AppInfo: add config checks before using backends

Config checks were removed when moving to IBootstrap:
f6bcde7 (Move to IBootstrap initialization and remove the deprecated appinfo/app.php, 2025-04-10)

Due to the missing checks, the Nextcloud log is flooded with error messages (SQL errors) if
the configuration is incomplete. This is also if either only the user or group backend is used.

README.md

@@ -63,7 +63,7 @@ Name | Description | Details
 **Email sync** | Sync e-mail address with the Nextcloud.<br/>- *None* - Disables this feature. This is the default option.<br/>- *Synchronise only once* - Copy the e-mail address to the Nextcloud preferences if its not set.<br/>- *Nextcloud always wins* - Always copy the e-mail address to the database. This updates the user table.<br/>- *SQL always wins* - Always copy the e-mail address to the Nextcloud preferences. | Optional.<br/>Default: *None*.<br/>Requires: user *Email* column.
 **Quota sync** | Sync user quota with the Nextcloud.<br/>- *None* - Disables this feature. This is the default option.<br/>- *Synchronise only once* - Copy the user quota to the Nextcloud preferences if its not set.<br/>- *Nextcloud always wins* - Always copy the user quota to the database. This updates the user table.<br/>- *SQL always wins* - Always copy the user quota to the Nextcloud preferences. | Optional.<br/>Default: *None*.<br/>Requires: user *Quota* column.
 **Home mode** | User storage path.<br/>- *Default* - Let the Nextcloud manage this. The default option.<br/>- *Query* - Use location from the user table pointed by the *home* column.<br/>- *Static* - Use static location pointed by the *Home Location* option. | Optional<br/>Default: *Default*.
-**Home location** | User storage path for the `Static` *Home mode*. The `%u` variable is replaced with the username of the user. | Mandatory if the *Home mode* is set to `Static`.
+**Home location** | User storage path for the `Static` *Home mode*. The `%u` variable is replaced with the uid of the user. | Mandatory if the *Home mode* is set to `Static`.
 **Default group** | Default group for all 'User SQL' users. | Optional.
 
 #### User table
@@ -74,7 +74,7 @@ Name | Description | Details
 --- | --- | ---
 **Table name** | The table name. | Mandatory for user backend.
 **UID** | User ID column. | Mandatory for user backend.
-**Username** | Username column. | Optional.
+**Username** | Username column which is used **only** for password verification. | Optional. If unsure leave it blank and use only the `uid` column.
 **Email** | E-mail column. | Mandatory for *Email sync* option.
 **Quota** | Quota column. | Mandatory for *Quota sync* option.
 **Home** | Home path column. | Mandatory for `Query` *Home sync* option.
@@ -120,12 +120,15 @@ For all options to work three tables are required:
 If you already have an existing database you can always create database views which fits this model,
 but be aware that some functionalities requires data changes (update queries).
 
-If you don't have any database model yet you can use below tables (MySQL):
+If you don't have any database model yet you can use below tables
+(MySQL). Please note that the optional `username` above really is only
+used for password matching and defaults to be equal to the `uid`
+column. You also may want to compare with the `oc_users` and
+`oc_groups` table from you Nextcloud instance.
 ```
 CREATE TABLE sql_user
 (
-  uid            INT         PRIMARY KEY AUTO_INCREMENT,
-  username       VARCHAR(16) NOT NULL UNIQUE,
+  uid            VARCHAR(64) PRIMARY KEY,
   display_name   TEXT        NULL,
   email          TEXT        NULL,
   quota          TEXT        NULL,
@@ -139,15 +142,15 @@ CREATE TABLE sql_user
 
 CREATE TABLE sql_group
 (
-  gid   INT         PRIMARY KEY AUTO_INCREMENT,
-  name  VARCHAR(16) NOT NULL UNIQUE,
+  gid   VARCHAR(64)  PRIMARY KEY,
+  name  VARCHAR(255) NOT NULL,
   admin BOOLEAN      NOT NULL DEFAULT FALSE
 );
 
 CREATE TABLE sql_user_group
 (
-  uid INT NOT NULL,
-  gid INT NOT NULL,
+  uid   VARCHAR(64),
+  gid   VARCHAR(64),
   PRIMARY KEY (uid, gid),
   FOREIGN KEY (uid) REFERENCES sql_user (uid),
   FOREIGN KEY (gid) REFERENCES sql_group (gid),

appinfo/app.php

@@ -1,31 +0,0 @@
-<?php
-/**
- * Nextcloud - user_sql
- *
- * @copyright 2012-2015 Andreas Böhler <dev (at) aboehler (dot) at>
- * @copyright 2018 Marcin Łojewski <dev@mlojewski.me>
- * @author    Marcin Łojewski <dev@mlojewski.me>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program.  If not, see <https://www.gnu.org/licenses/>.
