Make the root collection neutral so it does not only work for files

apps/comments/appinfo/app.php

@@ -51,3 +51,10 @@ $managerListener = function(\OCP\Comments\CommentsEvent $event) use ($activityMa
 };
 
 $eventDispatcher->addListener(\OCP\Comments\CommentsEvent::EVENT_ADD, $managerListener);
+
+$eventDispatcher->addListener(\OCP\Comments\CommentsEntityEvent::EVENT_ENTITY, function(\OCP\Comments\CommentsEntityEvent $event) {
+	$event->addEntityCollection('files', function($name) {
+		$nodes = \OC::$server->getUserFolder()->getById(intval($name));
+		return !empty($nodes);
+	});
+});

apps/dav/lib/Comments/EntityTypeCollection.php

@@ -44,21 +44,27 @@ class EntityTypeCollection extends RootCollection {
 	/** @var ILogger */
 	protected $logger;
 
+	/** @var IUserManager */
+	protected $userManager;
+
+	/** @var \Closure */
+	protected $childExistsFunction;
+
 	/**
 	 * @param string $name
 	 * @param ICommentsManager $commentsManager
-	 * @param Folder $fileRoot
 	 * @param IUserManager $userManager
 	 * @param IUserSession $userSession
 	 * @param ILogger $logger
+	 * @param \Closure $childExistsFunction
 	 */
 	public function __construct(
 		$name,
 		ICommentsManager $commentsManager,
-		Folder $fileRoot,
 		IUserManager $userManager,
 		IUserSession $userSession,
-		ILogger $logger
+		ILogger $logger,
+		\Closure $childExistsFunction
 	) {
 		$name = trim($name);
 		if(empty($name) || !is_string($name)) {
@@ -66,10 +72,10 @@ class EntityTypeCollection extends RootCollection {
 		}
 		$this->name = $name;
 		$this->commentsManager = $commentsManager;
-		$this->fileRoot = $fileRoot;
 		$this->logger = $logger;
 		$this->userManager = $userManager;
 		$this->userSession = $userSession;
+		$this->childExistsFunction = $childExistsFunction;
 	}
 
 	/**
@@ -113,8 +119,7 @@ class EntityTypeCollection extends RootCollection {
 	 * @return bool
 	 */
 	function childExists($name) {
-		$nodes = $this->fileRoot->getById(intval($name));
-		return !empty($nodes);
+		return call_user_func($this->childExistsFunction, $name);
 	}
 
 }

apps/dav/lib/Comments/RootCollection.php

@@ -21,8 +21,8 @@
 
 namespace OCA\DAV\Comments;
 
+use OCP\Comments\CommentsEntityEvent;
 use OCP\Comments\ICommentsManager;
-use OCP\Files\IRootFolder;
 use OCP\ILogger;
 use OCP\IUserManager;
 use OCP\IUserSession;
@@ -30,11 +30,12 @@ use Sabre\DAV\Exception\NotAuthenticated;
 use Sabre\DAV\Exception\Forbidden;
 use Sabre\DAV\Exception\NotFound;
 use Sabre\DAV\ICollection;
+use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 
 class RootCollection implements ICollection {
 
-	/** @var EntityTypeCollection[] */
-	private $entityTypeCollections = [];
+	/** @var EntityTypeCollection[]|null */
+	private $entityTypeCollections;
 
 	/** @var ICommentsManager */
 	protected $commentsManager;
@@ -47,34 +48,32 @@ class RootCollection implements ICollection {
 
 	/** @var IUserManager */
 	protected $userManager;
-	/**
-	 * @var IUserSession
-	 */
+
+	/** @var IUserSession */
 	protected $userSession;
-	/**
-	 * @var IRootFolder
-	 */
-	protected $rootFolder;
+
+	/** @var EventDispatcherInterface */
+	protected $dispatcher;
 
