OC_VCategories=>OC\Tags. Public interface + getter in server container

5 files changed, 813 insertions, 833 deletions

diff --git a/lib/public/iservercontainer.php b/lib/public/iservercontainer.php
index d88330698dc..e44acee6533 100644
--- a/lib/public/iservercontainer.php
+++ b/lib/public/iservercontainer.php
@@ -56,6 +56,13 @@ interface IServerContainer {
 	function getPreviewManager();
 
 	/**
+	 * Returns the tag manager which can get and set tags for different object types
+	 *
+	 * @return \OCP\ITags
+	 */
+	function getTagManager();
+
+	/**
 	 * Returns the root folder of ownCloud's data directory
 	 *
 	 * @return \OCP\Files\Folder
diff --git a/lib/public/itags.php b/lib/public/itags.php
new file mode 100644
index 00000000000..047d4f5f40b
--- /dev/null
+++ b/lib/public/itags.php
@@ -0,0 +1,173 @@
+<?php
+/**
+* ownCloud
+*
+* @author Thomas Tanghus
+* @copyright 2013 Thomas Tanghus <thomas@tanghus.net>
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+* License as published by the Free Software Foundation; either
+* version 3 of the License, or any later version.
+*
+* This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
+*
+*/
+
+namespace OCP;
+
+// FIXME: Where should I put this? Or should it be implemented as a Listener?
+\OC_Hook::connect('OC_User', 'post_deleteUser', 'OC\Tags', 'post_deleteUser');
+
+/**
+ * Class for easily tagging objects by their id
+ *
+ * A tag can be e.g. 'Family', 'Work', 'Chore', 'Special Occation' or
+ * anything else that is either parsed from a vobject or that the user chooses
+ * to add.
+ * Tag names are not case-sensitive, but will be saved with the case they
+ * are entered in. If a user already has a tag 'family' for a type, and
+ * tries to add a tag named 'Family' it will be silently ignored.
+ */
+
+interface ITags {
+
+	/**
+	* Load tags from db.
+	*
+	* @param string $type The type identifier e.g. 'contact' or 'event'.
+	* @param array $defaultTags An array of default tags to be used if none are stored.
+	* @return \OCP\ITags
+	*/
+	public function loadTagsFor($type, $defaultTags=array());
+
+	/**
+	* Check if any tags are saved for this type and user.
+	*
+	* @return boolean.
+	*/
+	public function isEmpty();
+
+	/**
+	* Get the tags for a specific user.
+	*
+	* This returns an array with id/name maps:
+	* [
+	* 	['id' => 0, 'name' = 'First tag'],
+	* 	['id' => 1, 'name' = 'Second tag'],
+	* ]
+	*
+	* @returns array
+	*/
+	public function tags();
+
+	/**
+	* Get the a list if items tagged with $tag.
+	*
+	* Throws an exception if the tag could not be found.
+	*
+	* @param string|integer $tag Tag id or name.
+	* @return array An array of object ids or false on error.
+	*/
+	public function idsForTag($tag);
+
+	/**
+	* Checks whether a tag is already saved.
+	*
+	* @param string $name The name to check for.
+	* @return bool
+	*/
+	public function hasTag($name);
+
+	/**
+	* Add a new tag.
+	*
+	* @param string $name A string with a name of the tag
+	* @return int the id of the added tag or false if it already exists.
+	*/
+	public function add($name);
+
+	/**
+	* Rename tag.
+	*
+	* @param string $from The name of the existing tag
+	* @param string $to The new name of the tag.
+	* @return bool
+	*/
+	public function rename($from, $to);
+
+	/**
+	* Add a list of new tags.
+	*
+	* @param string[] $names A string with a name or an array of strings containing
+	* the name(s) of the to add.
+	* @param bool $sync When true, save the tags
+	* @param int|null $id int Optional object id to add to this|these tag(s)
+	* @return bool Returns false on error.
+	*/
+	public function addMulti($names, $sync=false, $id = null);
+
+	/**
+	* Delete tag/object relations from the db
+	*
+	* @param array $ids The ids of the objects
+	* @return boolean Returns false on error.
+	*/
+	public function purgeObjects(array $ids);
+
+	/**
+	* Get favorites for an object type
+	*
+	* @return array An array of object ids.
+	*/
+	public function getFavorites();
+
+	/**
+	* Add an object to favorites
+	*
+	* @param int $objid The id of the object
+	* @return boolean
+	*/
+	public function addToFavorites($objid);
+
+	/**
+	* Remove an object from favorites
+	*
+	* @param int $objid The id of the object
+	* @return boolean
+	*/
+	public function removeFromFavorites($objid);
+
+	/**
+	* Creates a tag/object relation.
+	*
+	* @param int $objid The id of the object
+	* @param int|string $tag The id or name of the tag
+	* @return boolean Returns false on database error.
+	*/
+	public function tagAs($objid, $tag);
+
+	/**
+	* Delete single tag/object relation from the db
+	*
+	* @param int $objid The id of the object
+	* @param int|string $tag The id or name of the tag
+	* @return boolean
+	*/
+	public function unTag($objid, $tag);
+
+	/**
+	* Delete tags from the
+	*
+	* @param string[] $names An array of tags to delete
+	* @return bool Returns false on error
+	*/
+	public function delete($names);
+
+}
\ No newline at end of file
diff --git a/lib/server.php b/lib/server.php
index 9e87bd3190d..f25216b746d 100644
--- a/lib/server.php
+++ b/lib/server.php
@@ -49,6 +49,9 @@ class Server extends SimpleContainer implements IServerContainer {
 		$this->registerService('PreviewManager', function($c){
 			return new PreviewManager();
 		});
+		$this->registerService('TagManager', function($c){
+			return new Tags();
+		});
 		$this->registerService('RootFolder', function($c){
 			// TODO: get user and user manager from container as well
 			$user = \OC_User::getUser();
@@ -89,6 +92,15 @@ class Server extends SimpleContainer implements IServerContainer {
 	}
 
 	/**
+	 * Returns the tag manager which can get and set tags for different object types
+	 *
+	 * @return \OCP\ITags
+	 */
+	function getTagManager() {
+		return $this->query('TagManager');
+	}
+
+	/**
 	 * Returns the root folder of ownCloud's data directory
 	 *
 	 * @return \OCP\Files\Folder
diff --git a/lib/tags.php b/lib/tags.php
new file mode 100644
index 00000000000..4aafff8e1bb
--- /dev/null
+++ b/lib/tags.php
@@ -0,0 +1,621 @@
+<?php
+/**
+* ownCloud
+*
+* @author Thomas Tanghus
+* @copyright 2012-2013 Thomas Tanghus <thomas@tanghus.net>
+* @copyright 2012 Bart Visscher bartv@thisnet.nl
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+* License as published by the Free Software Foundation; either
+* version 3 of the License, or any later version.
