data in session
+			$this->session->setDataByKey('langfileEditNewLangData', NULL);
+			$this->session->setDataByKey('langfileEditConstantsList', NULL);
+
+			// get language data
+			if ($constTypeList === 'untranslated') {
+				$myLangData = array_diff_key($bottomReferenceLanguage, $langEdit);
+			} elseif ($constTypeList === 'unknown') {
+				$myLangData = array_diff_key($langEdit, $bottomReferenceLanguage);
+			} elseif ($constTypeList === 'translated') {
+				$myLangData = array_intersect_key($bottomReferenceLanguage, $langEdit);
+			} else {
+				$myLangData = $bottomReferenceLanguage;
+			}
+			$this->session->setDataByKey('langfileEditConstantsList', array_keys($myLangData));
+		} elseif ($buttonType === 1) { // back button
+			$sessionLangDataConstantsIterator -= ($numConstantsPerPage + $numberLastPageConstants);
+		}
+
+		// get language constants
+		$langData = $this->session->getDataByKey('langfileEditConstantsList');
+		$numConsts = is_countable($langData) ? count($langData) : 0;
+		if (!(is_countable($langData) ? count($langData) : 0)) {
+			throw new LFException('failure.select.emptyLangDataArray', 1);
+		}
+		$langfileEditNewLangData = $this->session->getDataByKey('langfileEditNewLangData');
+		if ($langfileEditNewLangData === '') {
+			$langfileEditNewLangData = [];
+		}
+
+		// prepare constant list for this page
+		$numberLastPageConstants = 0;
+		$constValues = [];
+		do {
+			// check number of session constants
+			if ($sessionLangDataConstantsIterator >= $numConsts) {
+				break;
+			}
+			++$numberLastPageConstants;
+
+			// set constant value (maybe already changed in this session)
+			$constant = $langData[$sessionLangDataConstantsIterator];
+			$editLangVal = $langEdit[$constant] ?? '';
+			if (!isset($langfileEditNewLangData[$langList][$constant])) {
+				$langfileEditNewLangData[$langList][$constant] = $editLangVal;
+			} else {
+				$editLangVal = $langfileEditNewLangData[$langList][$constant];
+			}
+
+			// set constant value (maybe already changed in this session)
+			$editPatternVal = $langPattern[$constant] ?? '';
+			if (!isset($langfileEditNewLangData[$patternList][$constant])) {
+				$langfileEditNewLangData[$patternList][$constant] = $editPatternVal;
+			} else {
+				$editPatternVal =
+					$langfileEditNewLangData[$patternList][$constant];
+			}
+
+			// save information about the constant
+			$constValues[$constant]['edit'] = $editLangVal;
+			$constValues[$constant]['pattern'] = $editPatternVal;
+			$constValues[$constant]['default'] = $bottomReferenceLanguage[$constant];
+		} while (++$sessionLangDataConstantsIterator % $numConstantsPerPage);
+
+		$this->session->setDataByKey('langfileEditNewLangData', $langfileEditNewLangData);
+		$this->session->setDataByKey('sessionLangDataConstantsIterator', $sessionLangDataConstantsIterator);
+		$this->session->setDataByKey('numberLastPageConstants', $numberLastPageConstants);
+
+		$this->view->assign('numTextAreaRows', $extConfig['numTextAreaRows']);
+		$this->view->assign('defaultLanguage', $extConfig['defaultLanguage']);
+		$this->view->assign('parallelEdit', $parallelEdit);
+		$this->view->assign('displayBackButton', $sessionLangDataConstantsIterator > $numConstantsPerPage);
+		$this->view->assign('displayNextButton', $sessionLangDataConstantsIterator < $numConsts);
+
+		$this->view->assign('constValues', $constValues);
+		$this->view->assign('curConsts', $sessionLangDataConstantsIterator);
+		$this->view->assign('totalConsts', $numConsts);
+		$this->view->assign('numSiteConstsSelection', $numConstantsPerPage);
+	}
+
+	/**
+	 * Used for the constant type selector
+	 *
+	 * @return array
+	 */
+	private function getConstantTypeOptions(): array {
+		$constantTypeOptions = [];
+		$constantTypeOptions['all'] = LocalizationUtility::translate('const.type.all', 'lfeditor');
+		$constantTypeOptions['translated'] = LocalizationUtility::translate('const.type.translated', 'lfeditor');
+		$constantTypeOptions['unknown'] = LocalizationUtility::translate('const.type.unknown', 'lfeditor');
+		$constantTypeOptions['untranslated'] = LocalizationUtility::translate('const.type.untranslated', 'lfeditor');
+		return $constantTypeOptions;
+	}
+
+	/**
+	 * Saves the changes made in main section of editFile view.
+	 *
+	 * @param integer $buttonType
+	 * @param array $editFileTextArea editFileTextArea[{languageSelection}][{constKey}]
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function editFileSaveAction(int $buttonType, array $editFileTextArea): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$languageSelection = $this->session->getDataByKey('languageSelection');
+			$referenceLanguageSelection = $this->session->getDataByKey('referenceLanguageSelection');
+			$langDataSessionContinued = $buttonType !== 3;
+
+			$langfileEditNewLangData = $this->session->getDataByKey('langfileEditNewLangData');
+			$langfileEditNewLangData[$languageSelection] =
+				array_merge(
+					$langfileEditNewLangData[$languageSelection],
+					$editFileTextArea[$languageSelection]
+				);
+
+			// parallel edit mode?
