Move event and todo parsing to new API

Signed-off-by: Joas Schilling <coding@schilljs.com>

5 files changed, 368 insertions, 302 deletions

diff --git a/apps/dav/lib/AppInfo/Application.php b/apps/dav/lib/AppInfo/Application.php
index 7c32fda8f5a..669c52d1489 100644
--- a/apps/dav/lib/AppInfo/Application.php
+++ b/apps/dav/lib/AppInfo/Application.php
@@ -26,6 +26,7 @@ namespace OCA\DAV\AppInfo;
 
 use OCA\DAV\CalDAV\Activity\Backend;
 use OCA\DAV\CalDAV\Activity\Extension;
+use OCA\DAV\CalDAV\Activity\Provider\Event;
 use OCA\DAV\CalDAV\BirthdayService;
 use OCA\DAV\Capabilities;
 use OCA\DAV\CardDAV\ContactsManager;
@@ -146,11 +147,11 @@ class Application extends App {
 			/** @var Backend $backend */
 			$backend = $this->getContainer()->query(Backend::class);
 
-			$subject = Extension::SUBJECT_OBJECT_ADD;
+			$subject = Event::SUBJECT_OBJECT_ADD;
 			if ($eventName === '\OCA\DAV\CalDAV\CalDavBackend::updateCalendarObject') {
-				$subject = Extension::SUBJECT_OBJECT_UPDATE;
+				$subject = Event::SUBJECT_OBJECT_UPDATE;
 			} else if ($eventName === '\OCA\DAV\CalDAV\CalDavBackend::deleteCalendarObject') {
-				$subject = Extension::SUBJECT_OBJECT_DELETE;
+				$subject = Event::SUBJECT_OBJECT_DELETE;
 			}
 			$backend->onTouchCalendarObject(
 				$subject,
@@ -162,11 +163,6 @@ class Application extends App {
 		$dispatcher->addListener('\OCA\DAV\CalDAV\CalDavBackend::createCalendarObject', $listener);
 		$dispatcher->addListener('\OCA\DAV\CalDAV\CalDavBackend::updateCalendarObject', $listener);
 		$dispatcher->addListener('\OCA\DAV\CalDAV\CalDavBackend::deleteCalendarObject', $listener);
-
-		$aM = $this->getContainer()->getServer()->getActivityManager();
-		$aM->registerExtension(function() {
-			return $this->getContainer()->query(Extension::class);
-		});
 	}
 
 	public function getSyncService() {
diff --git a/apps/dav/lib/CalDAV/Activity/Backend.php b/apps/dav/lib/CalDAV/Activity/Backend.php
index 6a557fef7bd..953fdcea832 100644
--- a/apps/dav/lib/CalDAV/Activity/Backend.php
+++ b/apps/dav/lib/CalDAV/Activity/Backend.php
@@ -22,6 +22,8 @@
 namespace OCA\DAV\CalDAV\Activity;
 
 
+use OCA\DAV\CalDAV\Activity\Provider\Calendar;
+use OCA\DAV\CalDAV\Activity\Provider\Event;
 use OCP\Activity\IEvent;
 use OCP\Activity\IManager as IActivityManager;
 use OCP\IGroup;
@@ -63,7 +65,7 @@ class Backend {
 	 * @param array $calendarData
 	 */
 	public function onCalendarAdd(array $calendarData) {
-		$this->triggerCalendarActivity(Extension::SUBJECT_ADD, $calendarData);
+		$this->triggerCalendarActivity(Calendar::SUBJECT_ADD, $calendarData);
 	}
 
 	/**
@@ -74,7 +76,7 @@ class Backend {
 	 * @param array $properties
 	 */
 	public function onCalendarUpdate(array $calendarData, array $shares, array $properties) {
-		$this->triggerCalendarActivity(Extension::SUBJECT_UPDATE, $calendarData, $shares, $properties);
+		$this->triggerCalendarActivity(Calendar::SUBJECT_UPDATE, $calendarData, $shares, $properties);
 	}
 
 	/**
@@ -84,7 +86,7 @@ class Backend {
 	 * @param array $shares
 	 */
 	public function onCalendarDelete(array $calendarData, array $shares) {
-		$this->triggerCalendarActivity(Extension::SUBJECT_DELETE, $calendarData, $shares);
+		$this->triggerCalendarActivity(Calendar::SUBJECT_DELETE, $calendarData, $shares);
 	}
 