 	/**
 	 * @param ICommentsManager $commentsManager
 	 * @param IUserManager $userManager
 	 * @param IUserSession $userSession
-	 * @param IRootFolder $rootFolder
+	 * @param EventDispatcherInterface $dispatcher
 	 * @param ILogger $logger
 	 */
 	public function __construct(
 		ICommentsManager $commentsManager,
 		IUserManager $userManager,
 		IUserSession $userSession,
-		IRootFolder $rootFolder,
+		EventDispatcherInterface $dispatcher,
 		ILogger $logger)
 	{
 		$this->commentsManager = $commentsManager;
 		$this->logger = $logger;
 		$this->userManager = $userManager;
 		$this->userSession = $userSession;
-		$this->rootFolder = $rootFolder;
+		$this->dispatcher = $dispatcher;
 	}
 
 	/**
@@ -85,22 +84,28 @@ class RootCollection implements ICollection {
 	 * @throws NotAuthenticated
 	 */
 	protected function initCollections() {
-		if(!empty($this->entityTypeCollections)) {
+		if($this->entityTypeCollections !== null) {
 			return;
 		}
 		$user = $this->userSession->getUser();
 		if(is_null($user)) {
 			throw new NotAuthenticated();
 		}
-		$userFolder = $this->rootFolder->getUserFolder($user->getUID());
-		$this->entityTypeCollections['files'] = new EntityTypeCollection(
-			'files',
-			$this->commentsManager,
-			$userFolder,
-			$this->userManager,
-			$this->userSession,
-			$this->logger
-		);
+
+		$event = new CommentsEntityEvent(CommentsEntityEvent::EVENT_ENTITY);
+		$this->dispatcher->dispatch(CommentsEntityEvent::EVENT_ENTITY, $event);
+
+		$this->entityTypeCollections = [];
+		foreach ($event->getEntityCollections() as $entity => $entityExistsFunction) {
+			$this->entityTypeCollections[$entity] = new EntityTypeCollection(
+				$entity,
+				$this->commentsManager,
+				$this->userManager,
+				$this->userSession,
+				$this->logger,
+				$entityExistsFunction
+			);
+		}
 	}
 
 	/**

apps/dav/lib/RootCollection.php

@@ -77,7 +77,7 @@ class RootCollection extends SimpleCollection {
 			\OC::$server->getCommentsManager(),
 			\OC::$server->getUserManager(),
 			\OC::$server->getUserSession(),
-			\OC::$server->getRootFolder(),
+			\OC::$server->getEventDispatcher(),
 			\OC::$server->getLogger()
 		);
 

lib/public/comments/commentsentityevent.php

@@ -0,0 +1,76 @@
+<?php
+/**
+ * @author Joas Schilling <nickvergessen@owncloud.com>
+ *
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OCP\Comments;
+
+use Symfony\Component\EventDispatcher\Event;
+
+/**
+ * Class CommentsEntityEvent
+ *
+ * @package OCP\Comments
+ * @since 9.1.0
+ */
+class CommentsEntityEvent extends Event {
+
+	const EVENT_ENTITY = 'OCP\Comments\ICommentsManager::registerEntity';
+
+	/** @var string */
+	protected $event;
+	/** @var \Closure[] */
+	protected $collections;
+
+	/**
+	 * DispatcherEvent constructor.
+	 *
+	 * @param string $event
+	 * @since 9.1.0
+	 */
+	public function __construct($event) {
+		$this->event = $event;
+		$this->collections = [];
+	}
+
+	/**
+	 * @param string $name
+	 * @param \Closure $entityExistsFunction The closure should take one
+	 *                 argument, which is the id of the entity, that comments
+	 *                 should be handled for. The return should then be bool,
+	 *                 depending on whether comments are allowed (true) or not.
+	 * @throws \OutOfBoundsException when the entity name is already taken
+	 * @since 9.1.0
+	 */
+	public function addEntityCollection($name, \Closure $entityExistsFunction) {
+		if (isset($this->collections[$name])) {
+			throw new \OutOfBoundsException('Duplicate entity name "' . $name . '"');
+		}
+
+		$this->collections[$name] = $entityExistsFunction;
+	}
+
+	/**
+	 * @return \Closure[]
+	 * @since 9.1.0
+	 */
+	public function getEntityCollections() {
+		return $this->collections;
+	}
+}