+			if ($referenceLanguageSelection !== '###default###' && $referenceLanguageSelection != $languageSelection) {
+				$langfileEditNewLangData[$referenceLanguageSelection] =
+					array_merge(
+						$langfileEditNewLangData[$referenceLanguageSelection],
+						$editFileTextArea[$referenceLanguageSelection] ?? []
+					);
+			}
+			$this->session->setDataByKey('langfileEditNewLangData', $langfileEditNewLangData);
+
+			// write if no session continued
+			if (!$langDataSessionContinued) {
+				// Making array of languages that were changed, so only that language files will be edited.
+				$editedLanguages = [$languageSelection];
+				if ($languageSelection !== $referenceLanguageSelection) {
+					$editedLanguages[] = $referenceLanguageSelection;
+				}
+
+				$this->configurationService->execWrite($langfileEditNewLangData, [], FALSE, $editedLanguages);
+				$this->addFlashMessage(
+					LocalizationUtility::translate('lang.file.write.success', 'lfeditor'),
+					'',
+					$severity = AbstractMessage::OK,
+					$storeInSession = TRUE
+				);
+			}
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editFile', NULL, NULL, ['buttonType' => $buttonType]);
+			return NULL;
+		} else {
+			return $this->redirect('editFile', NULL, NULL, ['buttonType' => $buttonType]);
+		}
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/GeneralController.php

@@ -0,0 +1,302 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use SGalinski\Lfeditor\Utility\Functions;
+use SGalinski\Lfeditor\Utility\SgLib;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Mvc\Exception\UnsupportedRequestTypeException;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * General controller. It contains extbase actions for general page.
+ */
+class GeneralController extends AbstractBackendController {
+	/** Code for normal split operation */
+	public const NORMAL_SPLIT = 1;
+
+	/** Code for merge operation */
+	public const MERGE = 2;
+
+	/**
+	 * Renders last-opened page. This action ai called upon opening LFEditor.
+	 *
+	 * @param bool $doStateRedirect
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function indexAction($doStateRedirect = TRUE): ?\Psr\Http\Message\ResponseInterface {
+		if ($doStateRedirect) {
+			$this->redirectToLastCalledControllerActionPair();
+		}
+
+		$this->resetLastCalledControllerActionPair();
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('general', 'General');
+			return NULL;
+		} else {
+			return $this->redirect('general', 'General');
+		}
+	}
+
+	/**
+	 * Opens general view.
+	 * It is called in 2 cases:
+	 * - on selection of general option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 */
+	public function generalAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'General');
+
+			$this->prepareExtensionAndLangFileOptions();
+			if (!$this->session->getDataByKey('languageFileSelection')) {
+				throw new LFException('failure.select.noLangfile', 1);
+			}
+			$this->prepareGeneralViewMainSectionContent();
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in general view.
+	 * It is called on change of selection of any select menu in general view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 *
+	 */
+	public function changeSelectionAction($extensionSelection = NULL, $languageFileSelection = NULL, $extKey = ''): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('general');
+			return NULL;
+		} else {
+			return $this->redirect('general');
+		}
+	}
+
+	/**
+	 * Saves the changes made in main section of general view.
+	 *
+	 * @param string $authorName
+	 * @param string $authorEmail
+	 * @param string $metaDescription
+	 * @param string $transformFile
+	 * @param integer $splitFile
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function generalSaveAction(
+		$authorName = NULL,
+		$authorEmail = NULL,
+		$metaDescription = NULL,
+		$transformFile = NULL,
+		$splitFile = NULL
+	): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$metaArray = [
+				'authorName' => $authorName,
+				'authorEmail' => $authorEmail,
+				'description' => $metaDescription
+			];
+			$this->configurationService->execWrite([], $metaArray);
+
+			// split or merge
+			if ($transformFile === 'xlf') {
+				$splitFile = self::NORMAL_SPLIT;
+			}
+			if (($splitFile == self::NORMAL_SPLIT || $splitFile == self::MERGE)) {
+				$langModes = [];
+				// set vars
+				if ($splitFile != self::NORMAL_SPLIT && $splitFile != self::MERGE) {
+					$splitFile = 0;
+				}
+				$langKeys = Functions::buildLangArray();
+
+				// generate langModes
+				foreach ($langKeys as $langKey) {
+					if (!isset($langModes[$langKey])) {
+						$langModes[$langKey] = $splitFile;
+					}
+				}
+
+				// exec split or merge
+				$this->configurationService->execSplitFile($langModes);
+				// reinitialize file object
+				$this->configurationService->initFileObject(
+					$this->session->getDataByKey('languageFileSelection'),
+					$this->session->getDataByKey('extensionSelection')
+				);
+			}
+
+			if (!empty($transformFile)
+				&& $this->configurationService->getFileObj()->getVar('fileType') != $transformFile
+			) {
+				$newFile = SgLib::setFileExtension(
+					$transformFile,
+					$this->configurationService->getFileObj()->getVar('relFile')
+				);
+				$this->configurationService->execTransform($transformFile, $newFile);
+				$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+			}
+
+			$this->addFlashMessage(
+				LocalizationUtility::translate('lang.file.write.success', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('general');
+			return NULL;
+		} else {
+			return $this->redirect('general');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('general');
+			return NULL;
+		} else {
+			return $this->redirect('general');
+		}
+	}
+
+	/**
+	 * Prepares main section content of general view.
