nextcloud / server

lib/private/legacy/app.php

Indentation +1205 added lines, -1205 removed lines

@@ -61,1209 +61,1209 @@
  * upgrading and removing apps.
  */
 class OC_App {
-	static private $appVersion = [];
-	static private $adminForms = array();
-	static private $personalForms = array();
-	static private $appInfo = array();
-	static private $appTypes = array();
-	static private $loadedApps = array();
-	static private $altLogin = array();
-	static private $alreadyRegistered = [];
-	const officialApp = 200;
-
-	/**
-	 * clean the appId
-	 *
-	 * @param string|boolean $app AppId that needs to be cleaned
-	 * @return string
-	 */
-	public static function cleanAppId($app) {
-		return str_replace(array('\0', '/', '\\', '..'), '', $app);
-	}
-
-	/**
-	 * Check if an app is loaded
-	 *
-	 * @param string $app
-	 * @return bool
-	 */
-	public static function isAppLoaded($app) {
-		return in_array($app, self::$loadedApps, true);
-	}
-
-	/**
-	 * loads all apps
-	 *
-	 * @param string[] | string | null $types
-	 * @return bool
-	 *
-	 * This function walks through the ownCloud directory and loads all apps
-	 * it can find. A directory contains an app if the file /appinfo/info.xml
-	 * exists.
-	 *
-	 * if $types is set, only apps of those types will be loaded
-	 */
-	public static function loadApps($types = null) {
-		if (\OC::$server->getSystemConfig()->getValue('maintenance', false)) {
-			return false;
-		}
-		// Load the enabled apps here
-		$apps = self::getEnabledApps();
-
-		// Add each apps' folder as allowed class path
-		foreach($apps as $app) {
-			$path = self::getAppPath($app);
-			if($path !== false) {
-				self::registerAutoloading($app, $path);
-			}
-		}
-
-		// prevent app.php from printing output
-		ob_start();
-		foreach ($apps as $app) {
-			if ((is_null($types) or self::isType($app, $types)) && !in_array($app, self::$loadedApps)) {
-				self::loadApp($app);
-			}
-		}
-		ob_end_clean();
-
-		return true;
-	}
-
-	/**
-	 * load a single app
-	 *
-	 * @param string $app
-	 */
-	public static function loadApp($app) {
-		self::$loadedApps[] = $app;
-		$appPath = self::getAppPath($app);
-		if($appPath === false) {
-			return;
-		}
-
-		// in case someone calls loadApp() directly
-		self::registerAutoloading($app, $appPath);
-
-		if (is_file($appPath . '/appinfo/app.php')) {
-			\OC::$server->getEventLogger()->start('load_app_' . $app, 'Load app: ' . $app);
-			self::requireAppFile($app);
-			if (self::isType($app, array('authentication'))) {
-				// since authentication apps affect the "is app enabled for group" check,
-				// the enabled apps cache needs to be cleared to make sure that the
-				// next time getEnableApps() is called it will also include apps that were
-				// enabled for groups
-				self::$enabledAppsCache = array();
-			}
-			\OC::$server->getEventLogger()->end('load_app_' . $app);
-		}
-
-		$info = self::getAppInfo($app);
-		if (!empty($info['activity']['filters'])) {
-			foreach ($info['activity']['filters'] as $filter) {
-				\OC::$server->getActivityManager()->registerFilter($filter);
-			}
-		}
-		if (!empty($info['activity']['settings'])) {
-			foreach ($info['activity']['settings'] as $setting) {
-				\OC::$server->getActivityManager()->registerSetting($setting);
-			}
-		}
-		if (!empty($info['activity']['providers'])) {
-			foreach ($info['activity']['providers'] as $provider) {
-				\OC::$server->getActivityManager()->registerProvider($provider);
-			}
-		}
-		if (!empty($info['collaboration']['plugins'])) {
-			// deal with one or many plugin entries
-			$plugins = isset($info['collaboration']['plugins']['plugin']['@value']) ?
-				[$info['collaboration']['plugins']['plugin']] : $info['collaboration']['plugins']['plugin'];
-			foreach ($plugins as $plugin) {
-				if($plugin['@attributes']['type'] === 'collaborator-search') {
-					$pluginInfo = [
-						'shareType' => $plugin['@attributes']['share-type'],
-						'class' => $plugin['@value'],
-					];
-					\OC::$server->getCollaboratorSearch()->registerPlugin($pluginInfo);
-				}
-			}
-		}
-	}
-
-	/**
-	 * @internal
-	 * @param string $app
-	 * @param string $path
-	 */
-	public static function registerAutoloading($app, $path) {
-		$key = $app . '-' . $path;
-		if(isset(self::$alreadyRegistered[$key])) {
-			return;
-		}
-
-		self::$alreadyRegistered[$key] = true;
-
-		// Register on PSR-4 composer autoloader
-		$appNamespace = \OC\AppFramework\App::buildAppNamespace($app);
-		\OC::$server->registerNamespace($app, $appNamespace);
-
-		if (file_exists($path . '/composer/autoload.php')) {
-			require_once $path . '/composer/autoload.php';
-		} else {
-			\OC::$composerAutoloader->addPsr4($appNamespace . '\\', $path . '/lib/', true);
-			// Register on legacy autoloader
-			\OC::$loader->addValidRoot($path);
-		}
-
-		// Register Test namespace only when testing
-		if (defined('PHPUNIT_RUN') || defined('CLI_TEST_RUN')) {
-			\OC::$composerAutoloader->addPsr4($appNamespace . '\\Tests\\', $path . '/tests/', true);
-		}
-	}
-
-	/**
-	 * Load app.php from the given app
-	 *
-	 * @param string $app app name
-	 */
-	private static function requireAppFile($app) {
-		try {
-			// encapsulated here to avoid variable scope conflicts
-			require_once $app . '/appinfo/app.php';
-		} catch (Error $ex) {
-			\OC::$server->getLogger()->logException($ex);
-			$blacklist = \OC::$server->getAppManager()->getAlwaysEnabledApps();
-			if (!in_array($app, $blacklist)) {
-				self::disable($app);
-			}
-		}
-	}
-
-	/**
-	 * check if an app is of a specific type
-	 *
-	 * @param string $app
-	 * @param string|array $types
-	 * @return bool
-	 */
-	public static function isType($app, $types) {
-		if (is_string($types)) {
-			$types = array($types);
-		}
-		$appTypes = self::getAppTypes($app);
-		foreach ($types as $type) {
-			if (array_search($type, $appTypes) !== false) {
-				return true;
-			}
-		}
-		return false;
-	}
-
-	/**
-	 * get the types of an app
-	 *
-	 * @param string $app
-	 * @return array
-	 */
-	private static function getAppTypes($app) {
-		//load the cache
-		if (count(self::$appTypes) == 0) {
-			self::$appTypes = \OC::$server->getAppConfig()->getValues(false, 'types');
-		}
-
-		if (isset(self::$appTypes[$app])) {
-			return explode(',', self::$appTypes[$app]);
-		} else {
-			return array();
-		}
-	}
-
-	/**
-	 * read app types from info.xml and cache them in the database
-	 */
-	public static function setAppTypes($app) {
-		$appData = self::getAppInfo($app);
-		if(!is_array($appData)) {
-			return;
-		}
-
-		if (isset($appData['types'])) {
-			$appTypes = implode(',', $appData['types']);
-		} else {
-			$appTypes = '';
-			$appData['types'] = [];
-		}
-
-		\OC::$server->getAppConfig()->setValue($app, 'types', $appTypes);
-
-		if (\OC::$server->getAppManager()->hasProtectedAppType($appData['types'])) {
-			$enabled = \OC::$server->getAppConfig()->getValue($app, 'enabled', 'yes');
-			if ($enabled !== 'yes' && $enabled !== 'no') {
-				\OC::$server->getAppConfig()->setValue($app, 'enabled', 'yes');
-			}
-		}
-	}
-
-	/**
-	 * get all enabled apps
-	 */
-	protected static $enabledAppsCache = array();
-
-	/**
-	 * Returns apps enabled for the current user.
-	 *
-	 * @param bool $forceRefresh whether to refresh the cache
-	 * @param bool $all whether to return apps for all users, not only the
-	 * currently logged in one
-	 * @return string[]
-	 */
-	public static function getEnabledApps($forceRefresh = false, $all = false) {
-		if (!\OC::$server->getSystemConfig()->getValue('installed', false)) {
-			return array();
-		}
-		// in incognito mode or when logged out, $user will be false,
-		// which is also the case during an upgrade
-		$appManager = \OC::$server->getAppManager();
-		if ($all) {
-			$user = null;
-		} else {
-			$user = \OC::$server->getUserSession()->getUser();
-		}
-
-		if (is_null($user)) {
-			$apps = $appManager->getInstalledApps();
-		} else {
-			$apps = $appManager->getEnabledAppsForUser($user);
-		}
-		$apps = array_filter($apps, function ($app) {
-			return $app !== 'files';//we add this manually
-		});
-		sort($apps);
-		array_unshift($apps, 'files');
-		return $apps;
-	}
-
-	/**
-	 * checks whether or not an app is enabled
-	 *
-	 * @param string $app app
-	 * @return bool
-	 * @deprecated 13.0.0 use \OC::$server->getAppManager()->isEnabledForUser($appId)
-	 *
-	 * This function checks whether or not an app is enabled.
-	 */
-	public static function isEnabled($app) {
-		return \OC::$server->getAppManager()->isEnabledForUser($app);
-	}
-
-	/**
-	 * enables an app
-	 *
-	 * @param string $appId
-	 * @param array $groups (optional) when set, only these groups will have access to the app
-	 * @throws \Exception
-	 * @return void
-	 *
-	 * This function set an app as enabled in appconfig.