+*
+* This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
+*
+*/
+
+/**
+ * Class for easily tagging objects by their id
+ *
+ * A tag can be e.g. 'Family', 'Work', 'Chore', 'Special Occation' or
+ * anything else that is either parsed from a vobject or that the user chooses
+ * to add.
+ * Tag names are not case-sensitive, but will be saved with the case they
+ * are entered in. If a user already has a tag 'family' for a type, and
+ * tries to add a tag named 'Family' it will be silently ignored.
+ */
+
+namespace OC;
+
+class Tags implements \OCP\ITags {
+
+	/**
+	 * Tags
+	 */
+	private $tags = array();
+
+	/**
+	 * Used for storing objectid/categoryname pairs while rescanning.
+	 */
+	private static $relations = array();
+
+	private $type = null;
+	private $user = null;
+
+	const TAG_TABLE = '*PREFIX*vcategory';
+	const RELATION_TABLE = '*PREFIX*vcategory_to_object';
+
+	const TAG_FAVORITE = '_$!<Favorite>!$_';
+
+	/**
+	* Constructor.
+	*
+	* @param string $user The user whos data the object will operate on.
+	*/
+	public function __construct($user) {
+
+		$this->user = $user;
+
+	}
+
+	/**
+	* Load tags from db.
+	*
+	* @param string $type The type identifier e.g. 'contact' or 'event'.
+	* @param array $defaultTags An array of default tags to be used if none are stored.
+	* @return \OCP\ITags
+	*/
+	public function loadTagsFor($type, $defaultTags=array()) {
+		$this->type = $type;
+		$this->tags = array();
+		$result = null;
+		$sql = 'SELECT `id`, `category` FROM `' . self::TAG_TABLE . '` '
+			. 'WHERE `uid` = ? AND `type` = ? ORDER BY `category`';
+		try {
+			$stmt = \OCP\DB::prepare($sql);
+			$result = $stmt->execute(array($this->user, $this->type));
+			if (\OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. ', DB error: ' . \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+			}
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+		}
+
+		if(!is_null($result)) {
+			while( $row = $result->fetchRow()) {
+				$this->tags[$row['id']] = $row['category'];
+			}
+		}
+
+		if(count($defaultTags) > 0 && count($this->tags) === 0) {
+			$this->addMulti($defaultTags, true);
+		}
+		\OCP\Util::writeLog('core', __METHOD__.', tags: ' . print_r($this->tags, true),
+			\OCP\Util::DEBUG);
+
+		return $this;
+	}
+
+	/**
+	* Check if any tags are saved for this type and user.
+	*
+	* @return boolean.
+	*/
+	public function isEmpty() {
+		$sql = 'SELECT COUNT(*) FROM `' . self::TAG_TABLE . '` '
+			. 'WHERE `uid` = ? AND `type` = ?';
+		try {
+			$stmt = OCP\DB::prepare($sql);
+			$result = $stmt->execute(array($this->user, $this->type));
+			if (\OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. ', DB error: ' . \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+				return false;
+			}
+			return ($result->numRows() === 0);
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+			return false;
+		}
+	}
+
+	/**
+	* Get the tags for a specific user.
+	*
+	* This returns an array with id/name maps:
+	* [
+	* 	['id' => 0, 'name' = 'First tag'],
+	* 	['id' => 1, 'name' = 'Second tag'],
+	* ]
+	*
+	* @return array
+	*/
+	public function tags() {
+		if(!count($this->tags)) {
+			return array();
+		}
+
+		$tags = array_values($this->tags);
+		uasort($tags, 'strnatcasecmp');
+		$tagMap = array();
+
+		foreach($tags as $tag) {
+			if($tag !== self::TAG_FAVORITE) {
+				$tagMap[] = array(
+					'id' => $this->array_searchi($tag, $this->tags),
+					'name' => $tag
+					);
+			}
+		}
+		return $tagMap;
+
+	}
+
+	/**
+	* Get the a list if items tagged with $tag.
+	*
+	* Throws an exception if the tag could not be found.
+	*
+	* @param string|integer $tag Tag id or name.
+	* @return array An array of object ids or false on error.
+	*/
+	public function idsForTag($tag) {
+		$result = null;
+		if(is_numeric($tag)) {
+			$tagId = $tag;
+		} elseif(is_string($tag)) {
+			$tag = trim($tag);
+			$tagId = $this->array_searchi($tag, $this->tags);
+		}
+
+		if($tagId === false) {
+			$l10n = \OC_L10N::get('core');
+			throw new \Exception(
+				$l10n->t('Could not find category "%s"', $tag)
+			);
+		}
+
+		$ids = array();
+		$sql = 'SELECT `objid` FROM `' . self::RELATION_TABLE
+			. '` WHERE `categoryid` = ?';
+
+		try {
+			$stmt = \OCP\DB::prepare($sql);
+			$result = $stmt->execute(array($tagId));
+			if (\OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+				return false;
+			}
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+			return false;
+		}
+
+		if(!is_null($result)) {
+			while( $row = $result->fetchRow()) {
+				$ids[] = (int)$row['objid'];
+			}
+		}
+
+		return $ids;
+	}
+
+	/**
+	* Checks whether a tag is already saved.
+	*
+	* @param string $name The name to check for.
+	* @return bool
+	*/
+	public function hasTag($name) {
+		return $this->in_arrayi($name, $this->tags);
+	}
+
+	/**
+	* Add a new tag.
+	*
+	* @param string $name A string with a name of the tag
+	* @return int the id of the added tag or false if it already exists.
+	*/
+	public function add($name) {
+		$name = trim($name);
+
+		if($this->hasTag($name)) {
+			\OCP\Util::writeLog('core', __METHOD__.', name: ' . $name. ' exists already', \OCP\Util::DEBUG);
+			return false;
+		}
+		try {
+			\OCP\DB::insertIfNotExist(self::TAG_TABLE,
+				array(
+					'uid' => $this->user,
+					'type' => $this->type,
+					'category' => $name,
+				));
+			} catch(\Exception $e) {
+				\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+					\OCP\Util::ERROR);
+				return false;
+			}
+		$id = \OCP\DB::insertid(self::TAG_TABLE);
+		\OCP\Util::writeLog('core', __METHOD__.', id: ' . $id, \OCP\Util::DEBUG);
+		$this->tags[$id] = $name;
+		return $id;
+	}
+
+	/**
+	* Rename tag.
