Implement systemtags through webdav

apps/dav/composer/composer/autoload_classmap.php

@@ -304,6 +304,7 @@
     'OCA\\DAV\\Settings\\AvailabilitySettings' => $baseDir . '/../lib/Settings/AvailabilitySettings.php',
     'OCA\\DAV\\Settings\\CalDAVSettings' => $baseDir . '/../lib/Settings/CalDAVSettings.php',
     'OCA\\DAV\\Storage\\PublicOwnerWrapper' => $baseDir . '/../lib/Storage/PublicOwnerWrapper.php',
+    'OCA\\DAV\\SystemTag\\SystemTagList' => $baseDir . '/../lib/SystemTag/SystemTagList.php',
     'OCA\\DAV\\SystemTag\\SystemTagMappingNode' => $baseDir . '/../lib/SystemTag/SystemTagMappingNode.php',
     'OCA\\DAV\\SystemTag\\SystemTagNode' => $baseDir . '/../lib/SystemTag/SystemTagNode.php',
     'OCA\\DAV\\SystemTag\\SystemTagPlugin' => $baseDir . '/../lib/SystemTag/SystemTagPlugin.php',

apps/dav/composer/composer/autoload_static.php

@@ -319,6 +319,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Settings\\AvailabilitySettings' => __DIR__ . '/..' . '/../lib/Settings/AvailabilitySettings.php',
         'OCA\\DAV\\Settings\\CalDAVSettings' => __DIR__ . '/..' . '/../lib/Settings/CalDAVSettings.php',
         'OCA\\DAV\\Storage\\PublicOwnerWrapper' => __DIR__ . '/..' . '/../lib/Storage/PublicOwnerWrapper.php',
+        'OCA\\DAV\\SystemTag\\SystemTagList' => __DIR__ . '/..' . '/../lib/SystemTag/SystemTagList.php',
         'OCA\\DAV\\SystemTag\\SystemTagMappingNode' => __DIR__ . '/..' . '/../lib/SystemTag/SystemTagMappingNode.php',
         'OCA\\DAV\\SystemTag\\SystemTagNode' => __DIR__ . '/..' . '/../lib/SystemTag/SystemTagNode.php',
         'OCA\\DAV\\SystemTag\\SystemTagPlugin' => __DIR__ . '/..' . '/../lib/SystemTag/SystemTagPlugin.php',

apps/dav/lib/Server.php

@@ -208,11 +208,7 @@ public function __construct(IRequest $request, string $baseUri) {
 		}
 
 		// system tags plugins
-		$this->server->addPlugin(new SystemTagPlugin(
-			\OC::$server->getSystemTagManager(),
-			\OC::$server->getGroupManager(),
-			\OC::$server->getUserSession()
-		));
+		$this->server->addPlugin(\OC::$server->get(SystemTagPlugin::class));
 
 		// comments plugin
 		$this->server->addPlugin(new CommentsPlugin(

apps/dav/lib/SystemTag/SystemTagList.php

@@ -0,0 +1,73 @@
+<?php
+/**
+ * @copyright Copyright (c) 2023 Robin Appelman <robin@icewind.nl>
+ *
+ * @author Robin Appelman <robin@icewind.nl>
+ *
+ * @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 OCA\DAV\SystemTag;
+
+use OCP\IUser;
+use OCP\SystemTag\ISystemTag;
+use OCP\SystemTag\ISystemTagManager;
+use Sabre\Xml\Element;
+use Sabre\Xml\Reader;
+use Sabre\Xml\Writer;
+
+/**
+ * TagList property
+ *
+ * This property contains multiple "tag" elements, each containing a tag name.
+ */
+class SystemTagList implements Element {
+	public const NS_NEXTCLOUD = 'http://nextcloud.org/ns';
+
+	/** @var ISystemTag[] */
+	private array $tags;
+	private ISystemTagManager $tagManager;
+	private IUser $user;
+
+	public function __construct(array $tags, ISystemTagManager $tagManager, IUser $user) {
+		$this->tags = $tags;
+		$this->tagManager = $tagManager;
+		$this->user = $user;
+	}
+
+	/**
+	 * @return ISystemTag[]
+	 */
+	public function getTags(): array {
+		return $this->tags;
+	}
+
+	public static function xmlDeserialize(Reader $reader): void {
+		// unsupported/unused
+	}
+
+	public function xmlSerialize(Writer $writer): void {
+		foreach ($this->tags as $tag) {
+			$writer->startElement('{' . self::NS_NEXTCLOUD . '}system-tag');
+			$writer->writeAttributes([
+				SystemTagPlugin::CANASSIGN_PROPERTYNAME => $this->tagManager->canUserAssignTag($tag, $this->user) ? 'true' : 'false',
+				SystemTagPlugin::ID_PROPERTYNAME => $tag->getId(),
+				SystemTagPlugin::USERASSIGNABLE_PROPERTYNAME => $tag->isUserAssignable() ? 'true' : 'false',
+				SystemTagPlugin::USERVISIBLE_PROPERTYNAME => $tag->isUserVisible() ? 'true' : 'false',
+			]);
+			$writer->write($tag->getName());
+			$writer->endElement();
+		}
+	}
+}