- */
-
-use OCA\UserSQL\AppInfo\Application;
-use OCP\AppFramework\QueryException;
-
-try {
-    $app = new Application();
-    $app->registerBackends();
-} catch (QueryException $queryException) {
-    OC::$server->getLogger()->logException($queryException);
-}

appinfo/info.xml

@@ -21,8 +21,8 @@
     </types>
     <category>auth</category>
     <dependencies>
-        <php min-version="7.1"/>
-        <nextcloud min-version="21" max-version="23"/>
+        <php min-version="8.0"/>
+        <nextcloud min-version="31" max-version="31"/>
     </dependencies>
     <settings>
         <admin>\OCA\UserSQL\Settings\Admin</admin>

lib/Action/EmailSync.php

@@ -27,7 +27,7 @@ use OCA\UserSQL\Model\User;
 use OCA\UserSQL\Properties;
 use OCA\UserSQL\Repository\UserRepository;
 use OCP\IConfig;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 
 /**
  * Synchronizes the user email address.
@@ -41,7 +41,7 @@ class EmailSync implements IUserAction
      */
     private $appName;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -61,13 +61,13 @@ class EmailSync implements IUserAction
      * The default constructor.
      *
      * @param string         $appName        The application name.
-     * @param ILogger        $logger         The logger instance.
+     * @param LoggerInterface        $logger         The logger instance.
      * @param Properties     $properties     The properties array.
      * @param IConfig        $config         The config instance.
      * @param UserRepository $userRepository The user repository.
      */
     public function __construct(
-        $appName, ILogger $logger, Properties $properties, IConfig $config,
+        $appName, LoggerInterface $logger, Properties $properties, IConfig $config,
         UserRepository $userRepository
     ) {
         $this->appName = $appName;
@@ -87,6 +87,11 @@ class EmailSync implements IUserAction
             "Entering EmailSync#doAction($user->uid)", ["app" => $this->appName]
         );
 
+		// enforce lowercase
+		if (!empty($user->email)) {
+			$user->email = strtolower($user->email);
+		}
+
         $ncMail = $this->config->getUserValue(
             $user->uid, "settings", "email", ""
         );
@@ -117,7 +122,7 @@ class EmailSync implements IUserAction
 
             break;
         case App::SYNC_FORCE_SQL:
-            if (!empty($user->email) && $user->email !== $ncMail) {
+            if (!empty($user->email) && $user->email !== strtolower($ncMail)) {
                 $this->config->setUserValue(
                     $user->uid, "settings", "email", $user->email
                 );

lib/Action/NameSync.php

@@ -27,7 +27,7 @@ use OCA\UserSQL\Model\User;
 use OCA\UserSQL\Properties;
 use OCA\UserSQL\Repository\UserRepository;
 use OCP\IConfig;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 
 /**
  * Synchronizes the user name.
@@ -41,7 +41,7 @@ class NameSync implements IUserAction
      */
     private $appName;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -61,13 +61,13 @@ class NameSync implements IUserAction
      * The default constructor.
      *
      * @param string         $appName        The application name.
-     * @param ILogger        $logger         The logger instance.
+     * @param LoggerInterface        $logger         The logger instance.
      * @param Properties     $properties     The properties array.
      * @param IConfig        $config         The config instance.
      * @param UserRepository $userRepository The user repository.
      */
     public function __construct(
-        $appName, ILogger $logger, Properties $properties, IConfig $config,
+        $appName, LoggerInterface $logger, Properties $properties, IConfig $config,
         UserRepository $userRepository
     ) {
         $this->appName = $appName;

lib/Action/QuotaSync.php

@@ -27,7 +27,7 @@ use OCA\UserSQL\Model\User;
 use OCA\UserSQL\Properties;
 use OCA\UserSQL\Repository\UserRepository;
 use OCP\IConfig;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 
 /**
  * Synchronizes the user quota.
@@ -41,7 +41,7 @@ class QuotaSync implements IUserAction
      */
     private $appName;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -61,13 +61,13 @@ class QuotaSync implements IUserAction
      * The default constructor.
      *
      * @param string         $appName        The application name.
-     * @param ILogger        $logger         The logger instance.
+     * @param LoggerInterface        $logger         The logger instance.
      * @param Properties     $properties     The properties array.
      * @param IConfig        $config         The config instance.
      * @param UserRepository $userRepository The user repository.