+	*
+	* @param string $from The name of the existing tag
+	* @param string $to The new name of the tag.
+	* @return bool
+	*/
+	public function rename($from, $to) {
+		$from = trim($from);
+		$to = trim($to);
+		$id = $this->array_searchi($from, $this->tags);
+		if($id === false) {
+			\OCP\Util::writeLog('core', __METHOD__.', tag: ' . $from. ' does not exist', \OCP\Util::DEBUG);
+			return false;
+		}
+
+		$sql = 'UPDATE `' . self::TAG_TABLE . '` SET `category` = ? '
+			. 'WHERE `uid` = ? AND `type` = ? AND `id` = ?';
+		try {
+			$stmt = \OCP\DB::prepare($sql);
+			$result = $stmt->execute(array($to, $this->user, $this->type, $id));
+			if (\OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+				return false;
+			}
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+			return false;
+		}
+		$this->tags[$id] = $to;
+		return true;
+	}
+
+	/**
+	* Add a list of new tags.
+	*
+	* @param string[] $names A string with a name or an array of strings containing
+	* the name(s) of the to add.
+	* @param bool $sync When true, save the tags
+	* @param int|null $id int Optional object id to add to this|these tag(s)
+	* @return bool Returns false on error.
+	*/
+	public function addMulti($names, $sync=false, $id = null) {
+		if(!is_array($names)) {
+			$names = array($names);
+		}
+		$names = array_map('trim', $names);
+		$newones = array();
+		foreach($names as $name) {
+			if(($this->in_arrayi(
+				$name, $this->tags) == false) && $name !== '') {
+				$newones[] = $name;
+			}
+			if(!is_null($id) ) {
+				// Insert $objectid, $categoryid  pairs if not exist.
+				self::$relations[] = array('objid' => $id, 'tag' => $name);
+			}
+		}
+		$this->tags = array_merge($this->tags, $newones);
+		if($sync === true) {
+			$this->save();
+		}
+
+		return true;
+	}
+
+	/**
+	 * Save the list of tags and their object relations
+	 */
+	protected function save() {
+		if(is_array($this->tags)) {
+			foreach($this->tags as $tag) {
+				try {
+					\OCP\DB::insertIfNotExist(self::TAG_TABLE,
+						array(
+							'uid' => $this->user,
+							'type' => $this->type,
+							'category' => $tag,
+						));
+				} catch(\Exception $e) {
+					\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+						\OCP\Util::ERROR);
+				}
+			}
+			// reload tags to get the proper ids.
+			$this->loadTagsFor($this->type);
+			// Loop through temporarily cached objectid/tagname pairs
+			// and save relations.
+			$tags = $this->tags;
+			// For some reason this is needed or array_search(i) will return 0..?
+			ksort($tags);
+			foreach(self::$relations as $relation) {
+				$tagId = $this->array_searchi($relation['tag'], $tags);
+				\OCP\Util::writeLog('core', __METHOD__ . 'catid, ' . $relation['tag'] . ' ' . $tagId, \OCP\Util::DEBUG);
+				if($tagId) {
+					try {
+						\OCP\DB::insertIfNotExist(self::RELATION_TABLE,
+							array(
+								'objid' => $relation['objid'],
+								'categoryid' => $tagId,
+								'type' => $this->type,
+								));
+					} catch(\Exception $e) {
+						\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+							\OCP\Util::ERROR);
+					}
+				}
+			}
+			self::$relations = array(); // reset
+		} else {
+			\OCP\Util::writeLog('core', __METHOD__.', $this->tags is not an array! '
+				. print_r($this->tags, true), \OCP\Util::ERROR);
+		}
+	}
+
+	/**
+	* Delete tags and tag/object relations for a user.
+	*
+	* For hooking up on post_deleteUser
+	*
+	* @param array
+	*/
+	public static function post_deleteUser($arguments) {
+		// Find all objectid/tagId pairs.
+		$result = null;
+		try {
+			$stmt = \OCP\DB::prepare('SELECT `id` FROM `' . self::TAG_TABLE . '` '
+				. 'WHERE `uid` = ?');
+			$result = $stmt->execute(array($arguments['uid']));
+			if (\OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+			}
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+		}
+
+		if(!is_null($result)) {
+			try {
+				$stmt = \OCP\DB::prepare('DELETE FROM `' . self::RELATION_TABLE . '` '
+					. 'WHERE `categoryid` = ?');
+				while( $row = $result->fetchRow()) {
+					try {
+						$stmt->execute(array($row['id']));
+					} catch(\Exception $e) {
+						\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+							\OCP\Util::ERROR);
+					}
+				}
+			} catch(\Exception $e) {
+				\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+					\OCP\Util::ERROR);
+			}
+		}
+		try {
+			$stmt = \OCP\DB::prepare('DELETE FROM `' . self::TAG_TABLE . '` '
+				. 'WHERE `uid` = ?');
+			$result = $stmt->execute(array($arguments['uid']));
+			if (OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. ', DB error: ' . \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+			}
+		} catch(\Exception $e) {
+			OCP\Util::writeLog('core', __METHOD__ . ', exception: '
+				. $e->getMessage(), OCP\Util::ERROR);
+		}
+	}
+
+	/**
+	* Delete tag/object relations from the db
+	*
+	* @param array $ids The ids of the objects
+	* @return boolean Returns false on error.
+	*/
+	public function purgeObjects(array $ids) {
+		if(count($ids) === 0) {
+			// job done ;)
+			return true;
+		}
+		$updates = $ids;
+		try {
+			$query = 'DELETE FROM `' . self::RELATION_TABLE . '` ';
+			$query .= 'WHERE `objid` IN (' . str_repeat('?,', count($ids)-1) . '?) ';
+			$query .= 'AND `type`= ?';
+			$updates[] = $this->type;
+			$stmt = OCP\DB::prepare($query);
+			$result = $stmt->execute($updates);
+			if (\OCP\DB::isError($result)) {
+				\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . \OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+				return false;
+			}
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: ' . $e->getMessage(),
+				\OCP\Util::ERROR);
+			return false;
+		}
+		return true;
+	}
+
+	/**
+	* Get favorites for an object type
+	*
+	* @return array An array of object ids.