+	 *
+	 * @return void
+	 * @throws LFException
+	 */
+	protected function prepareGeneralViewMainSectionContent() {
+		$this->configurationService->initFileObject(
+			$this->session->getDataByKey('languageFileSelection'),
+			$this->session->getDataByKey('extensionSelection')
+		);
+		$extConfig = $this->configurationService->getExtConfig();
+		$referenceLanguageSelection = $extConfig['defaultLanguage'];
+		$langArray = $this->configurationService->getLangArray($this->backendUser);
+		$infoArray = Functions::genGeneralInfoArray(
+			$referenceLanguageSelection,
+			$langArray,
+			$this->configurationService->getFileObj()
+		);
+		$description = $infoArray['default']['meta']['description'] ?? '';
+		$langFileExtension = $this->configurationService->getFileObj()->getVar('fileType');
+		$preselectMerge = $this->isOriginSameForAllLanguages($infoArray);
+
+		$this->view->assign('infos', $infoArray);
+		$this->view->assign('refLangNumTranslated', $infoArray[$referenceLanguageSelection]['numTranslated']);
+		$this->view->assign('numTextAreaRows', $extConfig['numTextAreaRows']);
+		$this->view->assign('metaDescription', $description);
+		$this->view->assign('langFileExtension', $langFileExtension);
+		$this->view->assign('preselectMerge', $preselectMerge);
+	}
+
+	/**
+	 * Prepares parameters for redirection to viewTreeAction.
+	 *
+	 * @param string $language
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function goToEditFileAction($language): ?\Psr\Http\Message\ResponseInterface {
+		$this->session->setDataByKey('languageSelection', $language);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('editFile', 'EditFile');
+			return NULL;
+		} else {
+			return $this->redirect('editFile', 'EditFile');
+		}
+	}
+
+	/**
+	 * Switches between override mode and normal mode.
+	 *
+	 * @param string $editingMode 'extension', 'l10n', 'override'.
+	 * @return void
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function switchEditingModeAction($editingMode = 'extension') {
+		$this->session->setDataByKey('editingMode', $editingMode);
+		$this->indexAction();
+	}
+
+	/**
+	 * Checks do all language translations originate from same file.
+	 *
+	 * @param array $infoArray
+	 * @return bool
+	 */
+	private function isOriginSameForAllLanguages(array $infoArray) {
+		foreach ($infoArray as $langInfo) {
+			if ($infoArray['default']['origin'] !== $langInfo['origin']) {
+				return FALSE;
+			}
+		}
+		return TRUE;
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/ManageBackupsController.php

@@ -0,0 +1,500 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use SGalinski\Lfeditor\Utility\Functions;
+use SGalinski\Lfeditor\Utility\SgLib;
+use SGalinski\Lfeditor\Utility\Typo3Lib;
+use TYPO3\CMS\Core\Core\Environment;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * ManageBackups controller. It contains extbase actions for ManageBackups page.
+ */
+class ManageBackupsController extends AbstractBackendController {
+	/**
+	 * A constant which is used in backup feature to indicate that
+	 * language constant is added after backup file was made.
+	 */
+	public const LANG_CONST_ADDED = 2;
+
+	/**
+	 * A constant which is used in backup feature to indicate that
+	 * language constant is deleted after backup file was made.
+	 */
+	public const LANG_CONST_DELETED = 1;
+
+	/**
+	 * A constant which is used in backup feature to indicate that
+	 * language constant isn't deleted nor added after backup file was made. It was just changed.
+	 */
+	public const LANG_CONST_NORMAL = 0;
+
+	/**
+	 * Opens manageBackups view.
+	 * It is called in 2 cases:
+	 * - on selection of manageBackups option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 * @param string $fileName
+	 * @param string $langFile language file which was altered.
+	 * @param bool $showDiff
+	 * @throws \Exception
+	 */
+	public function manageBackupsAction($fileName = '', $langFile = '', $showDiff = FALSE): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'ManageBackups');
+
+			$extensionOptions = $this->configurationService->menuExtList();
+			$this->assignViewWidthMenuVariables('extension', $extensionOptions);
+
+			$this->initializeBackupObject($langFile);
+			$this->prepareManageBackupsViewMainSectionContent();
+			if ($showDiff) {
+				$this->generateDiffContent($fileName);
+			}
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in manageBackups view.
+	 * It is called on change of selection of any select menu in searchConstant view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $extKey
+	 */
+	public function changeSelectionAction($extensionSelection = NULL, $extKey = ''): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('manageBackups');
+			return NULL;
+		} else {
+			return $this->redirect('manageBackups');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('manageBackups');
+			return NULL;
+		} else {
+			return $this->redirect('manageBackups');
+		}
+	}
+
+	/**
+	 * Prepares main section content of manageBackupsConstant view.
+	 *
+	 * @throws LFException
+	 */
+	protected function prepareManageBackupsViewMainSectionContent() {
+		$backups = $this->makeBackupsList();
+		if (empty($backups)) {
+			$this->addFlashMessage(
+				LocalizationUtility::translate('failure.backup.noFiles', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::NOTICE,
+				$storeInSession = TRUE
+			);
+			return;
+		}
+		$recoverLabelThead = strtoupper(
+			substr(LocalizationUtility::translate('function.backupMgr.recover', 'lfeditor'), 0, 1)
+		);
+		$differenceLabelThead = strtoupper(
+			substr(LocalizationUtility::translate('function.backupMgr.diff.diff', 'lfeditor'), 0, 1)
+		);
+
+		$this->view->assign('backups', $backups);
+		$this->view->assign('recoverLabelThead', $recoverLabelThead);
+		$this->view->assign('differenceLabelThead', $differenceLabelThead);
+	}
+
+	/**
+	 * Makes list of backups for use in fluid page.