      */
     public function __construct(
-        $appName, ILogger $logger, Properties $properties, IConfig $config,
+        $appName, LoggerInterface $logger, Properties $properties, IConfig $config,
         UserRepository $userRepository
     ) {
         $this->appName = $appName;

lib/AppInfo/Application.php

@@ -4,6 +4,8 @@
  *
  * @copyright 2018 Marcin Łojewski <dev@mlojewski.me>
  * @author    Marcin Łojewski <dev@mlojewski.me>
+ * @copyright 2025 Claus-Justus Heine <himself@claus-justus-heine.de>
+ * @author    Claus-Justus Heine <himself@claus-justus-heine.de>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -22,14 +24,20 @@
 namespace OCA\UserSQL\AppInfo;
 
 use OCP\AppFramework\App;
-use OCP\AppFramework\QueryException;
+use OCP\AppFramework\Bootstrap\IBootContext;
+use OCP\AppFramework\Bootstrap\IBootstrap;
+use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\IGroupManager;
+use OCP\IUserManager;
+
+use OCA\UserSQL\Backend;
 
 /**
  * The application bootstrap class.
  *
  * @author Marcin Łojewski <dev@mlojewski.me>
  */
-class Application extends App
+class Application extends App implements IBootstrap
 {
     /**
      * The class constructor.
@@ -42,26 +50,25 @@ class Application extends App
         parent::__construct("user_sql", $urlParams);
     }
 
-    /**
-     * Register the application backends
-     * if all necessary configuration is provided.
-     *
-     * @throws QueryException If the query container's could not be resolved
-     */
-    public function registerBackends()
-    {
-        $userBackend = $this->getContainer()->query(
-            '\OCA\UserSQL\Backend\UserBackend'
-        );
-        $groupBackend = $this->getContainer()->query(
-            '\OCA\UserSQL\Backend\GroupBackend'
-        );
+	/** {@inheritdoc} */
+	public function register(IRegistrationContext $context): void
+	{}
 
+	/** {@inheritdoc} */
+	public function boot(IBootContext $context): void
+	{
+		$context->injectFn(function(
+			IUserManager $userManager,
+			Backend\UserBackend $userBackend,
+			IGroupManager $groupManager,
+			Backend\GroupBackend $groupBackend,
+		) {
 			if ($userBackend->isConfigured()) {
-            \OC::$server->getUserManager()->registerBackend($userBackend);
+				$userManager->registerBackend($userBackend);
 			}
 			if ($groupBackend->isConfigured()) {
-            \OC::$server->getGroupManager()->addBackend($groupBackend);
-        }
+				$groupManager->addBackend($groupBackend);
+			}
+		});
 	}
 }

lib/Backend/GroupBackend.php

@@ -3,6 +3,7 @@
  * Nextcloud - user_sql
  *
  * @copyright 2018 Marcin Łojewski <dev@mlojewski.me>
+ * @copyright 2022-2025 Claus-Justus Heine <himself@claus-justus-heine.de>
  * @author    Marcin Łojewski <dev@mlojewski.me>
  *
  * This program is free software: you can redistribute it and/or modify
@@ -31,7 +32,12 @@ use OCP\Group\Backend\ABackend;
 use OCP\Group\Backend\ICountUsersBackend;
 use OCP\Group\Backend\IGroupDetailsBackend;
 use OCP\Group\Backend\IIsAdminBackend;
-use OCP\ILogger;
+use OCP\Group\Backend\ISearchableGroupBackend;
+use OCP\Group\Backend\INamedBackedn;
+use Psr\Log\LoggerInterface;
+use OCP\IUserManager;
+
+use OC\User\LazyUser;
 
 /**
  * The SQL group backend manager.
@@ -41,7 +47,8 @@ use OCP\ILogger;
 final class GroupBackend extends ABackend implements
     ICountUsersBackend,
     IGroupDetailsBackend,
-    IIsAdminBackend
+    IIsAdminBackend,
+	ISearchableGroupBackend
 {
     const USER_SQL_GID = "user_sql";
 
@@ -50,7 +57,7 @@ final class GroupBackend extends ABackend implements
      */
     private $appName;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -71,12 +78,12 @@ final class GroupBackend extends ABackend implements
      *
      * @param string          $AppName         The application name.
      * @param Cache           $cache           The cache instance.
-     * @param ILogger         $logger          The logger instance.
+     * @param LoggerInterface         $logger          The logger instance.
      * @param Properties      $properties      The properties array.
      * @param GroupRepository $groupRepository The group repository.