 	/**
@@ -112,8 +114,8 @@ class Backend {
 
 		$event = $this->activityManager->generateEvent();
 		$event->setApp('dav')
-			->setObject(Extension::CALENDAR, (int) $calendarData['id'])
-			->setType(Extension::CALENDAR)
+			->setObject('calendar', (int) $calendarData['id'])
+			->setType('calendar')
 			->setAuthor($currentUser);
 
 		$changedVisibleInformation = array_intersect([
@@ -121,7 +123,7 @@ class Backend {
 			'{http://apple.com/ns/ical/}calendar-color'
 		], array_keys($changedProperties));
 
-		if (empty($shares) || ($action === Extension::SUBJECT_UPDATE && empty($changedVisibleInformation))) {
+		if (empty($shares) || ($action === Calendar::SUBJECT_UPDATE && empty($changedVisibleInformation))) {
 			$users = [$owner];
 		} else {
 			$users = $this->getUsersForShares($shares);
@@ -162,8 +164,8 @@ class Backend {
 
 		$event = $this->activityManager->generateEvent();
 		$event->setApp('dav')
-			->setObject(Extension::CALENDAR, (int) $calendarData['id'])
-			->setType(Extension::CALENDAR)
+			->setObject('calendar', (int) $calendarData['id'])
+			->setType('calendar')
 			->setAuthor($currentUser);
 
 		foreach ($remove as $principal) {
@@ -179,8 +181,8 @@ class Backend {
 					$principal[2],
 					$event,
 					$calendarData,
-					Extension::SUBJECT_UNSHARE_USER,
-					Extension::SUBJECT_DELETE . '_self'
+					Calendar::SUBJECT_UNSHARE_USER,
+					Calendar::SUBJECT_DELETE . '_self'
 				);
 
 				if ($owner !== $principal[2]) {
@@ -190,15 +192,15 @@ class Backend {
 					];
 
 					if ($owner === $event->getAuthor()) {
-						$subject = Extension::SUBJECT_UNSHARE_USER . '_you';
+						$subject = Calendar::SUBJECT_UNSHARE_USER . '_you';
 					} else if ($principal[2] === $event->getAuthor()) {
-						$subject = Extension::SUBJECT_UNSHARE_USER . '_self';
+						$subject = Calendar::SUBJECT_UNSHARE_USER . '_self';
 					} else {
 						$event->setAffectedUser($event->getAuthor())
-							->setSubject(Extension::SUBJECT_UNSHARE_USER . '_you', $parameters);
+							->setSubject(Calendar::SUBJECT_UNSHARE_USER . '_you', $parameters);
 						$this->activityManager->publish($event);
 
-						$subject = Extension::SUBJECT_UNSHARE_USER . '_by';
+						$subject = Calendar::SUBJECT_UNSHARE_USER . '_by';
 						$parameters[] = $event->getAuthor();
 					}
 
@@ -207,7 +209,7 @@ class Backend {
 					$this->activityManager->publish($event);
 				}
 			} else if ($principal[1] === 'groups') {
-				$this->triggerActivityGroup($principal[2], $event, $calendarData, Extension::SUBJECT_UNSHARE_USER);
+				$this->triggerActivityGroup($principal[2], $event, $calendarData, Calendar::SUBJECT_UNSHARE_USER);
 
 				$parameters = [
 					$principal[2],
@@ -215,13 +217,13 @@ class Backend {
 				];
 
 				if ($owner === $event->getAuthor()) {
-					$subject = Extension::SUBJECT_UNSHARE_GROUP . '_you';
+					$subject = Calendar::SUBJECT_UNSHARE_GROUP . '_you';
 				} else {
 					$event->setAffectedUser($event->getAuthor())
-						->setSubject(Extension::SUBJECT_UNSHARE_GROUP . '_you', $parameters);
+						->setSubject(Calendar::SUBJECT_UNSHARE_GROUP . '_you', $parameters);
 					$this->activityManager->publish($event);
 
-					$subject = Extension::SUBJECT_UNSHARE_GROUP . '_by';
+					$subject = Calendar::SUBJECT_UNSHARE_GROUP . '_by';
 					$parameters[] = $event->getAuthor();
 				}
 