-	 */
-	public function enable($appId,
-						   $groups = null) {
-		self::$enabledAppsCache = []; // flush
-
-		// Check if app is already downloaded
-		$installer = new Installer(
-			\OC::$server->getAppFetcher(),
-			\OC::$server->getHTTPClientService(),
-			\OC::$server->getTempManager(),
-			\OC::$server->getLogger(),
-			\OC::$server->getConfig()
-		);
-		$isDownloaded = $installer->isDownloaded($appId);
-
-		if(!$isDownloaded) {
-			$installer->downloadApp($appId);
-		}
-
-		$installer->installApp($appId);
-
-		$appManager = \OC::$server->getAppManager();
-		if (!is_null($groups)) {
-			$groupManager = \OC::$server->getGroupManager();
-			$groupsList = [];
-			foreach ($groups as $group) {
-				$groupItem = $groupManager->get($group);
-				if ($groupItem instanceof \OCP\IGroup) {
-					$groupsList[] = $groupManager->get($group);
-				}
-			}
-			$appManager->enableAppForGroups($appId, $groupsList);
-		} else {
-			$appManager->enableApp($appId);
-		}
-	}
-
-	/**
-	 * @param string $app
-	 * @return bool
-	 */
-	public static function removeApp($app) {
-		if (\OC::$server->getAppManager()->isShipped($app)) {
-			return false;
-		}
-
-		$installer = new Installer(
-			\OC::$server->getAppFetcher(),
-			\OC::$server->getHTTPClientService(),
-			\OC::$server->getTempManager(),
-			\OC::$server->getLogger(),
-			\OC::$server->getConfig()
-		);
-		return $installer->removeApp($app);
-	}
-
-	/**
-	 * This function set an app as disabled in appconfig.
-	 *
-	 * @param string $app app
-	 * @throws Exception
-	 */
-	public static function disable($app) {
-		// flush
-		self::$enabledAppsCache = array();
-
-		// run uninstall steps
-		$appData = OC_App::getAppInfo($app);
-		if (!is_null($appData)) {
-			OC_App::executeRepairSteps($app, $appData['repair-steps']['uninstall']);
-		}
-
-		// emit disable hook - needed anymore ?
-		\OC_Hook::emit('OC_App', 'pre_disable', array('app' => $app));
-
-		// finally disable it
-		$appManager = \OC::$server->getAppManager();
-		$appManager->disableApp($app);
-	}
-
-	// This is private as well. It simply works, so don't ask for more details
-	private static function proceedNavigation($list) {
-		usort($list, function($a, $b) {
-			if (isset($a['order']) && isset($b['order'])) {
-				return ($a['order'] < $b['order']) ? -1 : 1;
-			} else if (isset($a['order']) || isset($b['order'])) {
-				return isset($a['order']) ? -1 : 1;
-			} else {
-				return ($a['name'] < $b['name']) ? -1 : 1;
-			}
-		});
-
-		$activeApp = OC::$server->getNavigationManager()->getActiveEntry();
-		foreach ($list as $index => &$navEntry) {
-			if ($navEntry['id'] == $activeApp) {
-				$navEntry['active'] = true;
-			} else {
-				$navEntry['active'] = false;
-			}
-		}
-		unset($navEntry);
-
-		return $list;
-	}
-
-	/**
-	 * Get the path where to install apps
-	 *
-	 * @return string|false
-	 */
-	public static function getInstallPath() {
-		if (\OC::$server->getSystemConfig()->getValue('appstoreenabled', true) == false) {
-			return false;
-		}
-
-		foreach (OC::$APPSROOTS as $dir) {
-			if (isset($dir['writable']) && $dir['writable'] === true) {
-				return $dir['path'];
-			}
-		}
-
-		\OCP\Util::writeLog('core', 'No application directories are marked as writable.', \OCP\Util::ERROR);
-		return null;
-	}
-
-
-	/**
-	 * search for an app in all app-directories
-	 *
-	 * @param string $appId
-	 * @return false|string
-	 */
-	public static function findAppInDirectories($appId) {
-		$sanitizedAppId = self::cleanAppId($appId);
-		if($sanitizedAppId !== $appId) {
-			return false;
-		}
-		static $app_dir = array();
-
-		if (isset($app_dir[$appId])) {
-			return $app_dir[$appId];
-		}
-
-		$possibleApps = array();
-		foreach (OC::$APPSROOTS as $dir) {
-			if (file_exists($dir['path'] . '/' . $appId)) {
-				$possibleApps[] = $dir;
-			}
-		}
-
-		if (empty($possibleApps)) {
-			return false;
-		} elseif (count($possibleApps) === 1) {
-			$dir = array_shift($possibleApps);
-			$app_dir[$appId] = $dir;
-			return $dir;
-		} else {
-			$versionToLoad = array();
-			foreach ($possibleApps as $possibleApp) {
-				$version = self::getAppVersionByPath($possibleApp['path']);
-				if (empty($versionToLoad) || version_compare($version, $versionToLoad['version'], '>')) {
-					$versionToLoad = array(
-						'dir' => $possibleApp,
-						'version' => $version,
-					);
-				}
-			}
-			$app_dir[$appId] = $versionToLoad['dir'];
-			return $versionToLoad['dir'];
-			//TODO - write test
-		}
-	}
-
-	/**
-	 * Get the directory for the given app.
-	 * If the app is defined in multiple directories, the first one is taken. (false if not found)
-	 *
-	 * @param string $appId
-	 * @return string|false
-	 */
-	public static function getAppPath($appId) {
-		if ($appId === null || trim($appId) === '') {
-			return false;
-		}
-
-		if (($dir = self::findAppInDirectories($appId)) != false) {
-			return $dir['path'] . '/' . $appId;
-		}
-		return false;
-	}
-
-	/**
-	 * Get the path for the given app on the access
-	 * If the app is defined in multiple directories, the first one is taken. (false if not found)
-	 *
-	 * @param string $appId
-	 * @return string|false
-	 */
-	public static function getAppWebPath($appId) {
-		if (($dir = self::findAppInDirectories($appId)) != false) {
-			return OC::$WEBROOT . $dir['url'] . '/' . $appId;
-		}
-		return false;
-	}
-
-	/**
-	 * get the last version of the app from appinfo/info.xml
-	 *
-	 * @param string $appId
-	 * @param bool $useCache
-	 * @return string
-	 */
-	public static function getAppVersion($appId, $useCache = true) {
-		if($useCache && isset(self::$appVersion[$appId])) {
-			return self::$appVersion[$appId];
-		}
-
-		$file = self::getAppPath($appId);
-		self::$appVersion[$appId] = ($file !== false) ? self::getAppVersionByPath($file) : '0';
-		return self::$appVersion[$appId];
-	}
-
-	/**
-	 * get app's version based on it's path
-	 *
-	 * @param string $path
-	 * @return string
-	 */
-	public static function getAppVersionByPath($path) {
-		$infoFile = $path . '/appinfo/info.xml';
-		$appData = self::getAppInfo($infoFile, true);
-		return isset($appData['version']) ? $appData['version'] : '';
-	}
-
-
-	/**
-	 * Read all app metadata from the info.xml file
-	 *
-	 * @param string $appId id of the app or the path of the info.xml file
-	 * @param bool $path
-	 * @param string $lang
-	 * @return array|null
-	 * @note all data is read from info.xml, not just pre-defined fields
-	 */
-	public static function getAppInfo($appId, $path = false, $lang = null) {
-		if ($path) {
-			$file = $appId;
-		} else {
-			if ($lang === null && isset(self::$appInfo[$appId])) {
-				return self::$appInfo[$appId];
-			}
-			$appPath = self::getAppPath($appId);
-			if($appPath === false) {
-				return null;
-			}
-			$file = $appPath . '/appinfo/info.xml';
-		}
-
-		$parser = new InfoParser(\OC::$server->getMemCacheFactory()->createLocal('core.appinfo'));
-		$data = $parser->parse($file);
-
-		if (is_array($data)) {
-			$data = OC_App::parseAppInfo($data, $lang);
-		}
-		if(isset($data['ocsid'])) {
-			$storedId = \OC::$server->getConfig()->getAppValue($appId, 'ocsid');
-			if($storedId !== '' && $storedId !== $data['ocsid']) {
-				$data['ocsid'] = $storedId;
-			}
-		}
-
-		if ($lang === null) {
-			self::$appInfo[$appId] = $data;
-		}
-
-		return $data;
-	}
-
-	/**
-	 * Returns the navigation
-	 *
-	 * @return array
-	 *
-	 * This function returns an array containing all entries added. The
-	 * entries are sorted by the key 'order' ascending. Additional to the keys
-	 * given for each app the following keys exist:
-	 *   - active: boolean, signals if the user is on this navigation entry
-	 */
-	public static function getNavigation() {
-		$entries = OC::$server->getNavigationManager()->getAll();
-		return self::proceedNavigation($entries);
-	}
-
-	/**
-	 * Returns the Settings Navigation
-	 *
-	 * @return string[]
-	 *
-	 * This function returns an array containing all settings pages added. The
-	 * entries are sorted by the key 'order' ascending.
