make ILDAPProviderFactory usable when there is no ldap setup

Signed-off-by: Robin Appelman <robin@icewind.nl>

apps/user_ldap/lib/LDAPProviderFactory.php

@@ -41,4 +41,8 @@ public function __construct(IServerContainer $serverContainer) {
 	public function getLDAPProvider(): ILDAPProvider {
 		return $this->serverContainer->get(LDAPProvider::class);
 	}
+
+	public function isAvailable(): bool {
+		return true;
+	}
 }

lib/private/LDAP/NullLDAPProviderFactory.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Robin Appelman <robin@icewind.nl>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\LDAP;
+
+
+use OCP\IServerContainer;
+use OCP\LDAP\ILDAPProviderFactory;
+
+class NullLDAPProviderFactory implements ILDAPProviderFactory {
+	public function __construct(IServerContainer $serverContainer) {
+	}
+
+	public function getLDAPProvider() {
+		throw new \Exception("No LDAP provider is available");
+	}
+
+	public function isAvailable(): bool {
+		return false;
+	}
+}

lib/private/Server.php

@@ -103,6 +103,7 @@
 use OC\IntegrityCheck\Helpers\AppLocator;
 use OC\IntegrityCheck\Helpers\EnvironmentHelper;
 use OC\IntegrityCheck\Helpers\FileAccessHelper;
+use OC\LDAP\NullLDAPProviderFactory;
 use OC\Lock\DBLockingProvider;
 use OC\Lock\MemcacheLockingProvider;
 use OC\Lock\NoopLockingProvider;
@@ -203,6 +204,8 @@
 use OCP\IUserManager;
 use OCP\IUserSession;
 use OCP\L10N\IFactory;
+use OCP\LDAP\ILDAPProvider;
+use OCP\LDAP\ILDAPProviderFactory;
 use OCP\Lock\ILockingProvider;
 use OCP\Log\ILogFactory;
 use OCP\Mail\IMailer;
@@ -996,14 +999,20 @@ public function __construct($webRoot, \OC\Config $config) {
 		/** @deprecated 19.0.0 */
 		$this->registerDeprecatedAlias('Mailer', IMailer::class);
 
-		$this->registerService('LDAPProvider', function (ContainerInterface $c) {
+		/** @deprecated 21.0.0 */
+		$this->registerDeprecatedAlias('LDAPProvider', ILDAPProvider::class);
+
+		$this->registerService(ILDAPProviderFactory::class, function (ContainerInterface $c) {
 			$config = $c->get(\OCP\IConfig::class);
 			$factoryClass = $config->getSystemValue('ldapProviderFactory', null);
 			if (is_null($factoryClass)) {
-				throw new \Exception('ldapProviderFactory not set');
+				return new NullLDAPProviderFactory($this);
 			}
 			/** @var \OCP\LDAP\ILDAPProviderFactory $factory */
-			$factory = new $factoryClass($this);
+			return new $factoryClass($this);
+		});
+		$this->registerService(ILDAPProvider::class, function (ContainerInterface $c) {
+			$factory = $c->get(ILDAPProviderFactory::class);
 			return $factory->getLDAPProvider();
 		});
 		$this->registerService(ILockingProvider::class, function (ContainerInterface $c) {

lib/public/LDAP/ILDAPProviderFactory.php

@@ -44,12 +44,19 @@ interface ILDAPProviderFactory {
 	 * @since 11.0.0
 	 */
 	public function __construct(IServerContainer $serverContainer);
-	
+
 	/**
 	 * creates and returns an instance of the ILDAPProvider
 	 *
 	 * @return ILDAPProvider
 	 * @since 11.0.0
 	 */
 	public function getLDAPProvider();
+
+	/**
+	 * Check if an ldap provider is available
+	 *
+	 * @return bool
+	 */
+	public function isAvailable(): bool;
 }