+	 *
+	 * @return array
+	 */
+	protected function makeBackupsList() {
+		$backups = [];
+		$metaArray = $this->backupService->getBackupObj()->getMetaInfos(2);
+		if (is_array($metaArray)) {
+			$keys = array_keys($metaArray);
+			foreach ($keys as $langFile) {
+				foreach ($metaArray[$langFile] as $fileName => $informations) {
+					$backup = [];
+
+					// get path to filename
+					$backupPath = $informations['pathBackup'];
+					$pathSite = Environment::getPublicPath() . '/';
+
+					$file = Typo3Lib::fixFilePath($pathSite . '/' . $backupPath . '/' . $fileName);
+					$origFile = Typo3Lib::fixFilePath(
+						$this->session->getDataByKey('extensionSelection') . '/' . $langFile
+					);
+
+					// check state
+					if (!is_file($file)) {
+						$backup['state'] = 'function.backupMgr.missing';
+					} elseif (!is_file($origFile)) {
+						$backup['state'] = 'lang.file.missing';
+					} else {
+						$backup['state'] = 'function.backupMgr.ok';
+					}
+
+					$backup['date'] = date('Y-m-d H:i:s', $informations['createdAt']);
+					$backup['langFile'] = $langFile;
+					$backup['fileName'] = $fileName;
+					$backups[] = $backup;
+				}
+			}
+		}
+		return $backups;
+	}
+
+	/**
+	 * Deletes all backups.
+	 *
+	 */
+	public function deleteAllBackupAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->initializeBackupObject();
+			$delFiles = [];
+			$metaArray = $this->backupService->getBackupObj()->getMetaInfos(2);
+			foreach ($metaArray as $langFile => $metaPiece) {
+				$files = array_keys($metaPiece);
+				foreach ($files as $filename) {
+					$delFiles[$filename] = $langFile;
+				}
+			}
+			$this->backupService->execBackupDelete($delFiles);
+			$this->addFlashMessage(
+				LocalizationUtility::translate('function.backupMgr.success.deleteAll', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('manageBackups');
+			return NULL;
+		} else {
+			return $this->redirect('manageBackups');
+		}
+	}
+
+	/**
+	 * Deletes backup.
+	 *
+	 * @param string $fileName
+	 * @param string $langFile
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function deleteBackupAction($fileName, $langFile): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->initializeBackupObject($langFile);
+			$delFiles = [];
+			$delFiles[$fileName] = '';
+			$this->backupService->execBackupDelete($delFiles);
+			$this->addFlashMessage(
+				LocalizationUtility::translate('function.backupMgr.success.delete', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->redirect('manageBackups');
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('manageBackups');
+			return NULL;
+		} else {
+			return $this->redirect('manageBackups');
+		}
+	}
+
+	/**
+	 * Uses backup to recover changes.
+	 *
+	 * @param string $fileName
+	 * @param string $langFile
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function recoverBackupAction($fileName, $langFile): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->initializeBackupObject($langFile);
+			// set backup file
+			$metaArray = $this->backupService->getBackupObj()->getMetaInfos(3);
+			$pathSite = Environment::getPublicPath() . '/';
+
+			$information = [
+				'absPath' => $pathSite . $metaArray[$fileName]['pathBackup'],
+				'relFile' => $fileName,
+			];
+			$this->backupService->getBackupObj()->setVar($information);
+			$this->backupService->getBackupObj()->readFile();
+			// read original file
+			$this->configurationService->initFileObject(
+				$this->backupService->getBackupObj()->getVar('langFile'),
+				Typo3Lib::fixFilePath($pathSite . '/' . $this->backupService->getBackupObj()->getVar('extPath'))
+			);
+			// restore
+			$this->backupService->execBackupRestore();
+			$this->addFlashMessage(
+				LocalizationUtility::translate('function.backupMgr.success.restore', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('manageBackups');
+			return NULL;
+		} else {
+			return $this->redirect('manageBackups');
+		}
+	}
+
+	/**
+	 * Shows differences between backup and original.
+	 *
+	 * @param string $fileName
+	 * @param string $langFile
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function showDifferenceBackupAction($fileName, $langFile): ?\Psr\Http\Message\ResponseInterface {
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect(
+				'manageBackups',
+				NULL,
+				NULL,
+				['fileName' => $fileName, 'langFile' => $langFile, 'showDiff' => TRUE]
+			);
+			return NULL;
+		} else {
+			return $this->redirect(
+				'manageBackups',
+				NULL,
+				NULL,
+				['fileName' => $fileName, 'langFile' => $langFile, 'showDiff' => TRUE]
+			);
+		}
+	}
+
+	/**
+	 * Initializes backup object.
+	 *
+	 * @param string $langFile
+	 * @throws LFException
+	 * @throws \Exception
+	 * @return void
+	 */
+	protected function initializeBackupObject($langFile = '') {
+		$pathSite = Environment::getPublicPath() . '/';
+		$information = [
+			'extPath' => SgLib::trimPath($pathSite, $this->session->getDataByKey('extensionSelection')),
+			'langFile' => $langFile,
+		];
+		$this->backupService->initBackupObject('base', $information);
+	}
+
+	/**
+	 * Generates content which illustrates differences between backup and current state.
+	 *
+	 * @param string $fileName
+	 * @return void
+	 */
+	protected function generateDiffContent($fileName) {
+		$localLangDiff = NULL;
+		$metaDiff = NULL;
+		$pathSite = Environment::getPublicPath() . '/';
+		// set backup file
+		$metaArray = $this->backupService->getBackupObj()->getMetaInfos(3);
+		$informations = [
+			'absPath' => Typo3Lib::fixFilePath(
+				$pathSite . '/' .