apps/dav/lib/SystemTag/SystemTagMappingNode.php

@@ -137,6 +137,8 @@ public function getName() {
 	 * @param string $name The new name
 	 *
 	 * @throws MethodNotAllowed not allowed to rename node
+	 *
+	 * @return never
 	 */
 	public function setName($name) {
 		throw new MethodNotAllowed();
@@ -145,13 +147,16 @@ public function setName($name) {
 	/**
 	 * Returns null, not supported
 	 *
+	 * @return null
 	 */
 	public function getLastModified() {
 		return null;
 	}
 
 	/**
 	 * Delete tag to object association
+	 *
+	 * @return void
 	 */
 	public function delete() {
 		try {

apps/dav/lib/SystemTag/SystemTagNode.php

@@ -103,6 +103,8 @@ public function getSystemTag() {
 	 * @param string $name The new name
 	 *
 	 * @throws MethodNotAllowed not allowed to rename node
+	 *
+	 * @return never
 	 */
 	public function setName($name) {
 		throw new MethodNotAllowed();
@@ -114,11 +116,12 @@ public function setName($name) {
 	 * @param string $name new tag name
 	 * @param bool $userVisible user visible
 	 * @param bool $userAssignable user assignable
+	 *
 	 * @throws NotFound whenever the given tag id does not exist
 	 * @throws Forbidden whenever there is no permission to update said tag
 	 * @throws Conflict whenever a tag already exists with the given attributes
 	 */
-	public function update($name, $userVisible, $userAssignable) {
+	public function update($name, $userVisible, $userAssignable): void {
 		try {
 			if (!$this->tagManager->canUserSeeTag($this->tag, $this->user)) {
 				throw new NotFound('Tag with id ' . $this->tag->getId() . ' does not exist');
@@ -151,11 +154,15 @@ public function update($name, $userVisible, $userAssignable) {
 	/**
 	 * Returns null, not supported
 	 *
+	 * @return null
 	 */
 	public function getLastModified() {
 		return null;
 	}
 
+	/**
+	 * @return void
+	 */
 	public function delete() {
 		try {
 			if (!$this->isAdmin) {

apps/dav/lib/SystemTag/SystemTagPlugin.php

@@ -25,10 +25,14 @@
  */
 namespace OCA\DAV\SystemTag;
 
+use OCA\DAV\Connector\Sabre\Directory;
+use OCA\DAV\Connector\Sabre\Node;
 use OCP\IGroupManager;
+use OCP\IUser;
 use OCP\IUserSession;
 use OCP\SystemTag\ISystemTag;
 use OCP\SystemTag\ISystemTagManager;
+use OCP\SystemTag\ISystemTagObjectMapper;
 use OCP\SystemTag\TagAlreadyExistsException;
 use Sabre\DAV\Exception\BadRequest;
 use Sabre\DAV\Exception\Conflict;
@@ -56,6 +60,7 @@ class SystemTagPlugin extends \Sabre\DAV\ServerPlugin {
 	public const USERASSIGNABLE_PROPERTYNAME = '{http://owncloud.org/ns}user-assignable';
 	public const GROUPS_PROPERTYNAME = '{http://owncloud.org/ns}groups';
 	public const CANASSIGN_PROPERTYNAME = '{http://owncloud.org/ns}can-assign';
+	public const SYSTEM_TAGS_PROPERTYNAME = '{http://nextcloud.org/ns}system-tags';
 
 	/**
 	 * @var \Sabre\DAV\Server $server
@@ -77,17 +82,23 @@ class SystemTagPlugin extends \Sabre\DAV\ServerPlugin {
 	 */
 	protected $groupManager;
 
-	/**
-	 * @param ISystemTagManager $tagManager tag manager
-	 * @param IGroupManager $groupManager
-	 * @param IUserSession $userSession
-	 */
-	public function __construct(ISystemTagManager $tagManager,
-								IGroupManager $groupManager,
-								IUserSession $userSession) {
+	/** @var array<int, string[]> */
+	private array $cachedTagMappings = [];
+	/** @var array<string, ISystemTag> */
+	private array $cachedTags = [];
+
+	private ISystemTagObjectMapper $tagMapper;
+
+	public function __construct(
+		ISystemTagManager $tagManager,
+		IGroupManager $groupManager,
+		IUserSession $userSession,
+		ISystemTagObjectMapper $tagMapper,
+	) {
 		$this->tagManager = $tagManager;
 		$this->userSession = $userSession;
 		$this->groupManager = $groupManager;
+		$this->tagMapper = $tagMapper;
 	}
 