+	*/
+	public function getFavorites() {
+		try {
+			return $this->idsForTag(self::TAG_FAVORITE);
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: ' . $e->getMessage(),
+				\OCP\Util::ERROR);
+			return array();
+		}
+	}
+
+	/**
+	* Add an object to favorites
+	*
+	* @param int $objid The id of the object
+	* @return boolean
+	*/
+	public function addToFavorites($objid) {
+		if(!$this->hasCategory(self::TAG_FAVORITE)) {
+			$this->add(self::TAG_FAVORITE, true);
+		}
+		return $this->tagAs($objid, self::TAG_FAVORITE, $this->type);
+	}
+
+	/**
+	* Remove an object from favorites
+	*
+	* @param int $objid The id of the object
+	* @return boolean
+	*/
+	public function removeFromFavorites($objid) {
+		return $this->unTag($objid, self::TAG_FAVORITE, $this->type);
+	}
+
+	/**
+	* Creates a tag/object relation.
+	*
+	* @param int $objid The id of the object
+	* @param int|string $tag The id or name of the tag
+	* @return boolean Returns false on database error.
+	*/
+	public function tagAs($objid, $tag) {
+		if(is_string($tag) && !is_numeric($tag)) {
+			$tag = trim($tag);
+			if(!$this->hasTag($tag)) {
+				$this->add($tag, true);
+			}
+			$tagId =  $this->array_searchi($tag, $this->tags);
+		} else {
+			$tagId = $tag;
+		}
+		try {
+			\OCP\DB::insertIfNotExist(self::RELATION_TABLE,
+				array(
+					'objid' => $objid,
+					'categoryid' => $tagId,
+					'type' => $this->type,
+				));
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+			return false;
+		}
+		return true;
+	}
+
+	/**
+	* Delete single tag/object relation from the db
+	*
+	* @param int $objid The id of the object
+	* @param int|string $tag The id or name of the tag
+	* @return boolean
+	*/
+	public function unTag($objid, $tag) {
+		if(is_string($tag) && !is_numeric($tag)) {
+			$tag = trim($tag);
+			$tagId =  $this->array_searchi($tag, $this->tags);
+		} else {
+			$tagId = $tag;
+		}
+
+		try {
+			$sql = 'DELETE FROM `' . self::RELATION_TABLE . '` '
+					. 'WHERE `objid` = ? AND `categoryid` = ? AND `type` = ?';
+			$stmt = \OCP\DB::prepare($sql);
+			$stmt->execute(array($objid, $tagId, $this->type));
+		} catch(\Exception $e) {
+			\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+				\OCP\Util::ERROR);
+			return false;
+		}
+		return true;
+	}
+
+	/**
+	* Delete tags from the
+	*
+	* @param string[] $names An array of tags to delete
+	* @return bool Returns false on error
+	*/
+	public function delete($names) {
+		if(!is_array($names)) {
+			$names = array($names);
+		}
+
+		$names = array_map('trim', $names);
+
+		\OCP\Util::writeLog('core', __METHOD__ . ', before: '
+			. print_r($this->tags, true), \OCP\Util::DEBUG);
+		foreach($names as $name) {
+			$id = null;
+
+			if($this->hasTag($name)) {
+				$id = $this->array_searchi($name, $this->tags);
+				unset($this->tags[$id]);
+			}
+			try {
+				$stmt = \OCP\DB::prepare('DELETE FROM `' . self::TAG_TABLE . '` WHERE '
+					. '`uid` = ? AND `type` = ? AND `category` = ?');
+				$result = $stmt->execute(array($this->user, $this->type, $name));
+				if (\OCP\DB::isError($result)) {
+					\OCP\Util::writeLog('core', __METHOD__. 'DB error: ' . OCP\DB::getErrorMessage($result), \OCP\Util::ERROR);
+				}
+			} catch(\Exception $e) {
+				\OCP\Util::writeLog('core', __METHOD__ . ', exception: '
+					. $e->getMessage(), \OCP\Util::ERROR);
+				return false;
+			}
+			if(!is_null($id) && $id !== false) {
+				try {
+					$sql = 'DELETE FROM `' . self::RELATION_TABLE . '` '
+							. 'WHERE `categoryid` = ?';
+					$stmt = \OCP\DB::prepare($sql);
+					$result = $stmt->execute(array($id));
+					if (\OCP\DB::isError($result)) {
+						\OCP\Util::writeLog('core',
+							__METHOD__. 'DB error: ' . \OCP\DB::getErrorMessage($result),
+							\OCP\Util::ERROR);
+						return false;
+					}
+				} catch(\Exception $e) {
+					\OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
+						\OCP\Util::ERROR);
+					return false;
+				}
+			}
+		}
+		return true;
+	}
+
+	// case-insensitive in_array
+	private function in_arrayi($needle, $haystack) {
+		if(!is_array($haystack)) {
+			return false;
+		}
+		return in_array(strtolower($needle), array_map('strtolower', $haystack));
+	}
+
+	// case-insensitive array_search
+	private function array_searchi($needle, $haystack) {
+		if(!is_array($haystack)) {
+			return false;
+		}
+		return array_search(strtolower($needle), array_map('strtolower', $haystack));
+	}
+}
diff --git a/lib/vcategories.php b/lib/vcategories.php
deleted file mode 100644
index a7e4c54be29..00000000000
--- a/lib/vcategories.php
+++ /dev/null
@@ -1,833 +0,0 @@
-<?php
-/**
-* ownCloud
-*
-* @author Thomas Tanghus
-* @copyright 2012 Thomas Tanghus <thomas@tanghus.net>
-* @copyright 2012 Bart Visscher bartv@thisnet.nl
-*
-* This library is free software; you can redistribute it and/or
-* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
-* License as published by the Free Software Foundation; either
-* version 3 of the License, or any later version.
-*
-* This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
-*
-*/
-
-OC_Hook::connect('OC_User', 'post_deleteUser', 'OC_VCategories', 'post_deleteUser');
-
-/**
- * Class for easy access to categories in VCARD, VEVENT, VTODO and VJOURNAL.
- * A Category can be e.g. 'Family', 'Work', 'Chore', 'Special Occation' or
- * anything else that is either parsed from a vobject or that the user chooses
- * to add.
- * Category names are not case-sensitive, but will be saved with the case they
- * are entered in. If a user already has a category 'family' for a type, and
- * tries to add a category named 'Family' it will be silently ignored.
- */
-class OC_VCategories {
-
-	/**
-	 * Categories
-	 */
-	private $categories = array();
-
-	/**
-	 * Used for storing objectid/categoryname pairs while rescanning.