+				$metaArray[$fileName]['pathBackup']
+			),
+			'relFile' => $fileName,
+		];
+		$this->backupService->getBackupObj()->setVar($informations);
+
+		// exec diff
+		// read original file
+		$this->configurationService->initFileObject(
+			$this->backupService->getBackupObj()->getVar('langFile'),
+			Typo3Lib::fixFilePath($pathSite . '/' . $this->backupService->getBackupObj()->getVar('extPath'))
+		);
+
+		// read backup file
+		$this->backupService->getBackupObj()->readFile();
+
+		// get language data
+		$originalLocalLang = $this->configurationService->getFileObj()->getLocalLangData();
+		$backupLocalLang = $this->backupService->getBackupObj()->getLocalLangData();
+
+		// get meta data
+		$origMeta = $this->configurationService->getFileObj()->getMetaData();
+		$backupMeta = $this->backupService->getBackupObj()->getMetaData();
+
+		SgLib::fixMetaAttributes($origMeta);
+		unset($originalLocalLang['trans-unit']);
+		$localLangDiff = Functions::getBackupDiff(0, $originalLocalLang, $backupLocalLang);
+		$metaDiff = Functions::getMetaDiff(0, $origMeta, $backupMeta);
+
+		// generate diff
+		if (is_countable($localLangDiff) ? count($localLangDiff) : 0) {
+			$this->outputManageBackupsDiff(
+				$localLangDiff,
+				$metaDiff,
+				$originalLocalLang,
+				$backupLocalLang,
+				$this->configurationService->getFileObj()->getOriginLangData(),
+				$this->backupService->getBackupObj()->getOriginLangData(),
+				$origMeta,
+				$backupMeta
+			);
+		}
+	}
+
+	/**
+	 * Generates output of difference between backup and original.
+	 *
+	 * @param array $diff language content (difference between backup and origin)
+	 * @param array $metaDiff meta content (difference between backup and origin)
+	 * @param array $origLang original language content
+	 * @param array $backupLang backup language content
+	 * @param array $origOriginLang original origins of each language
+	 * @param array $backupOriginLang backup origins of each language
+	 * @param array $origMeta original meta content
+	 * @param array $backupMeta backup meta content
+	 * @return void
+	 */
+	protected function outputManageBackupsDiff(
+		$diff,
+		$metaDiff,
+		$origLang,
+		$backupLang,
+		$origOriginLang,
+		$backupOriginLang,
+		$origMeta,
+		$backupMeta
+	) {
+		$differences = [];
+
+		// meta entry
+		if (count($metaDiff)) {
+			$difference = [];
+			$difference['legend'] = LocalizationUtility::translate('function.backupMgr.diff.meta', 'lfeditor');
+			$difference['constants'] = [];
+			foreach ($metaDiff as $label => $value) {
+				$constant = [];
+				$constant['value'] = $value;
+				$constant['label'] = $label;
+				if (!isset($backupMeta[$label])) {
+					$constant['state'] = self::LANG_CONST_ADDED;
+				} elseif (!isset($origMeta[$label])) {
+					$constant['state'] = self::LANG_CONST_DELETED;
+				} else {
+					$constant['state'] = self::LANG_CONST_NORMAL;
+				}
+				$difference['constants'][] = $constant;
+			}
+			$differences[] = $difference;
+		}
+
+		// loop each language entry
+		foreach ($diff as $langKey => $data) {
+			$difference = [];
+			if (!(is_countable($data) ? count($data) : 0) && ($origOriginLang[$langKey] == $backupOriginLang[$langKey])) {
+				continue;
+			}
+			try {
+				$languageFile = Typo3Lib::transTypo3File($backupOriginLang[$langKey], FALSE);
+			} catch (\Exception $e) {
+				$languageFile = $backupOriginLang[$langKey];
+			}
+			$difference['legend'] = $langKey . ' (' . $languageFile . ')';
+			$difference['constants'] = [];
+			foreach ($data as $label => $value) {
+				$constant = [];
+				$constant['value'] = $value;
+				$constant['label'] = $label;
+
+				if (!isset($backupLang[$langKey][$label])) {
+					$constant['state'] = self::LANG_CONST_ADDED;
+				} elseif (!isset($origLang[$langKey][$label])) {
+					$constant['state'] = self::LANG_CONST_DELETED;
+				} else {
+					$constant['state'] = self::LANG_CONST_NORMAL;
+				}
+				$difference['constants'][] = $constant;
+			}
+			$differences[] = $difference;
+		}
+		$this->view->assign('differences', $differences);
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/RenameConstantController.php

@@ -0,0 +1,198 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use SGalinski\Lfeditor\Utility\Functions;
+use TYPO3\CMS\Core\Messaging\AbstractMessage;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * RenameConstant controller. It contains extbase actions for RenameConstant page.
+ */
+class RenameConstantController extends AbstractBackendController {
+	/**
+	 * Opens renameConstant view.
+	 * It is called in 2 cases:
+	 * - on selection of renameConstant option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 */
+	public function renameConstantAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'RenameConstant');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+			$langData = $this->configurationService->getFileObj()->getLocalLangData();
+			$constantOptions = $this->configurationService->menuConstList(
+				$langData,
+				LocalizationUtility::translate('select.nothing', 'lfeditor')
+			);
+			$this->assignViewWidthMenuVariables('constant', $constantOptions);
+			$this->prepareRenameConstantViewMainSectionContent();
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in renameConstant view.
+	 * It is called on change of selection of any select menu in renameConstant view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $constantSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction(
+		$extensionSelection = NULL,
+		$languageFileSelection = NULL,
+		$constantSelection = NULL,
+		$extKey = ''
+	): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			NULL,
+			$constantSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('renameConstant');
+			return NULL;
+		} else {
+			return $this->redirect('renameConstant');
+		}
+	}
+
+	/**
+	 * Saves the changes made in main section of renameConstant view.
