Add event dispatcher to OCP

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

8 files changed, 325 insertions, 23 deletions

diff --git a/lib/private/DB/Migrator.php b/lib/private/DB/Migrator.php
index 603f9259d6e..a853ab1ea1b 100644
--- a/lib/private/DB/Migrator.php
+++ b/lib/private/DB/Migrator.php
@@ -39,7 +39,7 @@ use Doctrine\DBAL\Types\StringType;
 use Doctrine\DBAL\Types\Type;
 use OCP\IConfig;
 use OCP\Security\ISecureRandom;
-use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\GenericEvent;
 
 class Migrator {
@@ -53,7 +53,7 @@ class Migrator {
 	/** @var IConfig */
 	protected $config;
 
-	/** @var EventDispatcher  */
+	/** @var EventDispatcherInterface  */
 	private $dispatcher;
 
 	/** @var bool */
@@ -63,12 +63,12 @@ class Migrator {
 	 * @param \Doctrine\DBAL\Connection|Connection $connection
 	 * @param ISecureRandom $random
 	 * @param IConfig $config
-	 * @param EventDispatcher $dispatcher
+	 * @param EventDispatcherInterface $dispatcher
 	 */
 	public function __construct(\Doctrine\DBAL\Connection $connection,
 								ISecureRandom $random,
 								IConfig $config,
-								EventDispatcher $dispatcher = null) {
+								EventDispatcherInterface $dispatcher = null) {
 		$this->connection = $connection;
 		$this->random = $random;
 		$this->config = $config;
diff --git a/lib/private/EventDispatcher/EventDispatcher.php b/lib/private/EventDispatcher/EventDispatcher.php
new file mode 100644
index 00000000000..8db2f3101be
--- /dev/null
+++ b/lib/private/EventDispatcher/EventDispatcher.php
@@ -0,0 +1,85 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2019 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2019 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @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\EventDispatcher;
+
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\IContainer;
+use OCP\ILogger;
+use OCP\IServerContainer;
+use Symfony\Component\EventDispatcher\EventDispatcher as SymfonyDispatcher;
+
+class EventDispatcher implements IEventDispatcher {
+
+	/** @var SymfonyDispatcher */
+	private $dispatcher;
+
+	/** @var IContainer */
+	private $container;
+
+	/** @var ILogger */
+	private $logger;
+
+	public function __construct(SymfonyDispatcher $dispatcher,
+								IServerContainer $container,
+								ILogger $logger) {
+		$this->dispatcher = $dispatcher;
+		$this->container = $container;
+		$this->logger = $logger;
+	}
+
+	public function addListener(string $eventName,
+								callable $listener,
+								int $priority = 0): void {
+		$this->dispatcher->addListener($eventName, $listener, $priority);
+	}
+
+	public function addServiceListener(string $eventName,
+									   string $className,
+									   int $priority = 0): void {
+		$listener = new ServiceEventListener(
+			$this->container,
+			$className,
+			$this->logger
+		);
+
+		$this->addListener($eventName, $listener, $priority);
+	}
+
+	public function dispatch(string $eventName,
+							 Event $event): void {
+
+		$this->dispatcher->dispatch($eventName, $event);
+	}
+
+	/**
+	 * @return SymfonyDispatcher
+	 */
+	public function getSymfonyDispatcher(): SymfonyDispatcher {
+		return $this->dispatcher;
+	}
+
+}
diff --git a/lib/private/EventDispatcher/ServiceEventListener.php b/lib/private/EventDispatcher/ServiceEventListener.php
new file mode 100644
index 00000000000..f5b6cd9b79d
--- /dev/null
+++ b/lib/private/EventDispatcher/ServiceEventListener.php
@@ -0,0 +1,78 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2019 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2019 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @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\EventDispatcher;
+
+use OCP\AppFramework\QueryException;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventListener;
+use OCP\IContainer;
+use OCP\ILogger;
+
+/**
+ * Lazy service event listener
+ *
+ * Makes it possible to lazy-route a dispatched event to a service instance
+ * created by the service container
+ */
+final class ServiceEventListener {
+
+	/** @var IContainer */
+	private $container;
+
+	/** @var string */
+	private $class;
+
+	/** @var ILogger */
+	private $logger;
+
+	/** @var null|IEventListener */
+	private $service;
+
+	public function __construct(IContainer $container,
+								string $class,
+								ILogger $logger) {
+		$this->container = $container;
+		$this->class = $class;
+		$this->logger = $logger;
+	}
+
+	public function __invoke(Event $event) {
+		if ($this->service === null) {
+			try {
+				$this->service = $this->container->query($this->class);
+			} catch (QueryException $e) {
+				$this->logger->logException($e, [
+					'level' => ILogger::ERROR,