 	/**
@@ -215,11 +226,18 @@ private function createTag($data, $contentType = 'application/json') {
 	 *
 	 * @param PropFind $propFind
 	 * @param \Sabre\DAV\INode $node
+	 *
+	 * @return void
 	 */
 	public function handleGetProperties(
 		PropFind $propFind,
 		\Sabre\DAV\INode $node
 	) {
+		if ($node instanceof Node) {
+			$this->propfindForFile($propFind, $node);
+			return;
+		}
+
 		if (!($node instanceof SystemTagNode) && !($node instanceof SystemTagMappingNode)) {
 			return;
 		}
@@ -260,6 +278,79 @@ public function handleGetProperties(
 		});
 	}
 
+	private function propfindForFile(PropFind $propFind, Node $node): void {
+		if ($node instanceof Directory
+			&& $propFind->getDepth() !== 0
+			&& !is_null($propFind->getStatus(self::SYSTEM_TAGS_PROPERTYNAME))) {
+			$fileIds = [$node->getId()];
+
+			// note: pre-fetching only supported for depth <= 1
+			$folderContent = $node->getNode()->getDirectoryListing();
+			foreach ($folderContent as $info) {
+				$fileIds[] = $info->getId();
+			}
+
+			$tags = $this->tagMapper->getTagIdsForObjects($fileIds, 'files');
+
+			$this->cachedTagMappings = $this->cachedTagMappings + $tags;
+			$emptyFileIds = array_diff($fileIds, array_keys($tags));
+
+			// also cache the ones that were not found
+			foreach ($emptyFileIds as $fileId) {
+				$this->cachedTagMappings[$fileId] = [];
+			}
+		}
+
+		$propFind->handle(self::SYSTEM_TAGS_PROPERTYNAME, function () use ($node) {
+			$user = $this->userSession->getUser();
+			if ($user === null) {
+				return;
+			}
+
+			$tags = $this->getTagsForFile($node->getId(), $user);
+			return new SystemTagList($tags, $this->tagManager, $user);
+		});
+	}
+
+	/**
+	 * @param int $fileId
+	 * @return ISystemTag[]
+	 */
+	private function getTagsForFile(int $fileId, IUser $user): array {
+
+		if (isset($this->cachedTagMappings[$fileId])) {
+			$tagIds = $this->cachedTagMappings[$fileId];
+		} else {
+			$tags = $this->tagMapper->getTagIdsForObjects([$fileId], 'files');
+			$fileTags = current($tags);
+			if ($fileTags) {
+				$tagIds = $fileTags;
+			} else {
+				$tagIds = [];
+			}
+		}
+
+		$tags = array_filter(array_map(function(string $tagId) {
+			return $this->cachedTags[$tagId] ?? null;
+		}, $tagIds));
+
+		$uncachedTagIds = array_filter($tagIds, function(string $tagId): bool {
+			return !isset($this->cachedTags[$tagId]);
+		});
+
+		if (count($uncachedTagIds)) {
+			$retrievedTags = $this->tagManager->getTagsByIds($uncachedTagIds);
+			foreach ($retrievedTags as $tag) {
+				$this->cachedTags[$tag->getId()] = $tag;
+			}
+			$tags += $retrievedTags;
+		}
+
+		return array_filter($tags, function(ISystemTag $tag) use ($user) {
+			return $this->tagManager->canUserSeeTag($tag, $user);
+		});
+	}
+
 	/**
 	 * Updates tag attributes
 	 *

apps/dav/lib/SystemTag/SystemTagsByIdCollection.php

@@ -84,21 +84,28 @@ private function isAdmin() {
 	/**
 	 * @param string $name
 	 * @param resource|string $data Initial payload
+	 *
 	 * @throws Forbidden
+	 *
+	 * @return never
 	 */
 	public function createFile($name, $data = null) {
 		throw new Forbidden('Cannot create tags by id');
 	}
 
 	/**
 	 * @param string $name
+	 *
+	 * @return never
 	 */
 	public function createDirectory($name) {
 		throw new Forbidden('Permission denied to create collections');
 	}
 
 	/**
 	 * @param string $name
+	 *
+	 * @return SystemTagNode
 	 */
 	public function getChild($name) {
 		try {
@@ -115,6 +122,11 @@ public function getChild($name) {
 		}
 	}
 
+	/**
+	 * @return SystemTagNode[]
+	 *
+	 * @psalm-return array<SystemTagNode>
+	 */
 	public function getChildren() {
 		$visibilityFilter = true;
 		if ($this->isAdmin()) {
@@ -145,22 +157,33 @@ public function childExists($name) {
 		}
 	}
 
+	/**
+	 * @return never
+	 */
 	public function delete() {
 		throw new Forbidden('Permission denied to delete this collection');
 	}
 
+	/**
+	 * @return string
+	 *
+	 * @psalm-return 'systemtags'
+	 */
 	public function getName() {
 		return 'systemtags';
 	}
 
+	/**
+	 * @return never
+	 */
 	public function setName($name) {
 		throw new Forbidden('Permission denied to rename this collection');
 	}
 
 	/**
 	 * Returns the last modification time, as a unix timestamp
 	 *
-	 * @return int
+	 * @return null
 	 */
 	public function getLastModified() {
 		return null;