@@ -244,7 +246,7 @@ class Backend {
 			$principal = explode('/', $parts[1]);
 
 			if ($principal[1] === 'users') {
-				$this->triggerActivityUser($principal[2], $event, $calendarData, Extension::SUBJECT_SHARE_USER);
+				$this->triggerActivityUser($principal[2], $event, $calendarData, Calendar::SUBJECT_SHARE_USER);
 
 				if ($owner !== $principal[2]) {
 					$parameters = [
@@ -253,13 +255,13 @@ class Backend {
 					];
 
 					if ($owner === $event->getAuthor()) {
-						$subject = Extension::SUBJECT_SHARE_USER . '_you';
+						$subject = Calendar::SUBJECT_SHARE_USER . '_you';
 					} else {
 						$event->setAffectedUser($event->getAuthor())
-							->setSubject(Extension::SUBJECT_SHARE_USER . '_you', $parameters);
+							->setSubject(Calendar::SUBJECT_SHARE_USER . '_you', $parameters);
 						$this->activityManager->publish($event);
 
-						$subject = Extension::SUBJECT_SHARE_USER . '_by';
+						$subject = Calendar::SUBJECT_SHARE_USER . '_by';
 						$parameters[] = $event->getAuthor();
 					}
 
@@ -268,7 +270,7 @@ class Backend {
 					$this->activityManager->publish($event);
 				}
 			} else if ($principal[1] === 'groups') {
-				$this->triggerActivityGroup($principal[2], $event, $calendarData, Extension::SUBJECT_SHARE_USER);
+				$this->triggerActivityGroup($principal[2], $event, $calendarData, Calendar::SUBJECT_SHARE_USER);
 
 				$parameters = [
 					$principal[2],
@@ -276,13 +278,13 @@ class Backend {
 				];
 
 				if ($owner === $event->getAuthor()) {
-					$subject = Extension::SUBJECT_SHARE_GROUP . '_you';
+					$subject = Calendar::SUBJECT_SHARE_GROUP . '_you';
 				} else {
 					$event->setAffectedUser($event->getAuthor())
-						->setSubject(Extension::SUBJECT_SHARE_GROUP . '_you', $parameters);
+						->setSubject(Calendar::SUBJECT_SHARE_GROUP . '_you', $parameters);
 					$this->activityManager->publish($event);
 
-					$subject = Extension::SUBJECT_SHARE_GROUP . '_by';
+					$subject = Calendar::SUBJECT_SHARE_GROUP . '_by';
 					$parameters[] = $event->getAuthor();
 				}
 
@@ -379,16 +381,16 @@ class Backend {
 		$object = $this->getObjectNameAndType($objectData);
 		$action = $action . '_' . $object['type'];
 
-		if ($object['type'] === 'todo' && strpos($action, Extension::SUBJECT_OBJECT_UPDATE) === 0 && $object['status'] === 'COMPLETED') {
+		if ($object['type'] === 'todo' && strpos($action, Event::SUBJECT_OBJECT_UPDATE) === 0 && $object['status'] === 'COMPLETED') {
 			$action .= '_completed';
-		} else if ($object['type'] === 'todo' && strpos($action, Extension::SUBJECT_OBJECT_UPDATE) === 0 && $object['status'] === 'NEEDS-ACTION') {
+		} else if ($object['type'] === 'todo' && strpos($action, Event::SUBJECT_OBJECT_UPDATE) === 0 && $object['status'] === 'NEEDS-ACTION') {
 			$action .= '_needs_action';
 		}
 
 		$event = $this->activityManager->generateEvent();
 		$event->setApp('dav')
-			->setObject(Extension::CALENDAR, (int) $calendarData['id'])
-			->setType($object['type'] === 'event' ? Extension::CALENDAR_EVENT : Extension::CALENDAR_TODO)
+			->setObject('calendar', (int) $calendarData['id'])
+			->setType($object['type'] === 'event' ? 'calendar_event' : 'calendar_todo')
 			->setAuthor($currentUser);
 
 		$users = $this->getUsersForShares($shares);
@@ -401,7 +403,10 @@ class Backend {
 					[
 						$currentUser,
 						$calendarData['{DAV:}displayname'],
-						$object['name'],
+						[
+							'id' => $object['id'],
+							'name' => $object['name'],
+						],
 					]
 				);
 			$this->activityManager->publish($event);
@@ -428,9 +433,9 @@ class Backend {
 		}
 
 		if ($componentType === 'VEVENT') {
-			return ['name' => (string) $component->SUMMARY, 'type' => 'event'];
+			return ['id' => (string) $component->UID, 'name' => (string) $component->SUMMARY, 'type' => 'event'];
 		}
-		return ['name' => (string) $component->SUMMARY, 'type' => 'todo', 'status' => (string) $component->STATUS];
+		return ['id' => (string) $component->UID, 'name' => (string) $component->SUMMARY, 'type' => 'todo', 'status' => (string) $component->STATUS];
 	}
 
