Tries middleware to return json.

lib/AppInfo/Application.php

+<?php
+/**
+ * @copyright Copyright (c) 2016 Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Daniel Kesselberg <mail@danielkesselberg.de>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Lukas Reschke <lukas@statuscode.ch>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Vincent Petry <vincent@nextcloud.com>
+ *
+ * @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 OCA\SCIMServiceProvider\AppInfo;
+
+use OC\Group\Manager as GroupManager;
+use OCA\Provisioning_API\Capabilities;
+use OCA\Provisioning_API\Listener\UserDeletedListener;
+use OCA\SCIMServiceProvider\Middleware\SCIMApiMiddleware;
+use OCA\Settings\Mailer\NewUserMailHelper;
+use OCP\AppFramework\App;
+use OCP\AppFramework\Bootstrap\IBootContext;
+use OCP\AppFramework\Bootstrap\IBootstrap;
+use OCP\AppFramework\Bootstrap\IRegistrationContext;
+use OCP\AppFramework\Utility\IControllerMethodReflector;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Defaults;
+use OCP\IConfig;
+use OCP\IGroupManager;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\IUserManager;
+use OCP\L10N\IFactory;
+use OCP\Mail\IMailer;
+use OCP\Security\ICrypto;
+use OCP\Security\ISecureRandom;
+use OCP\User\Events\UserDeletedEvent;
+use OCP\Util;
+use Psr\Container\ContainerInterface;
+
+class Application extends App implements IBootstrap {
+	public function __construct(array $urlParams = []) {
+		parent::__construct('scimserviceprovider', $urlParams);
+	}
+
+	public function register(IRegistrationContext $context): void {
+		$context->registerMiddleware(SCIMApiMiddleware::class);
+	}
+
+	public function boot(IBootContext $context): void {
+	}
+}

lib/Middleware/SCIMApiMiddleware.php

+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2016 Roeland Jago Douma <roeland@famdouma.nl>
+ *
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Lukas Reschke <lukas@statuscode.ch>
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Roeland Jago Douma <roeland@famdouma.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 OCA\SCIMServiceProvider\Middleware;
+
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\JSONResponse;
+use OCP\AppFramework\Middleware;
+use OCP\AppFramework\Utility\IControllerMethodReflector;
+use OCA\SCIMServiceProvider\Responses\SCIMResourceResponse;
+
+class SCIMApiMiddleware extends Middleware {
+
+	/** @var IControllerMethodReflector */
+	private $reflector;
+
+	/** @var bool */
+	private $isAdmin;
+
+	/** @var bool */
+	private $isSubAdmin;
+
+	/**
+	 * ProvisioningApiMiddleware constructor.
+	 *
+	 * @param IControllerMethodReflector $reflector
+	 * @param bool $isAdmin
+	 * @param bool $isSubAdmin
+	 */
+	public function __construct(
+		IControllerMethodReflector $reflector,
+		bool $isAdmin,
+		bool $isSubAdmin) {
+		$this->reflector = $reflector;
+		$this->isAdmin = $isAdmin;
+		$this->isSubAdmin = $isSubAdmin;
+	}
+
+	/**
+	 * @param Controller $controller
+	 * @param string $methodName
+	 * @param \Exception $exception
+	 * @throws \Exception
+	 * @return SCIMResourceResponse
+	 */
+	public function afterException($controller, $methodName, \Exception $exception) {
+		if ($exception instanceof SCIMException) {
+			return SCIMResourceResponse($exception->getMessage(), 500);
+		}
+		return SCIMResourceResponse([
+			"schema" => "error"
+		],500);
+	}
+}