-	 */
-	private static $relations = array();
-
-	private $type = null;
-	private $user = null;
-
-	const CATEGORY_TABLE = '*PREFIX*vcategory';
-	const RELATION_TABLE = '*PREFIX*vcategory_to_object';
-
-	const CATEGORY_FAVORITE = '_$!<Favorite>!$_';
-
-	const FORMAT_LIST = 0;
-	const FORMAT_MAP  = 1;
-
-	/**
-	* @brief Constructor.
-	* @param $type The type identifier e.g. 'contact' or 'event'.
-	* @param $user The user whos data the object will operate on. This
-	*   parameter should normally be omitted but to make an app able to
-	*   update categories for all users it is made possible to provide it.
-	* @param $defcategories An array of default categories to be used if none is stored.
-	*/
-	public function __construct($type, $user=null, $defcategories=array()) {
-		$this->type = $type;
-		$this->user = is_null($user) ? OC_User::getUser() : $user;
-
-		$this->loadCategories();
-		OCP\Util::writeLog('core', __METHOD__ . ', categories: '
-			. print_r($this->categories, true),
-			OCP\Util::DEBUG
-		);
-
-		if($defcategories && count($this->categories) === 0) {
-			$this->addMulti($defcategories, true);
-		}
-	}
-
-	/**
-	* @brief Load categories from db.
-	*/
-	private function loadCategories() {
-		$this->categories = array();
-		$result = null;
-		$sql = 'SELECT `id`, `category` FROM `' . self::CATEGORY_TABLE . '` '
-			. 'WHERE `uid` = ? AND `type` = ? ORDER BY `category`';
-		try {
-			$stmt = OCP\DB::prepare($sql);
-			$result = $stmt->execute(array($this->user, $this->type));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-		}
-
-		if(!is_null($result)) {
-			while( $row = $result->fetchRow()) {
-				// The keys are prefixed because array_search wouldn't work otherwise :-/
-				$this->categories[$row['id']] = $row['category'];
-			}
-		}
-		OCP\Util::writeLog('core', __METHOD__.', categories: ' . print_r($this->categories, true),
-			OCP\Util::DEBUG);
-	}
-
-
-	/**
-	* @brief Check if any categories are saved for this type and user.
-	* @returns boolean.
-	* @param $type The type identifier e.g. 'contact' or 'event'.
-	* @param $user The user whos categories will be checked. If not set current user will be used.
-	*/
-	public static function isEmpty($type, $user = null) {
-		$user = is_null($user) ? OC_User::getUser() : $user;
-		$sql = 'SELECT COUNT(*) FROM `' . self::CATEGORY_TABLE . '` '
-			. 'WHERE `uid` = ? AND `type` = ?';
-		try {
-			$stmt = OCP\DB::prepare($sql);
-			$result = $stmt->execute(array($user, $type));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-				return false;
-			}
-			return ($result->numRows() === 0);
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-	}
-
-	/**
-	* @brief Get the categories for a specific user.
-	* @param
-	* @returns array containing the categories as strings.
-	*/
-	public function categories($format = null) {
-		if(!$this->categories) {
-			return array();
-		}
-		$categories = array_values($this->categories);
-		uasort($categories, 'strnatcasecmp');
-		if($format == self::FORMAT_MAP) {
-			$catmap = array();
-			foreach($categories as $category) {
-				if($category !== self::CATEGORY_FAVORITE) {
-					$catmap[] = array(
-						'id' => $this->array_searchi($category, $this->categories),
-						'name' => $category
-						);
-				}
-			}
-			return $catmap;
-		}
-
-		// Don't add favorites to normal categories.
-		$favpos = array_search(self::CATEGORY_FAVORITE, $categories);
-		if($favpos !== false) {
-			return array_splice($categories, $favpos);
-		} else {
-			return $categories;
-		}
-	}
-
-	/**
-	* Get the a list if items belonging to $category.
-	*
-	* Throws an exception if the category could not be found.
-	*
-	* @param string|integer $category Category id or name.
-	* @returns array An array of object ids or false on error.
-	*/
-	public function idsForCategory($category) {
-		$result = null;
-		if(is_numeric($category)) {
-			$catid = $category;
-		} elseif(is_string($category)) {
-			$category = trim($category);
-			$catid = $this->array_searchi($category, $this->categories);
-		}
-		OCP\Util::writeLog('core', __METHOD__.', category: '.$catid.' '.$category, OCP\Util::DEBUG);
-		if($catid === false) {
-			$l10n = OC_L10N::get('core');
-			throw new Exception(
-				$l10n->t('Could not find category "%s"', $category)
-			);
-		}
-
-		$ids = array();
-		$sql = 'SELECT `objid` FROM `' . self::RELATION_TABLE
-			. '` WHERE `categoryid` = ?';
-
-		try {
-			$stmt = OCP\DB::prepare($sql);
-			$result = $stmt->execute(array($catid));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-				return false;
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-
-		if(!is_null($result)) {
-			while( $row = $result->fetchRow()) {
-				$ids[] = (int)$row['objid'];
-			}
-		}
-
-		return $ids;
-	}
-
-	/**
-	* Get the a list if items belonging to $category.
-	*
-	* Throws an exception if the category could not be found.
-	*
-	* @param string|integer $category Category id or name.
-	* @param array $tableinfo Array in the form {'tablename' => table, 'fields' => ['field1', 'field2']}
-	* @param int $limit
-	* @param int $offset
-	*
-	* This generic method queries a table assuming that the id
-	* field is called 'id' and the table name provided is in
-	* the form '*PREFIX*table_name'.
-	*
-	* If the category name cannot be resolved an exception is thrown.
-	*
-	* TODO: Maybe add the getting permissions for objects?
-	*
-	* @returns array containing the resulting items or false on error.