      */
     public function __construct(
-        $AppName, Cache $cache, ILogger $logger, Properties $properties,
+        $AppName, Cache $cache, LoggerInterface $logger, Properties $properties,
         GroupRepository $groupRepository
     ) {
         $this->appName = $AppName;
@@ -88,6 +95,14 @@ final class GroupBackend extends ABackend implements
 
 	/**
      * @inheritdoc
+     */
+	public function getBackendName(): string
+	{
+        return "User SQL";
+	}
+
+	/**
+     * @inheritdoc
      */
     public function getGroups($search = "", $limit = null, $offset = null)
     {
@@ -354,16 +369,16 @@ final class GroupBackend extends ABackend implements
             ["app" => $this->appName]
         );
 
-        $cacheKey = self::class . "group_users_" . $gid . "_" . $search . "_"
+        $cacheKey = self::class . "group_uids_" . $gid . "_" . $search . "_"
             . $limit . "_" . $offset;
-        $users = $this->cache->get($cacheKey);
+        $uids = $this->cache->get($cacheKey);
 
-        if (!is_null($users)) {
+        if (!is_null($uids)) {
             $this->logger->debug(
                 "Returning from cache usersInGroup($gid, $search, $limit, $offset): count("
-                . count($users) . ")", ["app" => $this->appName]
+                . count($uids) . ")", ["app" => $this->appName]
             );
-            return $users;
+            return $uids;
         }
 
         $uids = $this->groupRepository->findAllUidsBySearchTerm(
@@ -386,7 +401,51 @@ final class GroupBackend extends ABackend implements
 	/**
      * @inheritdoc
      */
-    public function isAdmin(string $uid = null): bool
+	public function searchInGroup(string $gid, string $search = '', int $limit = -1, int $offset = 0): array
+	{
+		$this->logger->debug(
+            "Entering searchInGroup($gid, $search, $limit, $offset)",
+            ["app" => $this->appName]
+        );
+
+        $cacheKey = self::class . "group_users_" . $gid . "_" . $search . "_"
+            . $limit . "_" . $offset;
+        $names = $this->cache->get($cacheKey);
+
+        if ($names === null) {
+			$names = $this->groupRepository->findAllUsersBySearchTerm(
+				$this->substituteGid($gid), "%" . $search . "%", $limit, $offset
+			);
+
+			if ($names === false) {
+				return [];
+			}
+
+			$this->cache->set($cacheKey, $names);
+			$this->logger->debug(
+				"Using from DB searchInGroup($gid, $search, $limit, $offset): count("
+					. count($names) . ")", ["app" => $this->appName]
+			);
+		} else {
+            $this->logger->debug(
+                "Using from cache searchInGroup($gid, $search, $limit, $offset): count("
+					. count($names) . ")", ["app" => $this->appName]
+            );
+        }
+
+		$users = [];
+		$userManager = \OCP\Server::get(IUserManager::class);
+		foreach ($names as $uid => $name) {
+			$users[$uid] = new LazyUser($uid, $userManager, $name);
+		}
+
+		return $users;
+	}
+
+    /**
+     * @inheritdoc
+     */
+    public function isAdmin(?string $uid = null): bool
     {
         $this->logger->debug(
             "Entering isAdmin($uid)", ["app" => $this->appName]

lib/Backend/UserBackend.php

@@ -37,7 +37,7 @@ use OCA\UserSQL\Repository\UserRepository;
 use OCP\EventDispatcher\IEventDispatcher;
 use OCP\IConfig;
 use OCP\IL10N;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 use OCP\Security\Events\ValidatePasswordPolicyEvent;
 use OCP\User\Backend\ABackend;
 use OCP\User\Backend\ICheckPasswordBackend;
@@ -69,7 +69,7 @@ final class UserBackend extends ABackend implements
      */
     private $appName;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -106,7 +106,7 @@ final class UserBackend extends ABackend implements
      *
      * @param string           $AppName         The application name.
      * @param Cache            $cache           The cache instance.
-     * @param ILogger          $logger          The logger instance.
+     * @param LoggerInterface          $logger          The logger instance.
      * @param Properties       $properties      The properties array.
      * @param UserRepository   $userRepository  The user repository.
      * @param IL10N            $localization    The localization service.
@@ -114,7 +114,7 @@ final class UserBackend extends ABackend implements
      * @param IEventDispatcher $eventDispatcher The event dispatcher.
      */
     public function __construct(
-        $AppName, Cache $cache, ILogger $logger, Properties $properties,
+        $AppName, Cache $cache, LoggerInterface $logger, Properties $properties,
         UserRepository $userRepository, IL10N $localization, IConfig $config,
         IEventDispatcher $eventDispatcher
     ) {
@@ -261,9 +261,13 @@ final class UserBackend extends ABackend implements
         if ($user instanceof User) {
             $this->cache->set($cacheKey, $user);
 
+			// avoid recursion as the action may very well call into the UserManager again ...