 	/**
diff --git a/apps/dav/lib/CalDAV/Activity/Extension.php b/apps/dav/lib/CalDAV/Activity/Extension.php
deleted file mode 100644
index b6d4e23b71d..00000000000
--- a/apps/dav/lib/CalDAV/Activity/Extension.php
+++ /dev/null
@@ -1,261 +0,0 @@
-<?php
-/**
- * @copyright Copyright (c) 2016 Joas Schilling <coding@schilljs.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\DAV\CalDAV\Activity;
-
-use OCP\Activity\IExtension;
-use OCP\IURLGenerator;
-use OCP\L10N\IFactory;
-
-class Extension implements IExtension {
-	const APP = 'dav';
-	/**
-	 * Filter with all sharing related activities
-	 */
-	const CALENDAR = 'calendar';
-	const CALENDAR_EVENT = 'calendar_event';
-	const CALENDAR_TODO = 'calendar_todo';
-
-	const SUBJECT_ADD = 'calendar_add';
-	const SUBJECT_UPDATE = 'calendar_update';
-	const SUBJECT_DELETE = 'calendar_delete';
-	const SUBJECT_SHARE_USER = 'calendar_user_share';
-	const SUBJECT_SHARE_GROUP = 'calendar_group_share';
-	const SUBJECT_UNSHARE_USER = 'calendar_user_unshare';
-	const SUBJECT_UNSHARE_GROUP = 'calendar_group_unshare';
-
-	const SUBJECT_OBJECT_ADD = 'object_add';
-	const SUBJECT_OBJECT_UPDATE = 'object_update';
-	const SUBJECT_OBJECT_DELETE = 'object_delete';
-
-	/** @var IFactory */
-	protected $languageFactory;
-
-	/** @var IURLGenerator */
-	protected $URLGenerator;
-
-	/**
-	 * @param IFactory $languageFactory
-	 * @param IURLGenerator $URLGenerator
-	 */
-	public function __construct(IFactory $languageFactory, IURLGenerator $URLGenerator) {
-		$this->languageFactory = $languageFactory;
-		$this->URLGenerator = $URLGenerator;
-	}
-
-	protected function getL10N($languageCode = null) {
-		return $this->languageFactory->get(self::APP, $languageCode);
-	}
-
-	/**
-	 * The extension can return an array of additional notification types.
-	 * If no additional types are to be added false is to be returned
-	 *
-	 * @param string $languageCode
-	 * @return array|false
-	 */
-	public function getNotificationTypes($languageCode) {
-		return false;
-	}
-
-	/**
-	 * For a given method additional types to be displayed in the settings can be returned.
-	 * In case no additional types are to be added false is to be returned.
-	 *
-	 * @param string $method
-	 * @return array|false
-	 */
-	public function getDefaultTypes($method) {
-		return false;
-	}
-
-	/**
-	 * A string naming the css class for the icon to be used can be returned.
-	 * If no icon is known for the given type false is to be returned.
-	 *
-	 * @param string $type
-	 * @return string|false
-	 */
-	public function getTypeIcon($type) {
-		return false;
-	}
-
-	/**
-	 * The extension can translate a given message to the requested languages.
-	 * If no translation is available false is to be returned.
-	 *
-	 * @param string $app
-	 * @param string $text
-	 * @param array $params
-	 * @param boolean $stripPath
-	 * @param boolean $highlightParams
-	 * @param string $languageCode
-	 * @return string|false
-	 */
-	public function translate($app, $text, $params, $stripPath, $highlightParams, $languageCode) {
-		if ($app !== self::APP) {
-			return false;
-		}
-
-		$l = $this->getL10N($languageCode);
-
-		switch ($text) {
-			case self::SUBJECT_OBJECT_ADD . '_event':
-				return (string) $l->t('%1$s created event %3$s in calendar %2$s', $params);
-			case self::SUBJECT_OBJECT_ADD . '_event_self':
-				return (string) $l->t('You created event %3$s in calendar %2$s', $params);
-			case self::SUBJECT_OBJECT_DELETE . '_event':
-				return (string) $l->t('%1$s deleted event %3$s from calendar %2$s', $params);
-			case self::SUBJECT_OBJECT_DELETE . '_event_self':
-				return (string) $l->t('You deleted event %3$s from calendar %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_event':
-				return (string) $l->t('%1$s updated event %3$s in calendar %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_event_self':
-				return (string) $l->t('You updated event %3$s in calendar %2$s', $params);