-	*/
-	public function itemsForCategory($category, $tableinfo, $limit = null, $offset = null) {
-		$result = null;
-		if(is_numeric($category)) {
-			$catid = $category;
-		} elseif(is_string($category)) {
-			$category = trim($category);
-			$catid = $this->array_searchi($category, $this->categories);
-		}
-		OCP\Util::writeLog('core', __METHOD__.', category: '.$catid.' '.$category, OCP\Util::DEBUG);
-		if($catid === false) {
-			$l10n = OC_L10N::get('core');
-			throw new Exception(
-				$l10n->t('Could not find category "%s"', $category)
-			);
-		}
-		$fields = '';
-		foreach($tableinfo['fields'] as $field) {
-			$fields .= '`' . $tableinfo['tablename'] . '`.`' . $field . '`,';
-		}
-		$fields = substr($fields, 0, -1);
-
-		$items = array();
-		$sql = 'SELECT `' . self::RELATION_TABLE . '`.`categoryid`, ' . $fields
-			. ' FROM `' . $tableinfo['tablename'] . '` JOIN `'
-			. self::RELATION_TABLE . '` ON `' . $tableinfo['tablename']
-			. '`.`id` = `' . self::RELATION_TABLE . '`.`objid` WHERE `'
-			. self::RELATION_TABLE . '`.`categoryid` = ?';
-
-		try {
-			$stmt = OCP\DB::prepare($sql, $limit, $offset);
-			$result = $stmt->execute(array($catid));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-				return false;
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-
-		if(!is_null($result)) {
-			while( $row = $result->fetchRow()) {
-				$items[] = $row;
-			}
-		}
-		//OCP\Util::writeLog('core', __METHOD__.', count: ' . count($items), OCP\Util::DEBUG);
-		//OCP\Util::writeLog('core', __METHOD__.', sql: ' . $sql, OCP\Util::DEBUG);
-
-		return $items;
-	}
-
-	/**
-	* @brief Checks whether a category is already saved.
-	* @param $name The name to check for.
-	* @returns bool
-	*/
-	public function hasCategory($name) {
-		return $this->in_arrayi($name, $this->categories);
-	}
-
-	/**
-	* @brief Add a new category.
-	* @param $name A string with a name of the category
-	* @returns int the id of the added category or false if it already exists.
-	*/
-	public function add($name) {
-		$name = trim($name);
-		OCP\Util::writeLog('core', __METHOD__.', name: ' . $name, OCP\Util::DEBUG);
-		if($this->hasCategory($name)) {
-			OCP\Util::writeLog('core', __METHOD__.', name: ' . $name. ' exists already', OCP\Util::DEBUG);
-			return false;
-		}
-		try {
-			OCP\DB::insertIfNotExist(self::CATEGORY_TABLE,
-				array(
-					'uid' => $this->user,
-					'type' => $this->type,
-					'category' => $name,
-				));
-			} catch(Exception $e) {
-				OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-					OCP\Util::ERROR);
-				return false;
-			}
-		$id = OCP\DB::insertid(self::CATEGORY_TABLE);
-		OCP\Util::writeLog('core', __METHOD__.', id: ' . $id, OCP\Util::DEBUG);
-		$this->categories[$id] = $name;
-		return $id;
-	}
-
-	/**
-	* @brief Rename category.
-	* @param string $from The name of the existing category
-	* @param string $to The new name of the category.
-	* @returns bool
-	*/
-	public function rename($from, $to) {
-		$from = trim($from);
-		$to = trim($to);
-		$id = $this->array_searchi($from, $this->categories);
-		if($id === false) {
-			OCP\Util::writeLog('core', __METHOD__.', category: ' . $from. ' does not exist', OCP\Util::DEBUG);
-			return false;
-		}
-
-		$sql = 'UPDATE `' . self::CATEGORY_TABLE . '` SET `category` = ? '
-			. 'WHERE `uid` = ? AND `type` = ? AND `id` = ?';
-		try {
-			$stmt = OCP\DB::prepare($sql);
-			$result = $stmt->execute(array($to, $this->user, $this->type, $id));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-				return false;
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-		$this->categories[$id] = $to;
-		return true;
-	}
-
-	/**
-	* @brief Add a new category.
-	* @param $names A string with a name or an array of strings containing
-	* the name(s) of the categor(y|ies) to add.
-	* @param $sync bool When true, save the categories
-	* @param $id int Optional object id to add to this|these categor(y|ies)
-	* @returns bool Returns false on error.
-	*/
-	public function addMulti($names, $sync=false, $id = null) {
-		if(!is_array($names)) {
-			$names = array($names);
-		}
-		$names = array_map('trim', $names);
-		$newones = array();
-		foreach($names as $name) {
-			if(($this->in_arrayi(
-				$name, $this->categories) == false) && $name != '') {
-				$newones[] = $name;
-			}
-			if(!is_null($id) ) {
-				// Insert $objectid, $categoryid  pairs if not exist.
-				self::$relations[] = array('objid' => $id, 'category' => $name);
-			}
-		}
-		$this->categories = array_merge($this->categories, $newones);
-		if($sync === true) {
-			$this->save();
-		}
-
-		return true;
-	}
-
-	/**
-	* @brief Extracts categories from a vobject and add the ones not already present.
-	* @param $vobject The instance of OC_VObject to load the categories from.
-	*/
-	public function loadFromVObject($id, $vobject, $sync=false) {
-		$this->addMulti($vobject->getAsArray('CATEGORIES'), $sync, $id);
-	}
-
-	/**
-	* @brief Reset saved categories and rescan supplied vobjects for categories.
-	* @param $objects An array of vobjects (as text).
-	* To get the object array, do something like:
-	*	// For Addressbook:
-	*	$categories = new OC_VCategories('contacts');
-	*	$stmt = OC_DB::prepare( 'SELECT `carddata` FROM `*PREFIX*contacts_cards`' );
-	*	$result = $stmt->execute();
-	*	$objects = array();
-	*	if(!is_null($result)) {
-	*		while( $row = $result->fetchRow()){
-	*			$objects[] = array($row['id'], $row['carddata']);
-	*		}
-	*	}
-	*	$categories->rescan($objects);
-	*/
-	public function rescan($objects, $sync=true, $reset=true) {
-
-		if($reset === true) {
-			$result = null;
-			// Find all objectid/categoryid pairs.
-			try {
-				$stmt = OCP\DB::prepare('SELECT `id` FROM `' . self::CATEGORY_TABLE . '` '
-					. 'WHERE `uid` = ? AND `type` = ?');
-				$result = $stmt->execute(array($this->user, $this->type));
-				if (OC_DB::isError($result)) {
-					OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-					return false;
-				}
-			} catch(Exception $e) {
-				OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-					OCP\Util::ERROR);
-			}
-
-			// And delete them.