+			$actions = $this->actions;
+			$this->actions = [];
             foreach ($this->actions as $action) {
                 $action->doAction($user);
             }
+			$this->actions = $actions;
         }
 
         return $user;
@@ -345,9 +349,12 @@ final class UserBackend extends ABackend implements
         }
 
         if ($isCorrect !== true) {
-            $this->logger->info(
+            $this->logger->error(
                 "Invalid password attempt for user: $uid",
-                ["app" => $this->appName]
+                [
+					"app" => $this->appName,
+					'exception' => new \Exception('TRACE PROVIDER'),
+				]
             );
             return false;
         }
@@ -459,6 +466,18 @@ final class UserBackend extends ABackend implements
                 "Returning from cache getUsers($search, $limit, $offset): count("
                 . count($users) . ")", ["app" => $this->appName]
             );
+            // convert to user-model
+            foreach ($users as $index => $cachedUser) {
+              if (!is_array($cachedUser)) {
+                break;
+              }
+              $user = new User();
+              foreach ($cachedUser as $key => $value) {
+                $user->{$key} = $value;
+              }
+              $users[$index] = $user;
+            }
+
             return $users;
         }
 

lib/Cache.php

@@ -5,6 +5,9 @@
  * @copyright 2018 Marcin Łojewski <dev@mlojewski.me>
  * @author    Marcin Łojewski <dev@mlojewski.me>
  *
+ * @copyright 2025 Claus-Justus Heine <himself@claus-justus-heine.de>
+ * @author    Claus-Justus Heine <himself@claus-justus-heine.de>
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
@@ -26,7 +29,7 @@ use OCA\UserSQL\Constant\App;
 use OCA\UserSQL\Constant\Opt;
 use OCP\ICache;
 use OCP\IConfig;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 
 /**
  * Used to store key-value pairs in the cache memory.
@@ -39,16 +42,16 @@ class Cache
     /**
      * @var ICache The cache instance.
      */
-    private $cache;
+    private $cache = null;
 
     /**
      * The default constructor. Initiates the cache memory.
      *
      * @param string  $AppName The application name.
      * @param IConfig $config  The config instance.
-     * @param ILogger $logger  The logger instance.
+     * @param LoggerInterface $logger  The logger instance.
      */
-    public function __construct($AppName, IConfig $config, ILogger $logger)
+    public function __construct($AppName, IConfig $config, LoggerInterface $logger)
     {
         $factory = \OC::$server->getMemCacheFactory();
         $useCache = $config->getAppValue(
@@ -57,15 +60,19 @@ class Cache
 
         if ($useCache === App::FALSE_VALUE) {
             $this->cache = new NullCache();
-        } elseif ($factory->isAvailable()) {
-            $this->cache = $factory->createDistributed();
-            $logger->debug("Distributed cache initiated.", ["app" => $AppName]);
         } else {
-            $logger->warning(
-                "There's no distributed cache available, fallback to null cache.",
+			if ($factory->isAvailable()) {
+				$this->cache = $factory->createDistributed();
+			}
+			if ($this->cache === null || ($this->cache instanceof NullCache)) {
+				$logger->debug(
+					"There's no distributed cache available, fallback to capped in-memory cache.",
 					["app" => $AppName]
 				);
-            $this->cache = new NullCache();
+				$this->cache = $factory->createInMemory(128);
+			} else {
+				$logger->debug("Distributed cache initiated.", ["app" => $AppName]);
+			}
 		}
     }
 

lib/Constant/Query.php

@@ -32,6 +32,7 @@ final class Query
     const COUNT_GROUPS = "count_groups";
     const COUNT_USERS = "count_users";
     const FIND_GROUP = "find_group";
+    const FIND_GROUP_UIDS = "find_group_uids";
     const FIND_GROUP_USERS = "find_group_users";
     const FIND_GROUPS = "find_groups";
     const FIND_USER_BY_UID = "find_user_by_uid";

lib/Controller/SettingsController.php

@@ -37,7 +37,7 @@ use OCA\UserSQL\Platform\PlatformFactory;
 use OCA\UserSQL\Properties;
 use OCP\AppFramework\Controller;
 use OCP\IL10N;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 use OCP\IRequest;
 use ReflectionClass;
 use ReflectionException;
@@ -50,7 +50,7 @@ use ReflectionException;
 class SettingsController extends Controller
 {
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -71,13 +71,13 @@ class SettingsController extends Controller
      *
      * @param string     $appName      The application name.
      * @param IRequest   $request      An instance of the request.
-     * @param ILogger    $logger       The logger instance.
+     * @param LoggerInterface    $logger       The logger instance.
      * @param IL10N      $localization The localization service.
      * @param Properties $properties   The properties array.
      * @param Cache      $cache        The cache instance.
      */
     public function __construct(
-        $appName, IRequest $request, ILogger $logger, IL10N $localization,
+        $appName, IRequest $request, LoggerInterface $logger, IL10N $localization,
         Properties $properties, Cache $cache
     ) {
         parent::__construct($appName, $request);
@@ -92,6 +92,8 @@ class SettingsController extends Controller
      * Verify the database connection parameters.