-	 */
-	public static function getSettingsNavigation() {
-		$entries = OC::$server->getNavigationManager()->getAll('settings');
-		return self::proceedNavigation($entries);
-	}
-
-	/**
-	 * get the id of loaded app
-	 *
-	 * @return string
-	 */
-	public static function getCurrentApp() {
-		$request = \OC::$server->getRequest();
-		$script = substr($request->getScriptName(), strlen(OC::$WEBROOT) + 1);
-		$topFolder = substr($script, 0, strpos($script, '/'));
-		if (empty($topFolder)) {
-			$path_info = $request->getPathInfo();
-			if ($path_info) {
-				$topFolder = substr($path_info, 1, strpos($path_info, '/', 1) - 1);
-			}
-		}
-		if ($topFolder == 'apps') {
-			$length = strlen($topFolder);
-			return substr($script, $length + 1, strpos($script, '/', $length + 1) - $length - 1);
-		} else {
-			return $topFolder;
-		}
-	}
-
-	/**
-	 * @param string $type
-	 * @return array
-	 */
-	public static function getForms($type) {
-		$forms = array();
-		switch ($type) {
-			case 'admin':
-				$source = self::$adminForms;
-				break;
-			case 'personal':
-				$source = self::$personalForms;
-				break;
-			default:
-				return array();
-		}
-		foreach ($source as $form) {
-			$forms[] = include $form;
-		}
-		return $forms;
-	}
-
-	/**
-	 * register an admin form to be shown
-	 *
-	 * @param string $app
-	 * @param string $page
-	 */
-	public static function registerAdmin($app, $page) {
-		self::$adminForms[] = $app . '/' . $page . '.php';
-	}
-
-	/**
-	 * register a personal form to be shown
-	 * @param string $app
-	 * @param string $page
-	 */
-	public static function registerPersonal($app, $page) {
-		self::$personalForms[] = $app . '/' . $page . '.php';
-	}
-
-	/**
-	 * @param array $entry
-	 */
-	public static function registerLogIn(array $entry) {
-		self::$altLogin[] = $entry;
-	}
-
-	/**
-	 * @return array
-	 */
-	public static function getAlternativeLogIns() {
-		return self::$altLogin;
-	}
-
-	/**
-	 * get a list of all apps in the apps folder
-	 *
-	 * @return array an array of app names (string IDs)
-	 * @todo: change the name of this method to getInstalledApps, which is more accurate
-	 */
-	public static function getAllApps() {
-
-		$apps = array();
-
-		foreach (OC::$APPSROOTS as $apps_dir) {
-			if (!is_readable($apps_dir['path'])) {
-				\OCP\Util::writeLog('core', 'unable to read app folder : ' . $apps_dir['path'], \OCP\Util::WARN);
-				continue;
-			}
-			$dh = opendir($apps_dir['path']);
-
-			if (is_resource($dh)) {
-				while (($file = readdir($dh)) !== false) {
-
-					if ($file[0] != '.' and is_dir($apps_dir['path'] . '/' . $file) and is_file($apps_dir['path'] . '/' . $file . '/appinfo/info.xml')) {
-
-						$apps[] = $file;
-					}
-				}
-			}
-		}
-
-		$apps = array_unique($apps);
-
-		return $apps;
-	}
-
-	/**
-	 * List all apps, this is used in apps.php
-	 *
-	 * @return array
-	 */
-	public function listAllApps() {
-		$installedApps = OC_App::getAllApps();
-
-		$appManager = \OC::$server->getAppManager();
-		//we don't want to show configuration for these
-		$blacklist = $appManager->getAlwaysEnabledApps();
-		$appList = array();
-		$langCode = \OC::$server->getL10N('core')->getLanguageCode();
-		$urlGenerator = \OC::$server->getURLGenerator();
-
-		foreach ($installedApps as $app) {
-			if (array_search($app, $blacklist) === false) {
-
-				$info = OC_App::getAppInfo($app, false, $langCode);
-				if (!is_array($info)) {
-					\OCP\Util::writeLog('core', 'Could not read app info file for app "' . $app . '"', \OCP\Util::ERROR);
-					continue;
-				}
-
-				if (!isset($info['name'])) {
-					\OCP\Util::writeLog('core', 'App id "' . $app . '" has no name in appinfo', \OCP\Util::ERROR);
-					continue;
-				}
-
-				$enabled = \OC::$server->getAppConfig()->getValue($app, 'enabled', 'no');
-				$info['groups'] = null;
-				if ($enabled === 'yes') {
-					$active = true;
-				} else if ($enabled === 'no') {
-					$active = false;
-				} else {
-					$active = true;
-					$info['groups'] = $enabled;
-				}
-
-				$info['active'] = $active;
-
-				if ($appManager->isShipped($app)) {
-					$info['internal'] = true;
-					$info['level'] = self::officialApp;
-					$info['removable'] = false;
-				} else {
-					$info['internal'] = false;
-					$info['removable'] = true;
-				}
-
-				$appPath = self::getAppPath($app);
-				if($appPath !== false) {
-					$appIcon = $appPath . '/img/' . $app . '.svg';
-					if (file_exists($appIcon)) {
-						$info['preview'] = $urlGenerator->imagePath($app, $app . '.svg');
-						$info['previewAsIcon'] = true;
-					} else {
-						$appIcon = $appPath . '/img/app.svg';
-						if (file_exists($appIcon)) {
-							$info['preview'] = $urlGenerator->imagePath($app, 'app.svg');
-							$info['previewAsIcon'] = true;
-						}
-					}
-				}
-				// fix documentation
-				if (isset($info['documentation']) && is_array($info['documentation'])) {
-					foreach ($info['documentation'] as $key => $url) {
-						// If it is not an absolute URL we assume it is a key
-						// i.e. admin-ldap will get converted to go.php?to=admin-ldap
-						if (stripos($url, 'https://') !== 0 && stripos($url, 'http://') !== 0) {
-							$url = $urlGenerator->linkToDocs($url);
-						}
-
-						$info['documentation'][$key] = $url;
-					}
-				}
-
-				$info['version'] = OC_App::getAppVersion($app);
-				$appList[] = $info;
-			}
-		}
-
-		return $appList;
-	}
-
-	/**
-	 * Returns the internal app ID or false
-	 * @param string $ocsID
-	 * @return string|false
-	 */
-	public static function getInternalAppIdByOcs($ocsID) {
-		if(is_numeric($ocsID)) {
-			$idArray = \OC::$server->getAppConfig()->getValues(false, 'ocsid');
-			if(array_search($ocsID, $idArray)) {
-				return array_search($ocsID, $idArray);
-			}
-		}
-		return false;
-	}
-
-	public static function shouldUpgrade($app) {
-		$versions = self::getAppVersions();
-		$currentVersion = OC_App::getAppVersion($app);
-		if ($currentVersion && isset($versions[$app])) {
-			$installedVersion = $versions[$app];
-			if (!version_compare($currentVersion, $installedVersion, '=')) {
-				return true;
-			}
-		}
-		return false;
-	}
-
-	/**
-	 * Adjust the number of version parts of $version1 to match
-	 * the number of version parts of $version2.
-	 *
-	 * @param string $version1 version to adjust
-	 * @param string $version2 version to take the number of parts from
-	 * @return string shortened $version1
-	 */
-	private static function adjustVersionParts($version1, $version2) {
-		$version1 = explode('.', $version1);
-		$version2 = explode('.', $version2);
-		// reduce $version1 to match the number of parts in $version2
-		while (count($version1) > count($version2)) {
-			array_pop($version1);
-		}
-		// if $version1 does not have enough parts, add some
-		while (count($version1) < count($version2)) {
-			$version1[] = '0';
-		}
-		return implode('.', $version1);
-	}
-
-	/**
-	 * Check whether the current ownCloud version matches the given
-	 * application's version requirements.
-	 *
-	 * The comparison is made based on the number of parts that the
-	 * app info version has. For example for ownCloud 6.0.3 if the
-	 * app info version is expecting version 6.0, the comparison is
-	 * made on the first two parts of the ownCloud version.
-	 * This means that it's possible to specify "requiremin" => 6
-	 * and "requiremax" => 6 and it will still match ownCloud 6.0.3.