+	 *
+	 * @param string $newConstantName
+	 */
+	public function renameConstantSaveAction($newConstantName): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$oldConstantName = $this->session->getDataByKey('constantSelection');
+			$extConfig = $this->configurationService->getExtConfig();
+
+			if ($oldConstantName === $newConstantName) {
+				throw new LFException('failure.langfile.noChange');
+			}
+
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+
+			$langData = $this->configurationService->getFileObj()->getLocalLangData();
+			$constExists = !empty($langData['default'][$newConstantName])
+				|| !empty($langData[$extConfig['defaultLanguage']][$newConstantName]);
+			if ($constExists) {
+				throw new LFException('failure.langfile.constExists');
+			}
+
+			$langArray = Functions::buildLangArray();
+			$newLang = [];
+			foreach ($langArray as $lang) {
+				if (isset($langData[$lang][$oldConstantName])) {
+					$newLang[$lang][$newConstantName] = $langData[$lang][$oldConstantName];
+				}
+				$newLang[$lang][$oldConstantName] = '';
+			}
+
+			$this->configurationService->execWrite($newLang, [], TRUE);
+
+			$this->addFlashMessage(
+				LocalizationUtility::translate('lang.file.write.success', 'lfeditor'),
+				'',
+				$severity = AbstractMessage::OK,
+				$storeInSession = TRUE
+			);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('renameConstant');
+			return NULL;
+		} else {
+			return $this->redirect('renameConstant');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 * @return \Psr\Http\Message\ResponseInterface|null
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('renameConstant');
+			return NULL;
+		} else {
+			return $this->redirect('renameConstant');
+		}
+	}
+
+	/**
+	 * Prepares main section content of deleteConstant view.
+	 *
+	 * @throws LFException
+	 * @return void
+	 */
+	protected function prepareRenameConstantViewMainSectionContent() {
+		$constantSelection = $this->session->getDataByKey('constantSelection');
+		if (empty($constantSelection) || $constantSelection === '###default###') {
+			throw new LFException('failure.select.noConst', 1);
+		}
+
+		$this->view->assign('constantSelection', $constantSelection);
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/SearchConstantController.php

@@ -0,0 +1,182 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use TYPO3\CMS\Extbase\Mvc\Exception\UnsupportedRequestTypeException;
+
+/**
+ * SearchConstant controller. It contains extbase actions for SearchConstant page.
+ */
+class SearchConstantController extends AbstractBackendController {
+	/**
+	 * Opens searchConstant view.
+	 * It is called in 2 cases:
+	 * - on selection of searchConstant option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 * @param bool $searchDone
+	 * @throws \TYPO3\CMS\Core\Cache\Exception\NoSuchCacheException
+	 */
+	public function searchConstantAction($searchDone = FALSE): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'SearchConstant');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->prepareSearchConstantViewMainSectionContent($searchDone);
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in searchConstant view.
+	 * It is called on change of selection of any select menu in searchConstant view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction($extensionSelection = NULL, $languageFileSelection = NULL, $extKey = ''): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('searchConstant');
+			return NULL;
+		} else {
+			return $this->redirect('searchConstant');
+		}
+	}
+
+	/**
+	 * Saves the changes made in main section of searchConstant view.
+	 *
+	 * @param boolean $caseSensitive
+	 * @param string $searchStr
+	 */
+	public function searchConstantSearchAction($caseSensitive, $searchStr): ?\Psr\Http\Message\ResponseInterface {
+		$searchResultArray = [];
+		try {
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+			$langData = $this->configurationService->getFileObj()->getLocalLangData();
+			$viewLanguages = $this->configurationService->getLangArray($this->backendUser);
+
+			$searchOptions = $caseSensitive ? '' : 'i';
+			if (!preg_match('/^\/.*\/.*$/', $searchStr) && !empty($searchStr)) {
+				foreach ($viewLanguages as $langKey) {
+					if (!array_key_exists($langKey, $langData) || !is_array($langData[$langKey])) {
+						continue;
+					}
+					foreach ($langData[$langKey] as $labelKey => $labelValue) {
+						$labelKeyOrValueContainSearchStr = preg_match(
+							'/' . $searchStr . '/' . $searchOptions,
+							$labelKey
+						) || preg_match('/' . $searchStr . '/' . $searchOptions, $labelValue);
+						if ($labelKeyOrValueContainSearchStr) {
+							$searchResultArray[$langKey][$labelKey] = $labelValue;
+						}
+					}
+				}
+				if (!count($searchResultArray)) {
+					throw new LFException('failure.search.noConstants', 1);
+				}
+			} else {
+				throw new LFException('function.const.search.enterSearchStr', 1);
+			}
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->session->setDataByKey('searchResultArray', $searchResultArray);
+		$this->session->setDataByKey('searchString', $searchStr);
+		$this->session->setDataByKey('searchCaseSensitive', $caseSensitive);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('searchConstant', NULL, NULL, ['searchDone' => TRUE]);
+			return NULL;
+		} else {
+			return $this->redirect('searchConstant', NULL, NULL, ['searchDone' => TRUE]);
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('searchConstant', NULL, NULL, ['searchDone' => TRUE]);
+			return NULL;
+		} else {
+			return $this->redirect('searchConstant', NULL, NULL, ['searchDone' => TRUE]);
+		}
+	}
+
+	/**
+	 * Prepares main section content of searchConstant view.