-			if(!is_null($result)) {
-				$stmt = OCP\DB::prepare('DELETE FROM `' . self::RELATION_TABLE . '` '
-					. 'WHERE `categoryid` = ? AND `type`= ?');
-				while( $row = $result->fetchRow()) {
-					$stmt->execute(array($row['id'], $this->type));
-				}
-			}
-			try {
-				$stmt = OCP\DB::prepare('DELETE FROM `' . self::CATEGORY_TABLE . '` '
-					. 'WHERE `uid` = ? AND `type` = ?');
-				$result = $stmt->execute(array($this->user, $this->type));
-				if (OC_DB::isError($result)) {
-					OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-					return;
-				}
-			} catch(Exception $e) {
-				OCP\Util::writeLog('core', __METHOD__ . ', exception: '
-					. $e->getMessage(), OCP\Util::ERROR);
-				return;
-			}
-			$this->categories = array();
-		}
-		// Parse all the VObjects
-		foreach($objects as $object) {
-			$vobject = OC_VObject::parse($object[1]);
-			if(!is_null($vobject)) {
-				// Load the categories
-				$this->loadFromVObject($object[0], $vobject, $sync);
-			} else {
-				OC_Log::write('core', __METHOD__ . ', unable to parse. ID: ' . ', '
-					. substr($object, 0, 100) . '(...)', OC_Log::DEBUG);
-			}
-		}
-		$this->save();
-	}
-
-	/**
-	 * @brief Save the list with categories
-	 */
-	private function save() {
-		if(is_array($this->categories)) {
-			foreach($this->categories as $category) {
-				try {
-					OCP\DB::insertIfNotExist(self::CATEGORY_TABLE,
-						array(
-							'uid' => $this->user,
-							'type' => $this->type,
-							'category' => $category,
-						));
-				} catch(Exception $e) {
-					OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-						OCP\Util::ERROR);
-				}
-			}
-			// reload categories to get the proper ids.
-			$this->loadCategories();
-			// Loop through temporarily cached objectid/categoryname pairs
-			// and save relations.
-			$categories = $this->categories;
-			// For some reason this is needed or array_search(i) will return 0..?
-			ksort($categories);
-			foreach(self::$relations as $relation) {
-				$catid = $this->array_searchi($relation['category'], $categories);
-				OC_Log::write('core', __METHOD__ . 'catid, ' . $relation['category'] . ' ' . $catid, OC_Log::DEBUG);
-				if($catid) {
-					try {
-						OCP\DB::insertIfNotExist(self::RELATION_TABLE,
-							array(
-								'objid' => $relation['objid'],
-								'categoryid' => $catid,
-								'type' => $this->type,
-								));
-					} catch(Exception $e) {
-						OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-							OCP\Util::ERROR);
-					}
-				}
-			}
-			self::$relations = array(); // reset
-		} else {
-			OC_Log::write('core', __METHOD__.', $this->categories is not an array! '
-				. print_r($this->categories, true), OC_Log::ERROR);
-		}
-	}
-
-	/**
-	* @brief Delete categories and category/object relations for a user.
-	* For hooking up on post_deleteUser
-	* @param string $uid The user id for which entries should be purged.
-	*/
-	public static function post_deleteUser($arguments) {
-		// Find all objectid/categoryid pairs.
-		$result = null;
-		try {
-			$stmt = OCP\DB::prepare('SELECT `id` FROM `' . self::CATEGORY_TABLE . '` '
-				. 'WHERE `uid` = ?');
-			$result = $stmt->execute(array($arguments['uid']));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-		}
-
-		if(!is_null($result)) {
-			try {
-				$stmt = OCP\DB::prepare('DELETE FROM `' . self::RELATION_TABLE . '` '
-					. 'WHERE `categoryid` = ?');
-				while( $row = $result->fetchRow()) {
-					try {
-						$stmt->execute(array($row['id']));
-					} catch(Exception $e) {
-						OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-							OCP\Util::ERROR);
-					}
-				}
-			} catch(Exception $e) {
-				OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-					OCP\Util::ERROR);
-			}
-		}
-		try {
-			$stmt = OCP\DB::prepare('DELETE FROM `' . self::CATEGORY_TABLE . '` '
-				. 'WHERE `uid` = ?');
-			$result = $stmt->execute(array($arguments['uid']));
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__ . ', exception: '
-				. $e->getMessage(), OCP\Util::ERROR);
-		}
-	}
-
-	/**
-	* @brief Delete category/object relations from the db
-	* @param array $ids The ids of the objects
-	* @param string $type The type of object (event/contact/task/journal).
-	* 	Defaults to the type set in the instance
-	* @returns boolean Returns false on error.
-	*/
-	public function purgeObjects(array $ids, $type = null) {
-		$type = is_null($type) ? $this->type : $type;
-		if(count($ids) === 0) {
-			// job done ;)
-			return true;
-		}
-		$updates = $ids;
-		try {
-			$query = 'DELETE FROM `' . self::RELATION_TABLE . '` ';
-			$query .= 'WHERE `objid` IN (' . str_repeat('?,', count($ids)-1) . '?) ';
-			$query .= 'AND `type`= ?';
-			$updates[] = $type;
-			$stmt = OCP\DB::prepare($query);
-			$result = $stmt->execute($updates);
-			if (OC_DB::isError($result)) {
-				OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-				return false;
-			}
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: ' . $e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-		return true;
-	}
-
-	/**
-	* Get favorites for an object type
-	*
-	* @param string $type The type of object (event/contact/task/journal).
-	* 	Defaults to the type set in the instance
-	* @returns array An array of object ids.
-	*/
-	public function getFavorites($type = null) {
-		$type = is_null($type) ? $this->type : $type;
-
-		try {
-			return $this->idsForCategory(self::CATEGORY_FAVORITE);
-		} catch(Exception $e) {
-			// No favorites
-			return array();
-		}
-	}
-
-	/**
-	* Add an object to favorites
-	*
-	* @param int $objid The id of the object
-	* @param string $type The type of object (event/contact/task/journal).
-	* 	Defaults to the type set in the instance
-	* @returns boolean
-	*/
-	public function addToFavorites($objid, $type = null) {
-		$type = is_null($type) ? $this->type : $type;
-		if(!$this->hasCategory(self::CATEGORY_FAVORITE)) {
-			$this->add(self::CATEGORY_FAVORITE, true);
-		}
-		return $this->addToCategory($objid, self::CATEGORY_FAVORITE, $type);
-	}
-
-	/**
-	* Remove an object from favorites
-	*
-	* @param int $objid The id of the object
-	* @param string $type The type of object (event/contact/task/journal).
-	* 	Defaults to the type set in the instance
-	* @returns boolean
-	*/
-	public function removeFromFavorites($objid, $type = null) {
-		$type = is_null($type) ? $this->type : $type;
-		return $this->removeFromCategory($objid, self::CATEGORY_FAVORITE, $type);
-	}
-
-	/**
-	* @brief Creates a category/object relation.