+					'message' => "Could not load event listener service " . $this->class,
+				]);
+				return;
+			}
+		}
+
+		$this->service->handle($event);
+	}
+
+}
diff --git a/lib/private/EventDispatcher/SymfonyAdapter.php b/lib/private/EventDispatcher/SymfonyAdapter.php
new file mode 100644
index 00000000000..f2f2fbf59fd
--- /dev/null
+++ b/lib/private/EventDispatcher/SymfonyAdapter.php
@@ -0,0 +1,140 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2019 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2019 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @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\EventDispatcher;
+
+use function is_callable;
+use OCP\EventDispatcher\Event;
+use Symfony\Component\EventDispatcher\Event as SymfonyEvent;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+class SymfonyAdapter implements EventDispatcherInterface {
+
+	/** @var EventDispatcher */
+	private $eventDispatcher;
+
+	public function __construct(EventDispatcher $eventDispatcher) {
+		$this->eventDispatcher = $eventDispatcher;
+	}
+
+	/**
+	 * Dispatches an event to all registered listeners.
+	 *
+	 * @param string $eventName The name of the event to dispatch. The name of
+	 *                              the event is the name of the method that is
+	 *                              invoked on listeners.
+	 * @param SymfonyEvent|null $event The event to pass to the event handlers/listeners
+	 *                              If not supplied, an empty Event instance is created
+	 *
+	 * @return SymfonyEvent
+	 */
+	public function dispatch($eventName, SymfonyEvent $event = null) {
+		if ($event instanceof Event) {
+			$this->eventDispatcher->dispatch($eventName, $event);
+		} else {
+			// Legacy event
+			$this->eventDispatcher->getSymfonyDispatcher()->dispatch($eventName, $event);
+		}
+	}
+
+	/**
+	 * Adds an event listener that listens on the specified events.
+	 *
+	 * @param string $eventName The event to listen on
+	 * @param callable $listener The listener
+	 * @param int $priority The higher this value, the earlier an event
+	 *                            listener will be triggered in the chain (defaults to 0)
+	 */
+	public function addListener($eventName, $listener, $priority = 0) {
+		if (is_callable($listener)) {
+			$this->eventDispatcher->addListener($eventName, $listener, $priority);
+		} else {
+			// Legacy listener
+			$this->eventDispatcher->getSymfonyDispatcher()->addListener($eventName, $listener, $priority);
+		}
+	}
+
+	/**
+	 * Adds an event subscriber.
+	 *
+	 * The subscriber is asked for all the events it is
+	 * interested in and added as a listener for these events.
+	 */
+	public function addSubscriber(EventSubscriberInterface $subscriber) {
+		$this->eventDispatcher->getSymfonyDispatcher()->addSubscriber($subscriber);
+	}
+
+	/**
+	 * Removes an event listener from the specified events.
+	 *
+	 * @param string $eventName The event to remove a listener from
+	 * @param callable $listener The listener to remove
+	 */
+	public function removeListener($eventName, $listener) {
+		$this->eventDispatcher->getSymfonyDispatcher()->removeListener($eventName, $listener);
+	}
+
+	public function removeSubscriber(EventSubscriberInterface $subscriber) {
+		$this->eventDispatcher->getSymfonyDispatcher()->removeSubscriber($subscriber);
+	}
+
+	/**
+	 * Gets the listeners of a specific event or all listeners sorted by descending priority.
+	 *
+	 * @param string|null $eventName The name of the event
+	 *
+	 * @return array The event listeners for the specified event, or all event listeners by event name
+	 */
+	public function getListeners($eventName = null) {
+		return $this->eventDispatcher->getSymfonyDispatcher()->getListeners($eventName);
+	}
+
+	/**
+	 * Gets the listener priority for a specific event.
+	 *
+	 * Returns null if the event or the listener does not exist.
+	 *
+	 * @param string $eventName The name of the event
+	 * @param callable $listener The listener
+	 *
+	 * @return int|null The event listener priority
+	 */
+	public function getListenerPriority($eventName, $listener) {
+		return $this->eventDispatcher->getSymfonyDispatcher()->getListenerPriority($eventName, $listener);
+	}
+
+	/**
+	 * Checks whether an event has any registered listeners.
+	 *
+	 * @param string|null $eventName The name of the event
+	 *
+	 * @return bool true if the specified event has any listeners, false otherwise
+	 */
+	public function hasListeners($eventName = null) {
+		return $this->eventDispatcher->getSymfonyDispatcher()->hasListeners($eventName);
+	}
+
+}
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 408b457ec39..2b08b0bab15 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -128,7 +128,6 @@ use OCA\Theming\ThemingDefaults;
 