+	 *
+	 * @param bool $searchDone
+	 * @return void
+	 */
+	protected function prepareSearchConstantViewMainSectionContent($searchDone) {
+		$searchResultArray = [];
+		if ($searchDone) {
+			$searchResultArray = $this->session->getDataByKey('searchResultArray');
+		} else {
+			$this->session->setDataByKey('searchResultArray', []);
+		}
+		$searchString = $this->session->getDataByKey('searchString');
+		$searchCaseSensitive = $this->session->getDataByKey('searchCaseSensitive');
+
+		$this->view->assign('searchResultArray', $searchResultArray);
+		$this->view->assign('searchString', $searchString);
+		$this->view->assign('searchCaseSensitive', $searchCaseSensitive);
+	}
+}

typo3conf/ext/lfeditor/Classes/Controller/ViewTreeController.php

@@ -0,0 +1,283 @@
+<?php
+
+namespace SGalinski\Lfeditor\Controller;
+
+/***************************************************************
+ *  Copyright notice
+ *
+ *  (c) sgalinski Internet Services (https://www.sgalinski.de)
+ *
+ *  All rights reserved
+ *
+ *  This script is part of the TYPO3 project. The TYPO3 project is
+ *  free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  The GNU General Public License can be found at
+ *  http://www.gnu.org/copyleft/gpl.html.
+ *
+ *  This script is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  This copyright notice MUST APPEAR in all copies of the script!
+ ***************************************************************/
+
+use SGalinski\Lfeditor\Exceptions\LFException;
+use SGalinski\Lfeditor\Utility\Functions;
+use TYPO3\CMS\Extbase\Mvc\Exception\UnsupportedRequestTypeException;
+use TYPO3\CMS\Extbase\Utility\LocalizationUtility;
+
+/**
+ * ViewTree controller. It contains extbase actions for ViewTree page.
+ */
+class ViewTreeController extends AbstractBackendController {
+	/*********************************************
+	 *  Actions called from viewTree view  *
+	 *********************************************/
+
+	/**
+	 * Opens viewTree view.
+	 * It is called in 2 cases:
+	 * - on selection of viewTree option in main menu,
+	 * - after redirection from action which must not change the view.
+	 *
+	 */
+	public function viewTreeAction(): ?\Psr\Http\Message\ResponseInterface {
+		try {
+			$this->view->assign('controllerName', 'ViewTree');
+
+			$this->prepareExtensionAndLangFileOptions();
+			$this->configurationService->initFileObject(
+				$this->session->getDataByKey('languageFileSelection'),
+				$this->session->getDataByKey('extensionSelection')
+			);
+			$languageOptions = $this->configurationService->menuLangList(
+				$this->configurationService->getFileObj()->getLocalLangData(),
+				'',
+				$this->backendUser
+			);
+			$this->assignViewWidthMenuVariables('language', $languageOptions);
+			$referenceLanguageOptions = $this->configurationService->menuLangList(
+				$this->configurationService->getFileObj()->getLocalLangData(),
+				LocalizationUtility::translate('select.nothing', 'lfeditor'),
+				$this->backendUser
+			);
+			$this->assignViewWidthMenuVariables('referenceLanguage', $referenceLanguageOptions);
+			$this->prepareViewTreeViewMainSectionContent();
+		} catch (LFException $e) {
+			$this->addLFEFlashMessage($e);
+		}
+		$this->commonViewRenderingActionSettings();
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->view->assign('V11', FALSE);
+			return NULL;
+		} else {
+			$this->view->assign('V11', TRUE);
+			return $this->createBackendResponse();
+		}
+	}
+
+	/**
+	 * This action saves in session currently selected options from selection menus in viewTree view.
+	 * It is called on change of selection of any select menu in viewTree view.
+	 *
+	 * @param string $extensionSelection
+	 * @param string $languageFileSelection
+	 * @param string $languageSelection
+	 * @param string $referenceLanguageSelection
+	 * @param string $extKey
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function changeSelectionAction(
+		$extensionSelection = NULL,
+		$languageFileSelection = NULL,
+		$languageSelection = NULL,
+		$referenceLanguageSelection = NULL,
+		$extKey = ''
+	): ?\Psr\Http\Message\ResponseInterface {
+		$this->saveSelectionsInSession(
+			$extensionSelection,
+			$languageFileSelection,
+			$referenceLanguageSelection,
+			NULL,
+			NULL,
+			$languageSelection,
+			NULL,
+			NULL,
+			$extKey
+		);
+
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('viewTree');
+			return NULL;
+		} else {
+			return $this->redirect('viewTree');
+		}
+	}
+
+	/**
+	 * Selects explodeToken.
+	 *
+	 * @param string $explodeToken
+	 * @throws \TYPO3\CMS\Extbase\Mvc\Exception\StopActionException
+	 */
+	public function selectExplodeTokenAction($explodeToken): ?\Psr\Http\Message\ResponseInterface {
+		$this->session->setDataByKey('explodeToken', $explodeToken);
+
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('viewTree');
+			return NULL;
+		} else {
+			return $this->redirect('viewTree');
+		}
+	}
+
+	/**
+	 * Clears extensionAndLangFileOptions cache, and in that way refreshes list of language file options in select box.
+	 *
+	 */
+	public function refreshLanguageFileListAction(): ?\Psr\Http\Message\ResponseInterface {
+		$this->clearSelectOptionsCache('extensionAndLangFileOptions');
+		if (version_compare(\TYPO3\CMS\Core\Utility\VersionNumberUtility::getCurrentTypo3Version(), '11.0.0', '<')) {
+			$this->redirect('viewTree');
+			return NULL;
+		} else {
+			return $this->redirect('viewTree');
+		}
+	}
+
+	/**
+	 * Prepares main section content of viewTree view.