-	 *
-	 * @param string $ocVersion ownCloud version to check against
-	 * @param array $appInfo app info (from xml)
-	 *
-	 * @return boolean true if compatible, otherwise false
-	 */
-	public static function isAppCompatible($ocVersion, $appInfo) {
-		$requireMin = '';
-		$requireMax = '';
-		if (isset($appInfo['dependencies']['nextcloud']['@attributes']['min-version'])) {
-			$requireMin = $appInfo['dependencies']['nextcloud']['@attributes']['min-version'];
-		} elseif (isset($appInfo['dependencies']['owncloud']['@attributes']['min-version'])) {
-			$requireMin = $appInfo['dependencies']['owncloud']['@attributes']['min-version'];
-		} else if (isset($appInfo['requiremin'])) {
-			$requireMin = $appInfo['requiremin'];
-		} else if (isset($appInfo['require'])) {
-			$requireMin = $appInfo['require'];
-		}
-
-		if (isset($appInfo['dependencies']['nextcloud']['@attributes']['max-version'])) {
-			$requireMax = $appInfo['dependencies']['nextcloud']['@attributes']['max-version'];
-		} elseif (isset($appInfo['dependencies']['owncloud']['@attributes']['max-version'])) {
-			$requireMax = $appInfo['dependencies']['owncloud']['@attributes']['max-version'];
-		} else if (isset($appInfo['requiremax'])) {
-			$requireMax = $appInfo['requiremax'];
-		}
-
-		if (is_array($ocVersion)) {
-			$ocVersion = implode('.', $ocVersion);
-		}
-
-		if (!empty($requireMin)
-			&& version_compare(self::adjustVersionParts($ocVersion, $requireMin), $requireMin, '<')
-		) {
-
-			return false;
-		}
-
-		if (!empty($requireMax)
-			&& version_compare(self::adjustVersionParts($ocVersion, $requireMax), $requireMax, '>')
-		) {
-			return false;
-		}
-
-		return true;
-	}
-
-	/**
-	 * get the installed version of all apps
-	 */
-	public static function getAppVersions() {
-		static $versions;
-
-		if(!$versions) {
-			$appConfig = \OC::$server->getAppConfig();
-			$versions = $appConfig->getValues(false, 'installed_version');
-		}
-		return $versions;
-	}
-
-	/**
-	 * @param string $app
-	 * @param \OCP\IConfig $config
-	 * @param \OCP\IL10N $l
-	 * @return bool
-	 *
-	 * @throws Exception if app is not compatible with this version of ownCloud
-	 * @throws Exception if no app-name was specified
-	 */
-	public function installApp($app,
-							   \OCP\IConfig $config,
-							   \OCP\IL10N $l) {
-		if ($app !== false) {
-			// check if the app is compatible with this version of ownCloud
-			$info = self::getAppInfo($app);
-			if(!is_array($info)) {
-				throw new \Exception(
-					$l->t('App "%s" cannot be installed because appinfo file cannot be read.',
-						[$info['name']]
-					)
-				);
-			}
-
-			$version = \OCP\Util::getVersion();
-			if (!self::isAppCompatible($version, $info)) {
-				throw new \Exception(
-					$l->t('App "%s" cannot be installed because it is not compatible with this version of the server.',
-						array($info['name'])
-					)
-				);
-			}
-
-			// check for required dependencies
-			self::checkAppDependencies($config, $l, $info);
-
-			$config->setAppValue($app, 'enabled', 'yes');
-			if (isset($appData['id'])) {
-				$config->setAppValue($app, 'ocsid', $appData['id']);
-			}
-
-			if(isset($info['settings']) && is_array($info['settings'])) {
-				$appPath = self::getAppPath($app);
-				self::registerAutoloading($app, $appPath);
-				\OC::$server->getSettingsManager()->setupSettings($info['settings']);
-			}
-
-			\OC_Hook::emit('OC_App', 'post_enable', array('app' => $app));
-		} else {
-			if(empty($appName) ) {
-				throw new \Exception($l->t("No app name specified"));
-			} else {
-				throw new \Exception($l->t("App '%s' could not be installed!", $appName));
-			}
-		}
-
-		return $app;
-	}
-
-	/**
-	 * update the database for the app and call the update script
-	 *
-	 * @param string $appId
-	 * @return bool
-	 */
-	public static function updateApp($appId) {
-		$appPath = self::getAppPath($appId);
-		if($appPath === false) {
-			return false;
-		}
-		self::registerAutoloading($appId, $appPath);
-
-		$appData = self::getAppInfo($appId);
-		self::executeRepairSteps($appId, $appData['repair-steps']['pre-migration']);
-
-		if (file_exists($appPath . '/appinfo/database.xml')) {
-			OC_DB::updateDbFromStructure($appPath . '/appinfo/database.xml');
-		} else {
-			$ms = new MigrationService($appId, \OC::$server->getDatabaseConnection());
-			$ms->migrate();
-		}
-
-		self::executeRepairSteps($appId, $appData['repair-steps']['post-migration']);
-		self::setupLiveMigrations($appId, $appData['repair-steps']['live-migration']);
-		unset(self::$appVersion[$appId]);
-
-		// run upgrade code
-		if (file_exists($appPath . '/appinfo/update.php')) {
-			self::loadApp($appId);
-			include $appPath . '/appinfo/update.php';
-		}
-		self::setupBackgroundJobs($appData['background-jobs']);
-		if(isset($appData['settings']) && is_array($appData['settings'])) {
-			\OC::$server->getSettingsManager()->setupSettings($appData['settings']);
-		}
-
-		//set remote/public handlers
-		if (array_key_exists('ocsid', $appData)) {
-			\OC::$server->getConfig()->setAppValue($appId, 'ocsid', $appData['ocsid']);
-		} elseif(\OC::$server->getConfig()->getAppValue($appId, 'ocsid', null) !== null) {
-			\OC::$server->getConfig()->deleteAppValue($appId, 'ocsid');
-		}
-		foreach ($appData['remote'] as $name => $path) {
-			\OC::$server->getConfig()->setAppValue('core', 'remote_' . $name, $appId . '/' . $path);
-		}
-		foreach ($appData['public'] as $name => $path) {
-			\OC::$server->getConfig()->setAppValue('core', 'public_' . $name, $appId . '/' . $path);
-		}
-
-		self::setAppTypes($appId);
-
-		$version = \OC_App::getAppVersion($appId);
-		\OC::$server->getAppConfig()->setValue($appId, 'installed_version', $version);
-
-		\OC::$server->getEventDispatcher()->dispatch(ManagerEvent::EVENT_APP_UPDATE, new ManagerEvent(
-			ManagerEvent::EVENT_APP_UPDATE, $appId
-		));
-
-		return true;
-	}
-
-	/**
-	 * @param string $appId
-	 * @param string[] $steps
-	 * @throws \OC\NeedsUpdateException
-	 */
-	public static function executeRepairSteps($appId, array $steps) {
-		if (empty($steps)) {
-			return;
-		}
-		// load the app
-		self::loadApp($appId);
-
-		$dispatcher = OC::$server->getEventDispatcher();
-
-		// load the steps
-		$r = new Repair([], $dispatcher);
-		foreach ($steps as $step) {
-			try {
-				$r->addStep($step);
-			} catch (Exception $ex) {
-				$r->emit('\OC\Repair', 'error', [$ex->getMessage()]);
-				\OC::$server->getLogger()->logException($ex);
-			}
-		}
-		// run the steps
-		$r->run();
-	}
-
-	public static function setupBackgroundJobs(array $jobs) {
-		$queue = \OC::$server->getJobList();
-		foreach ($jobs as $job) {
-			$queue->add($job);
-		}
-	}
-
-	/**
-	 * @param string $appId
-	 * @param string[] $steps
-	 */
-	private static function setupLiveMigrations($appId, array $steps) {
-		$queue = \OC::$server->getJobList();
-		foreach ($steps as $step) {
-			$queue->add('OC\Migration\BackgroundRepair', [
-				'app' => $appId,
-				'step' => $step]);
-		}
-	}
-
-	/**
-	 * @param string $appId
-	 * @return \OC\Files\View|false
-	 */
-	public static function getStorage($appId) {
-		if (\OC::$server->getAppManager()->isEnabledForUser($appId)) { //sanity check
-			if (\OC::$server->getUserSession()->isLoggedIn()) {
-				$view = new \OC\Files\View('/' . OC_User::getUser());
-				if (!$view->file_exists($appId)) {
-					$view->mkdir($appId);
-				}
-				return new \OC\Files\View('/' . OC_User::getUser() . '/' . $appId);
-			} else {
-				\OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ', user not logged in', \OCP\Util::ERROR);
-				return false;
-			}
-		} else {
-			\OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ' not enabled', \OCP\Util::ERROR);
-			return false;
-		}
-	}
-
-	protected static function findBestL10NOption($options, $lang) {
-		$fallback = $similarLangFallback = $englishFallback = false;
-
-		$lang = strtolower($lang);
-		$similarLang = $lang;
-		if (strpos($similarLang, '_')) {
-			// For "de_DE" we want to find "de" and the other way around
-			$similarLang = substr($lang, 0, strpos($lang, '_'));
-		}
-
-		foreach ($options as $option) {
-			if (is_array($option)) {
-				if ($fallback === false) {
-					$fallback = $option['@value'];
-				}
-
-				if (!isset($option['@attributes']['lang'])) {
-					continue;
-				}
-
-				$attributeLang = strtolower($option['@attributes']['lang']);
-				if ($attributeLang === $lang) {
-					return $option['@value'];
-				}
-
-				if ($attributeLang === $similarLang) {
-					$similarLangFallback = $option['@value'];
-				} else if (strpos($attributeLang, $similarLang . '_') === 0) {
-					if ($similarLangFallback === false) {
-						$similarLangFallback =  $option['@value'];
-					}
-				}
-			} else {
-				$englishFallback = $option;
-			}
-		}
-
-		if ($similarLangFallback !== false) {
-			return $similarLangFallback;
-		} else if ($englishFallback !== false) {
-			return $englishFallback;
-		}
-		return (string) $fallback;
-	}
-
-	/**
-	 * parses the app data array and enhanced the 'description' value
-	 *
-	 * @param array $data the app data
-	 * @param string $lang
-	 * @return array improved app data
-	 */
-	public static function parseAppInfo(array $data, $lang = null) {
-
-		if ($lang && isset($data['name']) && is_array($data['name'])) {
-			$data['name'] = self::findBestL10NOption($data['name'], $lang);
-		}
-		if ($lang && isset($data['summary']) && is_array($data['summary'])) {
-			$data['summary'] = self::findBestL10NOption($data['summary'], $lang);
-		}
-		if ($lang && isset($data['description']) && is_array($data['description'])) {
-			$data['description'] = trim(self::findBestL10NOption($data['description'], $lang));
-		} else if (isset($data['description']) && is_string($data['description'])) {
-			$data['description'] = trim($data['description']);
-		} else  {
-			$data['description'] = '';
-		}
-
-		return $data;
-	}
-
-	/**
-	 * @param \OCP\IConfig $config
-	 * @param \OCP\IL10N $l
-	 * @param array $info
-	 * @throws \Exception
-	 */
-	public static function checkAppDependencies($config, $l, $info) {
-		$dependencyAnalyzer = new DependencyAnalyzer(new Platform($config), $l);
-		$missing = $dependencyAnalyzer->analyze($info);
-		if (!empty($missing)) {
-			$missingMsg = implode(PHP_EOL, $missing);
-			throw new \Exception(
-				$l->t('App "%s" cannot be installed because the following dependencies are not fulfilled: %s',
-					[$info['name'], $missingMsg]
-				)
-			);
-		}
-	}
+    static private $appVersion = [];
+    static private $adminForms = array();
+    static private $personalForms = array();
+    static private $appInfo = array();
+    static private $appTypes = array();
+    static private $loadedApps = array();
+    static private $altLogin = array();
+    static private $alreadyRegistered = [];
+    const officialApp = 200;
+
+    /**
+     * clean the appId
+     *
+     * @param string|boolean $app AppId that needs to be cleaned
+     * @return string
+     */
+    public static function cleanAppId($app) {
+        return str_replace(array('\0', '/', '\\', '..'), '', $app);
+    }
+
+    /**
+     * Check if an app is loaded
+     *
+     * @param string $app
+     * @return bool
+     */
+    public static function isAppLoaded($app) {
+        return in_array($app, self::$loadedApps, true);
+    }
+
+    /**
+     * loads all apps
+     *
+     * @param string[] | string | null $types
+     * @return bool
+     *
+     * This function walks through the ownCloud directory and loads all apps
+     * it can find. A directory contains an app if the file /appinfo/info.xml
+     * exists.