-	* @param int $objid The id of the object
-	* @param int|string $category The id or name of the category
-	* @param string $type The type of object (event/contact/task/journal).
-	* 	Defaults to the type set in the instance
-	* @returns boolean Returns false on database error.
-	*/
-	public function addToCategory($objid, $category, $type = null) {
-		$type = is_null($type) ? $this->type : $type;
-		if(is_string($category) && !is_numeric($category)) {
-			$category = trim($category);
-			if(!$this->hasCategory($category)) {
-				$this->add($category, true);
-			}
-			$categoryid =  $this->array_searchi($category, $this->categories);
-		} else {
-			$categoryid = $category;
-		}
-		try {
-			OCP\DB::insertIfNotExist(self::RELATION_TABLE,
-				array(
-					'objid' => $objid,
-					'categoryid' => $categoryid,
-					'type' => $type,
-				));
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-		return true;
-	}
-
-	/**
-	* @brief Delete single category/object relation from the db
-	* @param int $objid The id of the object
-	* @param int|string $category The id or name of the category
-	* @param string $type The type of object (event/contact/task/journal).
-	* 	Defaults to the type set in the instance
-	* @returns boolean
-	*/
-	public function removeFromCategory($objid, $category, $type = null) {
-		$type = is_null($type) ? $this->type : $type;
-		if(is_string($category) && !is_numeric($category)) {
-			$category = trim($category);
-			$categoryid =  $this->array_searchi($category, $this->categories);
-		} else {
-			$categoryid = $category;
-		}
-
-		try {
-			$sql = 'DELETE FROM `' . self::RELATION_TABLE . '` '
-					. 'WHERE `objid` = ? AND `categoryid` = ? AND `type` = ?';
-			OCP\Util::writeLog('core', __METHOD__.', sql: ' . $objid . ' ' . $categoryid . ' ' . $type,
-				OCP\Util::DEBUG);
-			$stmt = OCP\DB::prepare($sql);
-			$stmt->execute(array($objid, $categoryid, $type));
-		} catch(Exception $e) {
-			OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-				OCP\Util::ERROR);
-			return false;
-		}
-		return true;
-	}
-
-	/**
-	* @brief Delete categories from the db and from all the vobject supplied
-	* @param $names An array of categories to delete
-	* @param $objects An array of arrays with [id,vobject] (as text) pairs suitable for updating the apps object table.
-	*/
-	public function delete($names, array &$objects=null) {
-		if(!is_array($names)) {
-			$names = array($names);
-		}
-
-		$names = array_map('trim', $names);
-
-		OC_Log::write('core', __METHOD__ . ', before: '
-			. print_r($this->categories, true), OC_Log::DEBUG);
-		foreach($names as $name) {
-			$id = null;
-			OC_Log::write('core', __METHOD__.', '.$name, OC_Log::DEBUG);
-			if($this->hasCategory($name)) {
-				$id = $this->array_searchi($name, $this->categories);
-				unset($this->categories[$id]);
-			}
-			try {
-				$stmt = OCP\DB::prepare('DELETE FROM `' . self::CATEGORY_TABLE . '` WHERE '
-					. '`uid` = ? AND `type` = ? AND `category` = ?');
-				$result = $stmt->execute(array($this->user, $this->type, $name));
-				if (OC_DB::isError($result)) {
-					OC_Log::write('core', __METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result), OC_Log::ERROR);
-				}
-			} catch(Exception $e) {
-				OCP\Util::writeLog('core', __METHOD__ . ', exception: '
-					. $e->getMessage(), OCP\Util::ERROR);
-			}
-			if(!is_null($id) && $id !== false) {
-				try {
-					$sql = 'DELETE FROM `' . self::RELATION_TABLE . '` '
-							. 'WHERE `categoryid` = ?';
-					$stmt = OCP\DB::prepare($sql);
-					$result = $stmt->execute(array($id));
-					if (OC_DB::isError($result)) {
-						OC_Log::write('core',
-							__METHOD__. 'DB error: ' . OC_DB::getErrorMessage($result),
-							OC_Log::ERROR);
-					}
-				} catch(Exception $e) {
-					OCP\Util::writeLog('core', __METHOD__.', exception: '.$e->getMessage(),
-						OCP\Util::ERROR);
-					return false;
-				}
-			}
-		}
-		OC_Log::write('core', __METHOD__.', after: '
-			. print_r($this->categories, true), OC_Log::DEBUG);
-		if(!is_null($objects)) {
-			foreach($objects as $key=>&$value) {
-				$vobject = OC_VObject::parse($value[1]);
-				if(!is_null($vobject)) {
-					$object = null;
-					$componentname = '';
-					if (isset($vobject->VEVENT)) {
-						$object = $vobject->VEVENT;
-						$componentname = 'VEVENT';
-					} else
-					if (isset($vobject->VTODO)) {
-						$object = $vobject->VTODO;
-						$componentname = 'VTODO';
-					} else
-					if (isset($vobject->VJOURNAL)) {
-						$object = $vobject->VJOURNAL;
-						$componentname = 'VJOURNAL';
-					} else {
-						$object = $vobject;
-					}
-					$categories = $object->getAsArray('CATEGORIES');
-					foreach($names as $name) {
-						$idx = $this->array_searchi($name, $categories);
-						if($idx !== false) {
-							OC_Log::write('core', __METHOD__
-								.', unsetting: '
-								. $categories[$this->array_searchi($name, $categories)],
-								OC_Log::DEBUG);
-							unset($categories[$this->array_searchi($name, $categories)]);
-						}
-					}
-
-					$object->setString('CATEGORIES', implode(',', $categories));
-					if($vobject !== $object) {
-						$vobject[$componentname] = $object;
-					}
-					$value[1] = $vobject->serialize();
-					$objects[$key] = $value;
-				} else {
-					OC_Log::write('core', __METHOD__
-						.', unable to parse. ID: ' . $value[0] . ', '
-						. substr($value[1], 0, 50) . '(...)', OC_Log::DEBUG);
-				}
-			}
-		}
-	}
-
-	// case-insensitive in_array
-	private function in_arrayi($needle, $haystack) {
-		if(!is_array($haystack)) {
-			return false;
-		}
-		return in_array(strtolower($needle), array_map('strtolower', $haystack));
-	}
-
-	// case-insensitive array_search
-	private function array_searchi($needle, $haystack) {
-		if(!is_array($haystack)) {
-			return false;
-		}
-		return array_search(strtolower($needle), array_map('strtolower', $haystack));
-	}
-}