-
-			case self::SUBJECT_OBJECT_ADD . '_todo':
-				return (string) $l->t('%1$s created todo %3$s in list %2$s', $params);
-			case self::SUBJECT_OBJECT_ADD . '_todo_self':
-				return (string) $l->t('You created todo %3$s in list %2$s', $params);
-			case self::SUBJECT_OBJECT_DELETE . '_todo':
-				return (string) $l->t('%1$s deleted todo %3$s from list %2$s', $params);
-			case self::SUBJECT_OBJECT_DELETE . '_todo_self':
-				return (string) $l->t('You deleted todo %3$s from list %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_todo':
-				return (string) $l->t('%1$s updated todo %3$s in list %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_todo_self':
-				return (string) $l->t('You updated todo %3$s in list %2$s', $params);
-
-			case self::SUBJECT_OBJECT_UPDATE . '_todo_completed':
-				return (string) $l->t('%1$s solved todo %3$s in list %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_todo_completed_self':
-				return (string) $l->t('You solved todo %3$s in list %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action':
-				return (string) $l->t('%1$s reopened todo %3$s in list %2$s', $params);
-			case self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action_self':
-				return (string) $l->t('You reopened todo %3$s in list %2$s', $params);
-
-		}
-
-		return false;
-	}
-
-	/**
-	 * The extension can define the type of parameters for translation
-	 *
-	 * Currently known types are:
-	 * * file		=> will strip away the path of the file and add a tooltip with it
-	 * * username	=> will add the avatar of the user
-	 *
-	 * @param string $app
-	 * @param string $text
-	 * @return array|false
-	 */
-	public function getSpecialParameterList($app, $text) {
-		if ($app === self::APP) {
-			switch ($text) {
-				case self::SUBJECT_OBJECT_ADD . '_event':
-				case self::SUBJECT_OBJECT_ADD . '_event_self':
-				case self::SUBJECT_OBJECT_DELETE . '_event':
-				case self::SUBJECT_OBJECT_DELETE . '_event_self':
-				case self::SUBJECT_OBJECT_UPDATE . '_event':
-				case self::SUBJECT_OBJECT_UPDATE . '_event_self':
-
-				case self::SUBJECT_OBJECT_ADD . '_todo':
-				case self::SUBJECT_OBJECT_ADD . '_todo_self':
-				case self::SUBJECT_OBJECT_DELETE . '_todo':
-				case self::SUBJECT_OBJECT_DELETE . '_todo_self':
-				case self::SUBJECT_OBJECT_UPDATE . '_todo':
-				case self::SUBJECT_OBJECT_UPDATE . '_todo_self':
-
-				case self::SUBJECT_OBJECT_UPDATE . '_todo_completed':
-				case self::SUBJECT_OBJECT_UPDATE . '_todo_completed_self':
-				case self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action':
-				case self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action_self':
-					return [
-						0 => 'username',
-						//1 => 'calendar',
-						//2 => 'object',
-					];
-			}
-		}
-
-		return false;
-	}
-
-	/**
-	 * The extension can define the parameter grouping by returning the index as integer.
-	 * In case no grouping is required false is to be returned.
-	 *
-	 * @param array $activity
-	 * @return integer|false
-	 */
-	public function getGroupParameter($activity) {
-		return false;
-	}
-
-	/**
-	 * The extension can define additional navigation entries. The array returned has to contain two keys 'top'
-	 * and 'apps' which hold arrays with the relevant entries.
-	 * If no further entries are to be added false is no be returned.
-	 *
-	 * @return array|false
-	 */
-	public function getNavigation() {
-		return false;
-	}
-
-	/**
-	 * The extension can check if a custom filter (given by a query string like filter=abc) is valid or not.
-	 *
-	 * @param string $filterValue
-	 * @return boolean
-	 */
-	public function isFilterValid($filterValue) {
-		return false;
-	}
-
-	/**
-	 * The extension can filter the types based on the filter if required.
-	 * In case no filter is to be applied false is to be returned unchanged.
-	 *
-	 * @param array $types
-	 * @param string $filter
-	 * @return array|false