      *
      * @return array The request status.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function verifyDbConnection()
     {
@@ -189,6 +191,8 @@ class SettingsController extends Controller
      * Save application properties.
      *
      * @return array The request status.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function saveProperties()
     {
@@ -329,6 +333,8 @@ class SettingsController extends Controller
      * Clear the application cache memory.
      *
      * @return array The request status.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function clearCache()
     {
@@ -356,6 +362,8 @@ class SettingsController extends Controller
      * Autocomplete for table select options.
      *
      * @return array The database table list.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function tableAutocomplete()
     {
@@ -376,7 +384,7 @@ class SettingsController extends Controller
 
             return $tables;
         } catch (Exception $e) {
-            $this->logger->logException($e);
+            $this->logger->error('Error during table autocompletion', [ 'exception' => $e ]);
             return [];
         }
     }
@@ -385,6 +393,8 @@ class SettingsController extends Controller
      * Autocomplete for column select options - user table.
      *
      * @return array The database table's column list.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function userTableAutocomplete()
     {
@@ -421,7 +431,7 @@ class SettingsController extends Controller
 
             return $columns;
         } catch (Exception $e) {
-            $this->logger->logException($e);
+            $this->logger->error('Error during column autocompletion', [ 'exception' => $e ]);
             return [];
         }
     }
@@ -430,6 +440,8 @@ class SettingsController extends Controller
      * Autocomplete for column select options - user_group table.
      *
      * @return array The database table's column list.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function userGroupTableAutocomplete()
     {
@@ -451,6 +463,8 @@ class SettingsController extends Controller
      * Autocomplete for column select options - group table.
      *
      * @return array The database table's column list.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function groupTableAutocomplete()
     {
@@ -473,6 +487,8 @@ class SettingsController extends Controller
      *
      * @return array Password algorithm parameters.
      * @throws ReflectionException Whenever Opt class cannot be initiated.
+     *
+     * @AuthorizedAdminSetting(settings=OCA\UserSQL\Settings\Admin)
      */
     public function cryptoParams()
     {

lib/Properties.php

@@ -25,7 +25,7 @@ use OCA\UserSQL\Constant\App;
 use OCA\UserSQL\Constant\DB;
 use OCA\UserSQL\Constant\Opt;
 use OCP\IConfig;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 
 /**
  * Store and retrieve application properties.
@@ -48,7 +48,7 @@ class Properties implements \ArrayAccess
      */
     private $config;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -69,11 +69,11 @@ class Properties implements \ArrayAccess
      *
      * @param string  $AppName The application name.
      * @param IConfig $config  The config instance.
-     * @param ILogger $logger  The logger instance.
+     * @param LoggerInterface $logger  The logger instance.
      * @param Cache   $cache   The cache instance.
      */
     public function __construct(
-        $AppName, IConfig $config, ILogger $logger, Cache $cache
+        $AppName, IConfig $config, LoggerInterface $logger, Cache $cache
     ) {
         $this->appName = $AppName;
         $this->config = $config;
@@ -144,9 +144,7 @@ class Properties implements \ArrayAccess
                     $params, array_values($reflection->getConstants())
                 );
             } catch (\ReflectionException $exception) {
-                $this->logger->logException(
-                    $exception, ["app" => $this->appName]
-                );
+                $this->logger->error('Unable to determine parameter names', [ 'exception'=> $exception ]);
             }
         }
 
@@ -203,7 +201,7 @@ class Properties implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetExists($offset)
+    public function offsetExists(mixed $offset):bool
     {
         return isset($this->data[$offset]);
     }
@@ -211,7 +209,7 @@ class Properties implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetGet($offset)
+    public function offsetGet(mixed $offset):mixed
     {
         if (isset($this->data[$offset])) {
             return $this->data[$offset];
@@ -223,7 +221,7 @@ class Properties implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet(mixed $offset, mixed $value):void
     {
         if ($offset == Opt::SAFE_STORE) {
             $this->safeStore = ($value === App::TRUE_VALUE);
@@ -255,7 +253,7 @@ class Properties implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetUnset($offset)
+    public function offsetUnset(mixed $offset):void
     {
         if ($offset == Opt::SAFE_STORE) {
             $this->safeStore = App::FALSE_VALUE;

lib/Query/DataQuery.php

@@ -28,7 +28,7 @@ use OC\DB\ConnectionFactory;
 use OCA\UserSQL\Constant\DB;
 use OCA\UserSQL\Constant\Query;
 use OCA\UserSQL\Properties;
-use OCP\ILogger;
+use Psr\Log\LoggerInterface;
 
 /**
  * Used to query a database.