+     *
+     * if $types is set, only apps of those types will be loaded
+     */
+    public static function loadApps($types = null) {
+        if (\OC::$server->getSystemConfig()->getValue('maintenance', false)) {
+            return false;
+        }
+        // Load the enabled apps here
+        $apps = self::getEnabledApps();
+
+        // Add each apps' folder as allowed class path
+        foreach($apps as $app) {
+            $path = self::getAppPath($app);
+            if($path !== false) {
+                self::registerAutoloading($app, $path);
+            }
+        }
+
+        // prevent app.php from printing output
+        ob_start();
+        foreach ($apps as $app) {
+            if ((is_null($types) or self::isType($app, $types)) && !in_array($app, self::$loadedApps)) {
+                self::loadApp($app);
+            }
+        }
+        ob_end_clean();
+
+        return true;
+    }
+
+    /**
+     * load a single app
+     *
+     * @param string $app
+     */
+    public static function loadApp($app) {
+        self::$loadedApps[] = $app;
+        $appPath = self::getAppPath($app);
+        if($appPath === false) {
+            return;
+        }
+
+        // in case someone calls loadApp() directly
+        self::registerAutoloading($app, $appPath);
+
+        if (is_file($appPath . '/appinfo/app.php')) {
+            \OC::$server->getEventLogger()->start('load_app_' . $app, 'Load app: ' . $app);
+            self::requireAppFile($app);
+            if (self::isType($app, array('authentication'))) {
+                // since authentication apps affect the "is app enabled for group" check,
+                // the enabled apps cache needs to be cleared to make sure that the
+                // next time getEnableApps() is called it will also include apps that were
+                // enabled for groups
+                self::$enabledAppsCache = array();
+            }
+            \OC::$server->getEventLogger()->end('load_app_' . $app);
+        }
+
+        $info = self::getAppInfo($app);
+        if (!empty($info['activity']['filters'])) {
+            foreach ($info['activity']['filters'] as $filter) {
+                \OC::$server->getActivityManager()->registerFilter($filter);
+            }
+        }
+        if (!empty($info['activity']['settings'])) {
+            foreach ($info['activity']['settings'] as $setting) {
+                \OC::$server->getActivityManager()->registerSetting($setting);
+            }
+        }
+        if (!empty($info['activity']['providers'])) {
+            foreach ($info['activity']['providers'] as $provider) {
+                \OC::$server->getActivityManager()->registerProvider($provider);
+            }
+        }
+        if (!empty($info['collaboration']['plugins'])) {
+            // deal with one or many plugin entries
+            $plugins = isset($info['collaboration']['plugins']['plugin']['@value']) ?
+                [$info['collaboration']['plugins']['plugin']] : $info['collaboration']['plugins']['plugin'];
+            foreach ($plugins as $plugin) {
+                if($plugin['@attributes']['type'] === 'collaborator-search') {
+                    $pluginInfo = [
+                        'shareType' => $plugin['@attributes']['share-type'],
+                        'class' => $plugin['@value'],
+                    ];
+                    \OC::$server->getCollaboratorSearch()->registerPlugin($pluginInfo);
+                }
+            }
+        }
+    }
+
+    /**
+     * @internal
+     * @param string $app
+     * @param string $path
+     */
+    public static function registerAutoloading($app, $path) {
+        $key = $app . '-' . $path;
+        if(isset(self::$alreadyRegistered[$key])) {
+            return;
+        }
+
+        self::$alreadyRegistered[$key] = true;
+
+        // Register on PSR-4 composer autoloader
+        $appNamespace = \OC\AppFramework\App::buildAppNamespace($app);
+        \OC::$server->registerNamespace($app, $appNamespace);
+
+        if (file_exists($path . '/composer/autoload.php')) {
+            require_once $path . '/composer/autoload.php';
+        } else {
+            \OC::$composerAutoloader->addPsr4($appNamespace . '\\', $path . '/lib/', true);
+            // Register on legacy autoloader
+            \OC::$loader->addValidRoot($path);
+        }
+
+        // Register Test namespace only when testing
+        if (defined('PHPUNIT_RUN') || defined('CLI_TEST_RUN')) {
+            \OC::$composerAutoloader->addPsr4($appNamespace . '\\Tests\\', $path . '/tests/', true);
+        }
+    }
+
+    /**
+     * Load app.php from the given app
+     *
+     * @param string $app app name
+     */
+    private static function requireAppFile($app) {
+        try {
+            // encapsulated here to avoid variable scope conflicts
+            require_once $app . '/appinfo/app.php';
+        } catch (Error $ex) {
+            \OC::$server->getLogger()->logException($ex);
+            $blacklist = \OC::$server->getAppManager()->getAlwaysEnabledApps();
+            if (!in_array($app, $blacklist)) {
+                self::disable($app);
+            }
+        }
+    }
+
+    /**
+     * check if an app is of a specific type
+     *
+     * @param string $app
+     * @param string|array $types
+     * @return bool
+     */
+    public static function isType($app, $types) {
+        if (is_string($types)) {
+            $types = array($types);
+        }
+        $appTypes = self::getAppTypes($app);
+        foreach ($types as $type) {
+            if (array_search($type, $appTypes) !== false) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * get the types of an app
+     *
+     * @param string $app
+     * @return array
+     */
+    private static function getAppTypes($app) {
+        //load the cache
+        if (count(self::$appTypes) == 0) {
+            self::$appTypes = \OC::$server->getAppConfig()->getValues(false, 'types');
+        }
+
+        if (isset(self::$appTypes[$app])) {
+            return explode(',', self::$appTypes[$app]);
+        } else {
+            return array();
+        }
+    }
+
+    /**
+     * read app types from info.xml and cache them in the database
+     */
+    public static function setAppTypes($app) {
+        $appData = self::getAppInfo($app);
+        if(!is_array($appData)) {
+            return;
+        }
+
+        if (isset($appData['types'])) {
+            $appTypes = implode(',', $appData['types']);
+        } else {
+            $appTypes = '';
+            $appData['types'] = [];
+        }
+
+        \OC::$server->getAppConfig()->setValue($app, 'types', $appTypes);
+
+        if (\OC::$server->getAppManager()->hasProtectedAppType($appData['types'])) {
+            $enabled = \OC::$server->getAppConfig()->getValue($app, 'enabled', 'yes');
+            if ($enabled !== 'yes' && $enabled !== 'no') {
+                \OC::$server->getAppConfig()->setValue($app, 'enabled', 'yes');
+            }
+        }
+    }
+
+    /**
+     * get all enabled apps
+     */
+    protected static $enabledAppsCache = array();
+
+    /**
+     * Returns apps enabled for the current user.
+     *
+     * @param bool $forceRefresh whether to refresh the cache
+     * @param bool $all whether to return apps for all users, not only the
+     * currently logged in one
+     * @return string[]
+     */
+    public static function getEnabledApps($forceRefresh = false, $all = false) {
+        if (!\OC::$server->getSystemConfig()->getValue('installed', false)) {
+            return array();
+        }
+        // in incognito mode or when logged out, $user will be false,
+        // which is also the case during an upgrade
+        $appManager = \OC::$server->getAppManager();
+        if ($all) {
+            $user = null;
+        } else {
+            $user = \OC::$server->getUserSession()->getUser();
+        }
+
+        if (is_null($user)) {
+            $apps = $appManager->getInstalledApps();
+        } else {
+            $apps = $appManager->getEnabledAppsForUser($user);
+        }
+        $apps = array_filter($apps, function ($app) {
+            return $app !== 'files';//we add this manually
+        });
+        sort($apps);
+        array_unshift($apps, 'files');
+        return $apps;
+    }
+
+    /**
+     * checks whether or not an app is enabled
+     *
+     * @param string $app app
+     * @return bool
+     * @deprecated 13.0.0 use \OC::$server->getAppManager()->isEnabledForUser($appId)
+     *
+     * This function checks whether or not an app is enabled.
+     */
+    public static function isEnabled($app) {
+        return \OC::$server->getAppManager()->isEnabledForUser($app);
+    }
+
+    /**
+     * enables an app
+     *
+     * @param string $appId
+     * @param array $groups (optional) when set, only these groups will have access to the app
+     * @throws \Exception
+     * @return void
+     *
+     * This function set an app as enabled in appconfig.