 use OCP\Accounts\IAccountManager;
 use OCP\App\IAppManager;
-use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\Collaboration\AutoComplete\IManager;
 use OCP\Contacts\ContactsMenu\IContactsStore;
 use OCP\Dashboard\IDashboardManager;
@@ -158,7 +157,6 @@ use OCP\Remote\IInstanceFactory;
 use OCP\RichObjectStrings\IValidator;
 use OCP\Security\IContentSecurityPolicyManager;
 use OCP\Share\IShareHelper;
-use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\GenericEvent;
 
@@ -989,11 +987,9 @@ class Server extends ServerContainer implements IServerContainer {
 				$c->getLogger()
 			);
 		});
-		$this->registerService(EventDispatcher::class, function () {
-			return new EventDispatcher();
-		});
-		$this->registerAlias('EventDispatcher', EventDispatcher::class);
-		$this->registerAlias(EventDispatcherInterface::class, EventDispatcher::class);
+		$this->registerAlias(\OCP\EventDispatcher\IEventDispatcher::class, \OC\EventDispatcher\EventDispatcher::class);
+		$this->registerAlias('EventDispatcher', \OC\EventDispatcher\SymfonyAdapter::class);
+		$this->registerAlias(EventDispatcherInterface::class, \OC\EventDispatcher\SymfonyAdapter::class);
 
 		$this->registerService('CryptoWrapper', function (Server $c) {
 			// FIXME: Instantiiated here due to cyclic dependency
@@ -1858,7 +1854,7 @@ class Server extends ServerContainer implements IServerContainer {
 	 * @since 8.2.0
 	 */
 	public function getEventDispatcher() {
-		return $this->query('EventDispatcher');
+		return $this->query(\OC\EventDispatcher\SymfonyAdapter::class);
 	}
 
 	/**
diff --git a/lib/private/Share20/LegacyHooks.php b/lib/private/Share20/LegacyHooks.php
index c3a4e9d999d..4cc748aa418 100644
--- a/lib/private/Share20/LegacyHooks.php
+++ b/lib/private/Share20/LegacyHooks.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * @copyright 2017, Roeland Jago Douma <roeland@famdouma.nl>
  *
@@ -21,24 +22,26 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
+
 namespace OC\Share20;
 
 use OCP\Files\File;
 use OCP\Share\IShare;
-use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\GenericEvent;
 use OCP\Share;
 
 class LegacyHooks {
-	/** @var EventDispatcher */
+
+	/** @var EventDispatcherInterface */
 	private $eventDispatcher;
 
 	/**
 	 * LegacyHooks constructor.
 	 *
-	 * @param EventDispatcher $eventDispatcher
+	 * @param EventDispatcherInterface $eventDispatcher
 	 */
-	public function __construct(EventDispatcher $eventDispatcher) {
+	public function __construct(EventDispatcherInterface $eventDispatcher) {
 		$this->eventDispatcher = $eventDispatcher;
 
 		$this->eventDispatcher->addListener('OCP\Share::preUnshare', [$this, 'preUnshare']);
diff --git a/lib/private/Share20/Manager.php b/lib/private/Share20/Manager.php
index c2ea165955f..e71b6f98321 100644
--- a/lib/private/Share20/Manager.php
+++ b/lib/private/Share20/Manager.php
@@ -62,7 +62,7 @@ use OCP\Share\Exceptions\ShareNotFound;
 use OCP\Share\IManager;
 use OCP\Share\IProviderFactory;
 use OCP\Share\IShare;
-use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\GenericEvent;
 use OCP\Share\IShareProvider;
 use OCP\Share;
@@ -96,7 +96,7 @@ class Manager implements IManager {
 	private $rootFolder;
 	/** @var CappedMemoryCache */
 	private $sharingDisabledForUsersCache;
-	/** @var EventDispatcher */
+	/** @var EventDispatcherInterface */
 	private $eventDispatcher;
 	/** @var LegacyHooks */
 	private $legacyHooks;
@@ -122,7 +122,7 @@ class Manager implements IManager {
 	 * @param IProviderFactory $factory
 	 * @param IUserManager $userManager
 	 * @param IRootFolder $rootFolder
-	 * @param EventDispatcher $eventDispatcher
+	 * @param EventDispatcherInterface $eventDispatcher
 	 * @param IMailer $mailer
 	 * @param IURLGenerator $urlGenerator
 	 * @param \OC_Defaults $defaults
@@ -139,7 +139,7 @@ class Manager implements IManager {
 			IProviderFactory $factory,
 			IUserManager $userManager,
 			IRootFolder $rootFolder,
-			EventDispatcher $eventDispatcher,
+			EventDispatcherInterface $eventDispatcher,
 			IMailer $mailer,
 			IURLGenerator $urlGenerator,
 			\OC_Defaults $defaults
diff --git a/lib/private/User/Database.php b/lib/private/User/Database.php
index 27dcb2fc331..8c00060e196 100644
--- a/lib/private/User/Database.php
+++ b/lib/private/User/Database.php
@@ -67,7 +67,7 @@ use OCP\User\Backend\IGetDisplayNameBackend;
 use OCP\User\Backend\IGetHomeBackend;
 use OCP\User\Backend\ISetDisplayNameBackend;
 use OCP\User\Backend\ISetPasswordBackend;
-use Symfony\Component\EventDispatcher\EventDispatcher;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\GenericEvent;
 
 /**
@@ -84,7 +84,7 @@ class Database extends ABackend
 	/** @var CappedMemoryCache */
 	private $cache;
 
-	/** @var EventDispatcher */
+	/** @var EventDispatcherInterface */
 	private $eventDispatcher;
 
 	/** @var IDBConnection */
@@ -96,7 +96,7 @@ class Database extends ABackend
 	/**
 	 * \OC\User\Database constructor.
 	 *
-	 * @param EventDispatcher $eventDispatcher
+	 * @param EventDispatcherInterface $eventDispatcher
 	 * @param string $table
 	 */
 	public function __construct($eventDispatcher = null, $table = 'users') {