+	 *
+	 */
+	protected function prepareViewTreeViewMainSectionContent(): void {
+		$explodeToken = $this->session->getDataByKey('explodeToken');
+		if ($explodeToken === "") {
+			$explodeToken = '.';
+		}
+
+		$langData = $this->configurationService->getFileObj()->getLocalLangData();
+		$refLangSelection = $this->session->getDataByKey('referenceLanguageSelection');
+		$languageSelection = $this->session->getDataByKey('languageSelection');
+		$tree = Functions::genTreeInfoArray($langData[$languageSelection] ?? [], $langData[$refLangSelection] ?? [], $explodeToken);
+		$extConfig = $this->configurationService->getExtConfig();
+		$treeHide = $extConfig['treeHide'];
+
+		$fluidTree = [];
+		$levelIndex = 0;
+		$this->addLevelElementsToFluidTree($tree, $levelIndex, NULL, $fluidTree, $treeHide);
+
+		$this->view->assign('fluidTree', $fluidTree);
+		$this->view->assign('treeHide', $treeHide);
+		$this->view->assign('explodeToken', $explodeToken);
+	}
+
+	/**
+	 * @var integer Width of margin which is added if a branch is missing.
+	 */
+	protected $marginLeftSpaceUnit = 18;
+
+	/**
+	 * Makes tree structure which contains constants. The structure is optimised for recursive use on fluid pages.
+	 *
+	 * @param array $sourceTree
+	 * @param int $level
+	 * @param string $parentKey
+	 * @param array $fluidTree This structure is used for setting tree-data for use in fluid.
+	 * @param boolean $treeHide Default state of tree (TRUE - hidden, FALSE - opened)
+	 * @throws LFException
+	 * @return void
+	 */
+	protected function addLevelElementsToFluidTree(
+		array $sourceTree,
+		int $level,
+		$parentKey,
+		array &$fluidTree,
+		$treeHide
+	) {
+		if (empty($sourceTree)) {
+			throw new LFException('failure.select.emptyLanguage', 1);
+		}
+		$constKeys = array_keys($sourceTree[$level]);
+		$index = 0;
+		foreach ($sourceTree[$level] as $constKey => $treeNode) {
+			if ($level === 0 || $treeNode['parent'] === $parentKey) {
+				$fluidTreeElem = [];
+				$fluidTreeElem['label'] = $treeNode['name'];
+				$fluidTreeElem['parent'] = $fluidTree; //$treeNode['parent'];//; //
+				$fluidTreeElem['type'] = $treeNode['type'] ?? '';
+				$fluidTreeElem['isBottom'] = (!array_key_exists($index + 1, $constKeys) ||
+					$sourceTree[$level][$constKeys[$index + 1]]['parent'] !== $treeNode['parent']) ? 1 : 0;
+
+				$icons = $this->prepareTreeIcons($level, $treeHide, $fluidTreeElem, isset($treeNode['childs']));
+				$fluidTreeElem['icons'] = $icons;
+
+				if (array_key_exists($level + 1, $sourceTree)) {
+					$this->addLevelElementsToFluidTree(
+						$sourceTree,
+						$level + 1,
+						$constKey,
+						$fluidTreeElem,
+						$treeHide
+					);
+				}
+				if ($level > 0) {
+					$fluidTree['children'][$constKey] = $fluidTreeElem;
+				} else {
+					$fluidTree[$constKey] = $fluidTreeElem;
+				}
+			}
+			$index++;
+		}
+	}
+
+	/**
+	 * Sorts and adds icons in tree structure.
+	 *
+	 * @param int $level Tree level of constant.
+	 * @param boolean $treeHide Indicator which shows should all tree elements be closed (hidden) by default.
+	 * @param array $fluidTreeElem Element of tree which is built for use on fluid page.
+	 * @param boolean $hasChildren Indicator does this tree element have children
+	 * @return array
+	 */
+	protected function prepareTreeIcons(int $level, $treeHide, array $fluidTreeElem, $hasChildren): array {
+		$icons = [];
+		$leftMargins = [];
+		$marginLeftSpaceCounter = 0;
+		for ($iconLevel = $level, $currentFluidTreeElem = $fluidTreeElem;
+			$currentFluidTreeElem;
+			$iconLevel--, $currentFluidTreeElem = $currentFluidTreeElem['parent']) {
+			$iconName = '.png';
+			if ($iconLevel === $level) {
+				if ($currentFluidTreeElem['isBottom']) {
+					$iconName = 'Bottom' . $iconName;
+				}
+				if ($hasChildren) {
+					$iconName = 'tree' . ($treeHide && $level != 0 ? 'Plus' : 'Minus') . $iconName;
+				} else {
+					$iconName = 'join' . $iconName;
+				}
+			} else {
+				if (!$currentFluidTreeElem['isBottom']) {
+					$iconName = 'line' . $iconName;
+					$leftMargins[] = $marginLeftSpaceCounter;
+					$marginLeftSpaceCounter = 0;
+				} else {
+					$marginLeftSpaceCounter += $this->marginLeftSpaceUnit;
+					continue;
+				}
+			}
+			$icons[] = ['name' => $iconName];
+		}
+		$leftMargins[] = $marginLeftSpaceCounter;
+		for ($iterator = 0, $iconsSize = count($icons); $iterator < $iconsSize; $iterator++) {
+			$icons[$iterator]['marginLeft'] = $leftMargins[$iterator];
+		}
+		return $icons;
+	}
+}