+     */
+    public function enable($appId,
+                            $groups = null) {
+        self::$enabledAppsCache = []; // flush
+
+        // Check if app is already downloaded
+        $installer = new Installer(
+            \OC::$server->getAppFetcher(),
+            \OC::$server->getHTTPClientService(),
+            \OC::$server->getTempManager(),
+            \OC::$server->getLogger(),
+            \OC::$server->getConfig()
+        );
+        $isDownloaded = $installer->isDownloaded($appId);
+
+        if(!$isDownloaded) {
+            $installer->downloadApp($appId);
+        }
+
+        $installer->installApp($appId);
+
+        $appManager = \OC::$server->getAppManager();
+        if (!is_null($groups)) {
+            $groupManager = \OC::$server->getGroupManager();
+            $groupsList = [];
+            foreach ($groups as $group) {
+                $groupItem = $groupManager->get($group);
+                if ($groupItem instanceof \OCP\IGroup) {
+                    $groupsList[] = $groupManager->get($group);
+                }
+            }
+            $appManager->enableAppForGroups($appId, $groupsList);
+        } else {
+            $appManager->enableApp($appId);
+        }
+    }
+
+    /**
+     * @param string $app
+     * @return bool
+     */
+    public static function removeApp($app) {
+        if (\OC::$server->getAppManager()->isShipped($app)) {
+            return false;
+        }
+
+        $installer = new Installer(
+            \OC::$server->getAppFetcher(),
+            \OC::$server->getHTTPClientService(),
+            \OC::$server->getTempManager(),
+            \OC::$server->getLogger(),
+            \OC::$server->getConfig()
+        );
+        return $installer->removeApp($app);
+    }
+
+    /**
+     * This function set an app as disabled in appconfig.
+     *
+     * @param string $app app
+     * @throws Exception
+     */
+    public static function disable($app) {
+        // flush
+        self::$enabledAppsCache = array();
+
+        // run uninstall steps
+        $appData = OC_App::getAppInfo($app);
+        if (!is_null($appData)) {
+            OC_App::executeRepairSteps($app, $appData['repair-steps']['uninstall']);
+        }
+
+        // emit disable hook - needed anymore ?
+        \OC_Hook::emit('OC_App', 'pre_disable', array('app' => $app));
+
+        // finally disable it
+        $appManager = \OC::$server->getAppManager();
+        $appManager->disableApp($app);
+    }
+
+    // This is private as well. It simply works, so don't ask for more details
+    private static function proceedNavigation($list) {
+        usort($list, function($a, $b) {
+            if (isset($a['order']) && isset($b['order'])) {
+                return ($a['order'] < $b['order']) ? -1 : 1;
+            } else if (isset($a['order']) || isset($b['order'])) {
+                return isset($a['order']) ? -1 : 1;
+            } else {
+                return ($a['name'] < $b['name']) ? -1 : 1;
+            }
+        });
+
+        $activeApp = OC::$server->getNavigationManager()->getActiveEntry();
+        foreach ($list as $index => &$navEntry) {
+            if ($navEntry['id'] == $activeApp) {
+                $navEntry['active'] = true;
+            } else {
+                $navEntry['active'] = false;
+            }
+        }
+        unset($navEntry);
+
+        return $list;
+    }
+
+    /**
+     * Get the path where to install apps
+     *
+     * @return string|false
+     */
+    public static function getInstallPath() {
+        if (\OC::$server->getSystemConfig()->getValue('appstoreenabled', true) == false) {
+            return false;
+        }
+
+        foreach (OC::$APPSROOTS as $dir) {
+            if (isset($dir['writable']) && $dir['writable'] === true) {
+                return $dir['path'];
+            }
+        }
+
+        \OCP\Util::writeLog('core', 'No application directories are marked as writable.', \OCP\Util::ERROR);
+        return null;
+    }
+
+
+    /**
+     * search for an app in all app-directories
+     *
+     * @param string $appId
+     * @return false|string
+     */
+    public static function findAppInDirectories($appId) {
+        $sanitizedAppId = self::cleanAppId($appId);
+        if($sanitizedAppId !== $appId) {
+            return false;
+        }
+        static $app_dir = array();
+
+        if (isset($app_dir[$appId])) {
+            return $app_dir[$appId];
+        }
+
+        $possibleApps = array();
+        foreach (OC::$APPSROOTS as $dir) {
+            if (file_exists($dir['path'] . '/' . $appId)) {
+                $possibleApps[] = $dir;
+            }
+        }
+
+        if (empty($possibleApps)) {
+            return false;
+        } elseif (count($possibleApps) === 1) {
+            $dir = array_shift($possibleApps);
+            $app_dir[$appId] = $dir;
+            return $dir;
+        } else {
+            $versionToLoad = array();
+            foreach ($possibleApps as $possibleApp) {
+                $version = self::getAppVersionByPath($possibleApp['path']);
+                if (empty($versionToLoad) || version_compare($version, $versionToLoad['version'], '>')) {
+                    $versionToLoad = array(
+                        'dir' => $possibleApp,
+                        'version' => $version,
+                    );
+                }
+            }
+            $app_dir[$appId] = $versionToLoad['dir'];
+            return $versionToLoad['dir'];
+            //TODO - write test
+        }
+    }
+
+    /**
+     * Get the directory for the given app.
+     * If the app is defined in multiple directories, the first one is taken. (false if not found)
+     *
+     * @param string $appId
+     * @return string|false
+     */
+    public static function getAppPath($appId) {
+        if ($appId === null || trim($appId) === '') {
+            return false;
+        }
+
+        if (($dir = self::findAppInDirectories($appId)) != false) {
+            return $dir['path'] . '/' . $appId;
+        }
+        return false;
+    }
+
+    /**
+     * Get the path for the given app on the access
+     * If the app is defined in multiple directories, the first one is taken. (false if not found)
+     *
+     * @param string $appId
+     * @return string|false
+     */
+    public static function getAppWebPath($appId) {
+        if (($dir = self::findAppInDirectories($appId)) != false) {
+            return OC::$WEBROOT . $dir['url'] . '/' . $appId;
+        }
+        return false;
+    }
+
+    /**
+     * get the last version of the app from appinfo/info.xml
+     *
+     * @param string $appId
+     * @param bool $useCache
+     * @return string
+     */
+    public static function getAppVersion($appId, $useCache = true) {
+        if($useCache && isset(self::$appVersion[$appId])) {
+            return self::$appVersion[$appId];
+        }
+
+        $file = self::getAppPath($appId);
+        self::$appVersion[$appId] = ($file !== false) ? self::getAppVersionByPath($file) : '0';
+        return self::$appVersion[$appId];
+    }
+
+    /**
+     * get app's version based on it's path
+     *
+     * @param string $path
+     * @return string
+     */
+    public static function getAppVersionByPath($path) {
+        $infoFile = $path . '/appinfo/info.xml';
+        $appData = self::getAppInfo($infoFile, true);
+        return isset($appData['version']) ? $appData['version'] : '';
+    }
+
+
+    /**
+     * Read all app metadata from the info.xml file
+     *
+     * @param string $appId id of the app or the path of the info.xml file
+     * @param bool $path
+     * @param string $lang
+     * @return array|null
+     * @note all data is read from info.xml, not just pre-defined fields
+     */
+    public static function getAppInfo($appId, $path = false, $lang = null) {
+        if ($path) {
+            $file = $appId;
+        } else {
+            if ($lang === null && isset(self::$appInfo[$appId])) {
+                return self::$appInfo[$appId];
+            }
+            $appPath = self::getAppPath($appId);
+            if($appPath === false) {
+                return null;
+            }
+            $file = $appPath . '/appinfo/info.xml';
+        }
+
+        $parser = new InfoParser(\OC::$server->getMemCacheFactory()->createLocal('core.appinfo'));
+        $data = $parser->parse($file);
+
+        if (is_array($data)) {
+            $data = OC_App::parseAppInfo($data, $lang);
+        }
+        if(isset($data['ocsid'])) {
+            $storedId = \OC::$server->getConfig()->getAppValue($appId, 'ocsid');
+            if($storedId !== '' && $storedId !== $data['ocsid']) {
+                $data['ocsid'] = $storedId;
+            }
+        }
+
+        if ($lang === null) {
+            self::$appInfo[$appId] = $data;
+        }
+
+        return $data;
+    }
+
+    /**
+     * Returns the navigation
+     *
+     * @return array
+     *
+     * This function returns an array containing all entries added. The
+     * entries are sorted by the key 'order' ascending. Additional to the keys
+     * given for each app the following keys exist:
+     *   - active: boolean, signals if the user is on this navigation entry
+     */
+    public static function getNavigation() {
+        $entries = OC::$server->getNavigationManager()->getAll();
+        return self::proceedNavigation($entries);
+    }
+
+    /**
+     * Returns the Settings Navigation
+     *
+     * @return string[]
+     *
+     * This function returns an array containing all settings pages added. The
+     * entries are sorted by the key 'order' ascending.