@@ -42,7 +42,7 @@ class DataQuery
      */
     private $appName;
     /**
-     * @var ILogger The logger instance.
+     * @var LoggerInterface The logger instance.
      */
     private $logger;
     /**
@@ -62,12 +62,12 @@ class DataQuery
      * The class constructor.
      *
      * @param string        $AppName       The application name.
-     * @param ILogger       $logger        The logger instance.
+     * @param LoggerInterface       $logger        The logger instance.
      * @param Properties    $properties    The properties array.
      * @param QueryProvider $queryProvider The query provider.
      */
     public function __construct(
-        $AppName, ILogger $logger, Properties $properties,
+        $AppName, LoggerInterface $logger, Properties $properties,
         QueryProvider $queryProvider
     ) {
         $this->appName = $AppName;
@@ -109,26 +109,26 @@ class DataQuery
         }
 
         $query = $this->queryProvider[$queryName];
+
+        try {
             $result = $this->connection->prepare($query, $limit, $offset);
+        } catch (DBALException  $exception) {
+            $this->logger->error('Could not prepare the query: ' . $query, [ 'exception' => $exception ]);
+            return false;
+        }
 
         foreach ($params as $param => $value) {
             $result->bindValue(":" . $param, $value);
         }
 
-        $this->logger->debug(
-            "Executing query: " . $query . ", " . implode(",", $params),
-            ["app" => $this->appName]
-        );
+        $this->logger->debug("Executing query: " . $query . ", " . implode(",", $params));
 
         try {
             $result = $result->execute();
             return $result;
 
         } catch (DBALException  $exception) {
-            $this->logger->error(
-                "Could not execute the query: " . $exception->getMessage(),
-                ["app" => $this->appName]
-            );
+            $this->logger->error('Could not execute the query: ' . $query, [ 'exception' => $exception ]);
             return false;
         }
     }
@@ -219,6 +219,27 @@ class DataQuery
         return $result->fetchFirstColumn();
     }
 
+    /**
+     * Fetch values from all columns which the given query returns.
+     *
+     * @param string $queryName The query to execute.
+     * @param array  $params    The query parameters to bind.
+     * @param int    $limit     Results limit. Defaults to -1 (no limit).
+     * @param int    $offset    Results offset. Defaults to 0.
+     *
+     * @return array|bool Queried column or FALSE on failure.
+     */
+    public function queryColumns(
+        $queryName, $params = [], $limit = -1, $offset = 0
+    ) {
+        $result = $this->execQuery($queryName, $params, $limit, $offset);
+        if ($result === false) {
+            return false;
+        }
+
+        return $result->fetchAll();
+    }
+
     /**
      * Fetch entity returned by the given query.
      *

lib/Query/QueryProvider.php

@@ -129,16 +129,21 @@ class QueryProvider implements \ArrayAccess
         $this->queries = [
             Query::BELONGS_TO_ADMIN =>
                 "SELECT COUNT(g.$gGID) > 0 AS admin " .
-                "FROM $group g, $userGroup ug " .
+                "FROM $group g " .
+                "LEFT JOIN $userGroup ug ON ug.$ugGID = g.$gGID " .
+                (empty($uDisabled) ? "" : "LEFT JOIN $user u ON u.$uUID = ug.$ugUID ") .
                 "WHERE ug.$ugGID = g.$gGID " .
                 "AND ug.$ugUID = :$uidParam " .
-                "AND g.$gAdmin",
+                "AND g.$gAdmin" .
+                (empty($uDisabled) ? "" : " AND NOT u.$uDisabled"),
 
             Query::COUNT_GROUPS =>
-                "SELECT COUNT(ug.$ugGID) " .
+                "SELECT COUNT(DISTINCT ug.$ugUID) " .
                 "FROM $userGroup ug " .
+                (empty($uDisabled) ? "" : "LEFT JOIN $user u ON u.$uUID = ug.$ugUID ") .
                 "WHERE ug.$ugGID LIKE :$gidParam " .
-                "AND ug.$ugUID LIKE :$searchParam",
+                "AND ug.$ugUID LIKE :$searchParam" .
+                (empty($uDisabled) ? "" : " AND NOT u.$uDisabled"),
 
             Query::COUNT_USERS =>
                 "SELECT COUNT(u.$uUID) AS count " .
@@ -151,12 +156,23 @@ class QueryProvider implements \ArrayAccess
                 "FROM $group g " .
                 "WHERE g.$gGID = :$gidParam",
 
-            Query::FIND_GROUP_USERS =>
-                "SELECT ug.$ugUID AS uid " .
-                "FROM $userGroup ug " .
+            Query::FIND_GROUP_UIDS =>
+                "SELECT DISTINCT u.$uUID AS uid " .
+                "FROM $user u " .
+                "LEFT JOIN $userGroup ug ON u.$uUID = ug.$ugUID " .
                 "WHERE ug.$ugGID LIKE :$gidParam " .
-                "AND ug.$ugUID LIKE :$searchParam " .
-                "ORDER BY ug.$ugUID",
+                "AND u.$uUID LIKE :$searchParam " .
+                (empty($uDisabled) ? "" : "AND NOT u.$uDisabled ") .
+                "ORDER BY u.$uUID",
+
+            Query::FIND_GROUP_USERS =>
+                "SELECT DISTINCT u.$uUID AS uid, u.$uName AS name " .
+                "FROM $user u " .
+                "LEFT JOIN $userGroup ug ON u.$uUID = ug.$ugUID " .
+                "WHERE ug.$ugGID LIKE :$gidParam " .
+                "AND u.$uUID LIKE :$searchParam " .
+                (empty($uDisabled) ? "" : "AND NOT u.$uDisabled ") .
+                "ORDER BY u.$uUID",
 
             Query::FIND_GROUPS =>
                 "SELECT $groupColumns " .
@@ -197,9 +213,9 @@ class QueryProvider implements \ArrayAccess
 
             Query::FIND_USER_GROUPS =>
                 "SELECT $groupColumns " .
-                "FROM $group g, $userGroup ug " .
-                "WHERE ug.$ugGID = g.$gGID " .
-                "AND ug.$ugUID = :$uidParam " .
+                "FROM $group g " .
+                "LEFT JOIN $userGroup ug ON ug.$ugGID = g.$gGID " .
+                "WHERE ug.$ugUID = :$uidParam " .
                 "ORDER BY g.$gGID",
 
             Query::FIND_USERS =>
@@ -238,7 +254,7 @@ class QueryProvider implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetExists($offset)
+    public function offsetExists(mixed $offset):bool
     {
         return isset($this->queries[$offset]);
     }
@@ -246,7 +262,7 @@ class QueryProvider implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetGet($offset)
+    public function offsetGet(mixed $offset):mixed
     {
         if (isset($this->queries[$offset])) {
             return $this->queries[$offset];
@@ -258,7 +274,7 @@ class QueryProvider implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet(mixed $offset, mixed $value):void
     {
         $this->queries[$offset] = $value;
     }
@@ -266,7 +282,7 @@ class QueryProvider implements \ArrayAccess
     /**
      * @inheritdoc
      */
-    public function offsetUnset($offset)
+    public function offsetUnset(mixed $offset):void
     {
         unset($this->queries[$offset]);
     }

lib/Repository/GroupRepository.php

@@ -92,10 +92,33 @@ class GroupRepository
         $gid, $search = "", $limit = -1, $offset = 0
     ) {
         return $this->dataQuery->queryColumn(
+            Query::FIND_GROUP_UIDS,
+            [Query::GID_PARAM => $gid, Query::SEARCH_PARAM => $search], $limit,
+            $offset
+        );
+    }
+
+    /**
+     * Get a list of all user IDs and their display-name belonging to the group.
+     *
+     * @param string $gid    The group ID.
+     * @param string $search The UID search term. Defaults to "" (empty string).
+     * @param int    $limit  (optional) Results limit.
+     *                       Defaults to -1 (no limit).
+     * @param int    $offset (optional) Results offset. Defaults to 0.
+     *
+     * @return array<string, string> Array of display-names indexed by UIDs belonging to the group
+     *                  or FALSE on failure.
+     */
+    public function findAllUsersBySearchTerm(
+        $gid, $search = "", $limit = -1, $offset = 0
+    ) {
+		$data = $this->dataQuery->queryColumns(
             Query::FIND_GROUP_USERS,
             [Query::GID_PARAM => $gid, Query::SEARCH_PARAM => $search], $limit,
             $offset
         );
+		return array_column($data, QUERY::NAME_PARAM, Query::UID_PARAM);
     }
 
     /**

lib/Settings/Admin.php

@@ -23,14 +23,14 @@ namespace OCA\UserSQL\Settings;
 
 use OCA\UserSQL\Properties;
 use OCP\AppFramework\Http\TemplateResponse;
-use OCP\Settings\ISettings;
+use OCP\Settings\IDelegatedSettings;
 
 /**
  * The administrator's settings page.
  *
  * @author Marcin Łojewski <dev@mlojewski.me>
  */
-class Admin implements ISettings
+class Admin implements IDelegatedSettings
 {
     /**
      * @var string The application name.
@@ -76,4 +76,12 @@ class Admin implements ISettings
     {
         return 25;
     }
+
+    public function getName(): ?string {
+        return null; // Only one setting in this section
+    }
+
+    public function getAuthorizedAppConfig(): array {
+        return []; // Custom controller
+    }
 }