+     */
+    public static function getSettingsNavigation() {
+        $entries = OC::$server->getNavigationManager()->getAll('settings');
+        return self::proceedNavigation($entries);
+    }
+
+    /**
+     * get the id of loaded app
+     *
+     * @return string
+     */
+    public static function getCurrentApp() {
+        $request = \OC::$server->getRequest();
+        $script = substr($request->getScriptName(), strlen(OC::$WEBROOT) + 1);
+        $topFolder = substr($script, 0, strpos($script, '/'));
+        if (empty($topFolder)) {
+            $path_info = $request->getPathInfo();
+            if ($path_info) {
+                $topFolder = substr($path_info, 1, strpos($path_info, '/', 1) - 1);
+            }
+        }
+        if ($topFolder == 'apps') {
+            $length = strlen($topFolder);
+            return substr($script, $length + 1, strpos($script, '/', $length + 1) - $length - 1);
+        } else {
+            return $topFolder;
+        }
+    }
+
+    /**
+     * @param string $type
+     * @return array
+     */
+    public static function getForms($type) {
+        $forms = array();
+        switch ($type) {
+            case 'admin':
+                $source = self::$adminForms;
+                break;
+            case 'personal':
+                $source = self::$personalForms;
+                break;
+            default:
+                return array();
+        }
+        foreach ($source as $form) {
+            $forms[] = include $form;
+        }
+        return $forms;
+    }
+
+    /**
+     * register an admin form to be shown
+     *
+     * @param string $app
+     * @param string $page
+     */
+    public static function registerAdmin($app, $page) {
+        self::$adminForms[] = $app . '/' . $page . '.php';
+    }
+
+    /**
+     * register a personal form to be shown
+     * @param string $app
+     * @param string $page
+     */
+    public static function registerPersonal($app, $page) {
+        self::$personalForms[] = $app . '/' . $page . '.php';
+    }
+
+    /**
+     * @param array $entry
+     */
+    public static function registerLogIn(array $entry) {
+        self::$altLogin[] = $entry;
+    }
+
+    /**
+     * @return array
+     */
+    public static function getAlternativeLogIns() {
+        return self::$altLogin;
+    }
+
+    /**
+     * get a list of all apps in the apps folder
+     *
+     * @return array an array of app names (string IDs)
+     * @todo: change the name of this method to getInstalledApps, which is more accurate
+     */
+    public static function getAllApps() {
+
+        $apps = array();
+
+        foreach (OC::$APPSROOTS as $apps_dir) {
+            if (!is_readable($apps_dir['path'])) {
+                \OCP\Util::writeLog('core', 'unable to read app folder : ' . $apps_dir['path'], \OCP\Util::WARN);
+                continue;
+            }
+            $dh = opendir($apps_dir['path']);
+
+            if (is_resource($dh)) {
+                while (($file = readdir($dh)) !== false) {
+
+                    if ($file[0] != '.' and is_dir($apps_dir['path'] . '/' . $file) and is_file($apps_dir['path'] . '/' . $file . '/appinfo/info.xml')) {
+
+                        $apps[] = $file;
+                    }
+                }
+            }
+        }
+
+        $apps = array_unique($apps);
+
+        return $apps;
+    }
+
+    /**
+     * List all apps, this is used in apps.php
+     *
+     * @return array
+     */
+    public function listAllApps() {
+        $installedApps = OC_App::getAllApps();
+
+        $appManager = \OC::$server->getAppManager();
+        //we don't want to show configuration for these
+        $blacklist = $appManager->getAlwaysEnabledApps();
+        $appList = array();
+        $langCode = \OC::$server->getL10N('core')->getLanguageCode();
+        $urlGenerator = \OC::$server->getURLGenerator();
+
+        foreach ($installedApps as $app) {
+            if (array_search($app, $blacklist) === false) {
+
+                $info = OC_App::getAppInfo($app, false, $langCode);
+                if (!is_array($info)) {
+                    \OCP\Util::writeLog('core', 'Could not read app info file for app "' . $app . '"', \OCP\Util::ERROR);
+                    continue;
+                }
+
+                if (!isset($info['name'])) {
+                    \OCP\Util::writeLog('core', 'App id "' . $app . '" has no name in appinfo', \OCP\Util::ERROR);
+                    continue;
+                }
+
+                $enabled = \OC::$server->getAppConfig()->getValue($app, 'enabled', 'no');
+                $info['groups'] = null;
+                if ($enabled === 'yes') {
+                    $active = true;
+                } else if ($enabled === 'no') {
+                    $active = false;
+                } else {
+                    $active = true;
+                    $info['groups'] = $enabled;
+                }
+
+                $info['active'] = $active;
+
+                if ($appManager->isShipped($app)) {
+                    $info['internal'] = true;
+                    $info['level'] = self::officialApp;
+                    $info['removable'] = false;
+                } else {
+                    $info['internal'] = false;
+                    $info['removable'] = true;
+                }
+
+                $appPath = self::getAppPath($app);
+                if($appPath !== false) {
+                    $appIcon = $appPath . '/img/' . $app . '.svg';
+                    if (file_exists($appIcon)) {
+                        $info['preview'] = $urlGenerator->imagePath($app, $app . '.svg');
+                        $info['previewAsIcon'] = true;
+                    } else {
+                        $appIcon = $appPath . '/img/app.svg';
+                        if (file_exists($appIcon)) {
+                            $info['preview'] = $urlGenerator->imagePath($app, 'app.svg');
+                            $info['previewAsIcon'] = true;
+                        }
+                    }
+                }
+                // fix documentation
+                if (isset($info['documentation']) && is_array($info['documentation'])) {
+                    foreach ($info['documentation'] as $key => $url) {
+                        // If it is not an absolute URL we assume it is a key
+                        // i.e. admin-ldap will get converted to go.php?to=admin-ldap
+                        if (stripos($url, 'https://') !== 0 && stripos($url, 'http://') !== 0) {
+                            $url = $urlGenerator->linkToDocs($url);
+                        }
+
+                        $info['documentation'][$key] = $url;
+                    }
+                }
+
+                $info['version'] = OC_App::getAppVersion($app);
+                $appList[] = $info;
+            }
+        }
+
+        return $appList;
+    }
+
+    /**
+     * Returns the internal app ID or false
+     * @param string $ocsID
+     * @return string|false
+     */
+    public static function getInternalAppIdByOcs($ocsID) {
+        if(is_numeric($ocsID)) {
+            $idArray = \OC::$server->getAppConfig()->getValues(false, 'ocsid');
+            if(array_search($ocsID, $idArray)) {
+                return array_search($ocsID, $idArray);
+            }
+        }
+        return false;
+    }
+
+    public static function shouldUpgrade($app) {
+        $versions = self::getAppVersions();
+        $currentVersion = OC_App::getAppVersion($app);
+        if ($currentVersion && isset($versions[$app])) {
+            $installedVersion = $versions[$app];
+            if (!version_compare($currentVersion, $installedVersion, '=')) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    /**
+     * Adjust the number of version parts of $version1 to match
+     * the number of version parts of $version2.
+     *
+     * @param string $version1 version to adjust
+     * @param string $version2 version to take the number of parts from
+     * @return string shortened $version1
+     */
+    private static function adjustVersionParts($version1, $version2) {
+        $version1 = explode('.', $version1);
+        $version2 = explode('.', $version2);
+        // reduce $version1 to match the number of parts in $version2
+        while (count($version1) > count($version2)) {
+            array_pop($version1);
+        }
+        // if $version1 does not have enough parts, add some
+        while (count($version1) < count($version2)) {
+            $version1[] = '0';
+        }
+        return implode('.', $version1);
+    }
+
+    /**
+     * Check whether the current ownCloud version matches the given
+     * application's version requirements.
+     *
+     * The comparison is made based on the number of parts that the
+     * app info version has. For example for ownCloud 6.0.3 if the
+     * app info version is expecting version 6.0, the comparison is
+     * made on the first two parts of the ownCloud version.
+     * This means that it's possible to specify "requiremin" => 6
+     * and "requiremax" => 6 and it will still match ownCloud 6.0.3.
+     *
+     * @param string $ocVersion ownCloud version to check against
+     * @param array $appInfo app info (from xml)
+     *
+     * @return boolean true if compatible, otherwise false
+     */
+    public static function isAppCompatible($ocVersion, $appInfo) {
+        $requireMin = '';
+        $requireMax = '';
+        if (isset($appInfo['dependencies']['nextcloud']['@attributes']['min-version'])) {
+            $requireMin = $appInfo['dependencies']['nextcloud']['@attributes']['min-version'];
+        } elseif (isset($appInfo['dependencies']['owncloud']['@attributes']['min-version'])) {
+            $requireMin = $appInfo['dependencies']['owncloud']['@attributes']['min-version'];
+        } else if (isset($appInfo['requiremin'])) {
+            $requireMin = $appInfo['requiremin'];
+        } else if (isset($appInfo['require'])) {
+            $requireMin = $appInfo['require'];
+        }
+
+        if (isset($appInfo['dependencies']['nextcloud']['@attributes']['max-version'])) {
+            $requireMax = $appInfo['dependencies']['nextcloud']['@attributes']['max-version'];
+        } elseif (isset($appInfo['dependencies']['owncloud']['@attributes']['max-version'])) {
+            $requireMax = $appInfo['dependencies']['owncloud']['@attributes']['max-version'];
+        } else if (isset($appInfo['requiremax'])) {
+            $requireMax = $appInfo['requiremax'];
+        }
+
+        if (is_array($ocVersion)) {
+            $ocVersion = implode('.', $ocVersion);
+        }
+
+        if (!empty($requireMin)
+            && version_compare(self::adjustVersionParts($ocVersion, $requireMin), $requireMin, '<')
+        ) {
+
+            return false;
+        }
+
+        if (!empty($requireMax)
+            && version_compare(self::adjustVersionParts($ocVersion, $requireMax), $requireMax, '>')
+        ) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * get the installed version of all apps
+     */
+    public static function getAppVersions() {
+        static $versions;
+
+        if(!$versions) {
+            $appConfig = \OC::$server->getAppConfig();
+            $versions = $appConfig->getValues(false, 'installed_version');
+        }
+        return $versions;
+    }
+
+    /**
+     * @param string $app
+     * @param \OCP\IConfig $config
+     * @param \OCP\IL10N $l
+     * @return bool
+     *
+     * @throws Exception if app is not compatible with this version of ownCloud
+     * @throws Exception if no app-name was specified
+     */
+    public function installApp($app,
+                                \OCP\IConfig $config,
+                                \OCP\IL10N $l) {
+        if ($app !== false) {
+            // check if the app is compatible with this version of ownCloud
+            $info = self::getAppInfo($app);
+            if(!is_array($info)) {
+                throw new \Exception(
+                    $l->t('App "%s" cannot be installed because appinfo file cannot be read.',
+                        [$info['name']]
+                    )
+                );
+            }
+
+            $version = \OCP\Util::getVersion();
+            if (!self::isAppCompatible($version, $info)) {
+                throw new \Exception(
+                    $l->t('App "%s" cannot be installed because it is not compatible with this version of the server.',
+                        array($info['name'])
+                    )
+                );
+            }
+
+            // check for required dependencies
+            self::checkAppDependencies($config, $l, $info);
+
+            $config->setAppValue($app, 'enabled', 'yes');
+            if (isset($appData['id'])) {
+                $config->setAppValue($app, 'ocsid', $appData['id']);
+            }
+
+            if(isset($info['settings']) && is_array($info['settings'])) {
+                $appPath = self::getAppPath($app);
+                self::registerAutoloading($app, $appPath);
+                \OC::$server->getSettingsManager()->setupSettings($info['settings']);
+            }
+
+            \OC_Hook::emit('OC_App', 'post_enable', array('app' => $app));
+        } else {
+            if(empty($appName) ) {
+                throw new \Exception($l->t("No app name specified"));
+            } else {
+                throw new \Exception($l->t("App '%s' could not be installed!", $appName));
+            }
+        }
+
+        return $app;
+    }
+
+    /**
+     * update the database for the app and call the update script
+     *
+     * @param string $appId
+     * @return bool
+     */
+    public static function updateApp($appId) {
+        $appPath = self::getAppPath($appId);
+        if($appPath === false) {
+            return false;
+        }
+        self::registerAutoloading($appId, $appPath);
+
+        $appData = self::getAppInfo($appId);
+        self::executeRepairSteps($appId, $appData['repair-steps']['pre-migration']);
+
+        if (file_exists($appPath . '/appinfo/database.xml')) {
+            OC_DB::updateDbFromStructure($appPath . '/appinfo/database.xml');
+        } else {
+            $ms = new MigrationService($appId, \OC::$server->getDatabaseConnection());
+            $ms->migrate();
+        }
+
+        self::executeRepairSteps($appId, $appData['repair-steps']['post-migration']);
+        self::setupLiveMigrations($appId, $appData['repair-steps']['live-migration']);
+        unset(self::$appVersion[$appId]);
+
+        // run upgrade code
+        if (file_exists($appPath . '/appinfo/update.php')) {
+            self::loadApp($appId);
+            include $appPath . '/appinfo/update.php';
+        }
+        self::setupBackgroundJobs($appData['background-jobs']);
+        if(isset($appData['settings']) && is_array($appData['settings'])) {
+            \OC::$server->getSettingsManager()->setupSettings($appData['settings']);
+        }
+
+        //set remote/public handlers
+        if (array_key_exists('ocsid', $appData)) {
+            \OC::$server->getConfig()->setAppValue($appId, 'ocsid', $appData['ocsid']);
+        } elseif(\OC::$server->getConfig()->getAppValue($appId, 'ocsid', null) !== null) {
+            \OC::$server->getConfig()->deleteAppValue($appId, 'ocsid');
+        }
+        foreach ($appData['remote'] as $name => $path) {
+            \OC::$server->getConfig()->setAppValue('core', 'remote_' . $name, $appId . '/' . $path);
+        }
+        foreach ($appData['public'] as $name => $path) {
+            \OC::$server->getConfig()->setAppValue('core', 'public_' . $name, $appId . '/' . $path);
+        }
+
+        self::setAppTypes($appId);
+
+        $version = \OC_App::getAppVersion($appId);
+        \OC::$server->getAppConfig()->setValue($appId, 'installed_version', $version);
+
+        \OC::$server->getEventDispatcher()->dispatch(ManagerEvent::EVENT_APP_UPDATE, new ManagerEvent(
+            ManagerEvent::EVENT_APP_UPDATE, $appId
+        ));
+
+        return true;
+    }
+
+    /**
+     * @param string $appId
+     * @param string[] $steps
+     * @throws \OC\NeedsUpdateException
+     */
+    public static function executeRepairSteps($appId, array $steps) {
+        if (empty($steps)) {
+            return;
+        }
+        // load the app
+        self::loadApp($appId);
+
+        $dispatcher = OC::$server->getEventDispatcher();
+
+        // load the steps
+        $r = new Repair([], $dispatcher);
+        foreach ($steps as $step) {
+            try {
+                $r->addStep($step);
+            } catch (Exception $ex) {
+                $r->emit('\OC\Repair', 'error', [$ex->getMessage()]);
+                \OC::$server->getLogger()->logException($ex);
+            }
+        }
+        // run the steps
+        $r->run();
+    }
+
+    public static function setupBackgroundJobs(array $jobs) {
+        $queue = \OC::$server->getJobList();
+        foreach ($jobs as $job) {
+            $queue->add($job);
+        }
+    }
+
+    /**
+     * @param string $appId
+     * @param string[] $steps
+     */
+    private static function setupLiveMigrations($appId, array $steps) {
+        $queue = \OC::$server->getJobList();
+        foreach ($steps as $step) {
+            $queue->add('OC\Migration\BackgroundRepair', [
+                'app' => $appId,
+                'step' => $step]);
+        }
+    }
+
+    /**
+     * @param string $appId
+     * @return \OC\Files\View|false
+     */
+    public static function getStorage($appId) {
+        if (\OC::$server->getAppManager()->isEnabledForUser($appId)) { //sanity check
+            if (\OC::$server->getUserSession()->isLoggedIn()) {
+                $view = new \OC\Files\View('/' . OC_User::getUser());
+                if (!$view->file_exists($appId)) {
+                    $view->mkdir($appId);
+                }
+                return new \OC\Files\View('/' . OC_User::getUser() . '/' . $appId);
+            } else {
+                \OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ', user not logged in', \OCP\Util::ERROR);
+                return false;
+            }
+        } else {
+            \OCP\Util::writeLog('core', 'Can\'t get app storage, app ' . $appId . ' not enabled', \OCP\Util::ERROR);
+            return false;
+        }
+    }
+
+    protected static function findBestL10NOption($options, $lang) {
+        $fallback = $similarLangFallback = $englishFallback = false;
+
+        $lang = strtolower($lang);
+        $similarLang = $lang;
+        if (strpos($similarLang, '_')) {
+            // For "de_DE" we want to find "de" and the other way around
+            $similarLang = substr($lang, 0, strpos($lang, '_'));
+        }
+
+        foreach ($options as $option) {
+            if (is_array($option)) {
+                if ($fallback === false) {
+                    $fallback = $option['@value'];
+                }
+
+                if (!isset($option['@attributes']['lang'])) {
+                    continue;
+                }
+
+                $attributeLang = strtolower($option['@attributes']['lang']);
+                if ($attributeLang === $lang) {
+                    return $option['@value'];
+                }
+
+                if ($attributeLang === $similarLang) {
+                    $similarLangFallback = $option['@value'];
+                } else if (strpos($attributeLang, $similarLang . '_') === 0) {
+                    if ($similarLangFallback === false) {
+                        $similarLangFallback =  $option['@value'];
+                    }
+                }
+            } else {
+                $englishFallback = $option;
+            }
+        }
+
+        if ($similarLangFallback !== false) {
+            return $similarLangFallback;
+        } else if ($englishFallback !== false) {
+            return $englishFallback;
+        }
+        return (string) $fallback;
+    }
+
+    /**
+     * parses the app data array and enhanced the 'description' value
+     *
+     * @param array $data the app data
+     * @param string $lang
+     * @return array improved app data
+     */
+    public static function parseAppInfo(array $data, $lang = null) {
+
+        if ($lang && isset($data['name']) && is_array($data['name'])) {
+            $data['name'] = self::findBestL10NOption($data['name'], $lang);
+        }
+        if ($lang && isset($data['summary']) && is_array($data['summary'])) {
+            $data['summary'] = self::findBestL10NOption($data['summary'], $lang);
+        }
+        if ($lang && isset($data['description']) && is_array($data['description'])) {
+            $data['description'] = trim(self::findBestL10NOption($data['description'], $lang));
+        } else if (isset($data['description']) && is_string($data['description'])) {
+            $data['description'] = trim($data['description']);
+        } else  {
+            $data['description'] = '';
+        }
+
+        return $data;
+    }
+
+    /**
+     * @param \OCP\IConfig $config
+     * @param \OCP\IL10N $l
+     * @param array $info
+     * @throws \Exception
+     */
+    public static function checkAppDependencies($config, $l, $info) {
+        $dependencyAnalyzer = new DependencyAnalyzer(new Platform($config), $l);
+        $missing = $dependencyAnalyzer->analyze($info);
+        if (!empty($missing)) {
+            $missingMsg = implode(PHP_EOL, $missing);
+            throw new \Exception(
+                $l->t('App "%s" cannot be installed because the following dependencies are not fulfilled: %s',
+                    [$info['name'], $missingMsg]
+                )
+            );
+        }
+    }
 }