-	 */
-	public function filterNotificationTypes($types, $filter) {
-		return false;
-	}
-
-	/**
-	 * For a given filter the extension can specify the sql query conditions including parameters for that query.
-	 * In case the extension does not know the filter false is to be returned.
-	 * The query condition and the parameters are to be returned as array with two elements.
-	 * E.g. return array('`app` = ? and `message` like ?', array('mail', 'ownCloud%'));
-	 *
-	 * @param string $filter
-	 * @return array|false
-	 */
-	public function getQueryForFilter($filter) {
-		return false;
-	}
-
-}
diff --git a/apps/dav/lib/CalDAV/Activity/Provider/Event.php b/apps/dav/lib/CalDAV/Activity/Provider/Event.php
new file mode 100644
index 00000000000..1bad07916b4
--- /dev/null
+++ b/apps/dav/lib/CalDAV/Activity/Provider/Event.php
@@ -0,0 +1,212 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Joas Schilling <coding@schilljs.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\DAV\CalDAV\Activity\Provider;
+
+use OCP\Activity\IEvent;
+use OCP\Activity\IEventMerger;
+use OCP\Activity\IManager;
+use OCP\Activity\IProvider;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\IUserManager;
+
+class Event implements IProvider {
+
+	const SUBJECT_OBJECT_ADD = 'object_add';
+	const SUBJECT_OBJECT_UPDATE = 'object_update';
+	const SUBJECT_OBJECT_DELETE = 'object_delete';
+
+	/** @var IL10N */
+	protected $l;
+
+	/** @var IURLGenerator */
+	protected $url;
+
+	/** @var IManager */
+	protected $activityManager;
+
+	/** @var IUserManager */
+	protected $userManager;
+
+	/** @var IEventMerger */
+	protected $eventMerger;
+
+	/** @var string[] cached displayNames - key is the UID and value the displayname */
+	protected $displayNames = [];
+
+	/**
+	 * @param IL10N $l
+	 * @param IURLGenerator $url
+	 * @param IManager $activityManager
+	 * @param IUserManager $userManager
+	 * @param IEventMerger $eventMerger
+	 */
+	public function __construct(IL10N $l, IURLGenerator $url, IManager $activityManager, IUserManager $userManager, IEventMerger $eventMerger) {
+		$this->l = $l;
+		$this->url = $url;
+		$this->activityManager = $activityManager;
+		$this->userManager = $userManager;
+		$this->eventMerger = $eventMerger;
+	}
+
+	/**
+	 * @param IEvent $event
+	 * @param IEvent|null $previousEvent
+	 * @return IEvent
+	 * @throws \InvalidArgumentException
+	 * @since 11.0.0
+	 */
+	public function parse(IEvent $event, IEvent $previousEvent = null) {
+		if ($event->getApp() !== 'dav' || $event->getType() !== 'calendar_event') {
+			throw new \InvalidArgumentException();
+		}
+
+		$event->setIcon($this->url->getAbsoluteURL($this->url->imagePath('core', 'places/calendar-dark.svg')));
+
+		if ($event->getSubject() === self::SUBJECT_OBJECT_ADD . '_event') {
+			$subject = $this->l->t('{actor} created event {event} in calendar {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_ADD . '_event_self') {
+			$subject = $this->l->t('You created event {event} in calendar {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_DELETE . '_event') {
+			$subject = $this->l->t('{actor} deleted event {event} from calendar {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_DELETE . '_event_self') {
+			$subject = $this->l->t('You deleted event {event} from calendar {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_event') {
+			$subject = $this->l->t('{actor} updated event {event} in calendar {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_event_self') {
+			$subject = $this->l->t('You updated event {event} in calendar {calendar}');
+		} else {
+			throw new \InvalidArgumentException();
+		}
+
+		$parsedParameters = $this->getParameters($event);
+		$this->setSubjects($event, $subject, $parsedParameters);
+
+		$event = $this->eventMerger->mergeEvents('event', $event, $previousEvent);
+
+		return $event;
+	}
+
+	/**
+	 * @param IEvent $event
+	 * @param string $subject
+	 * @param array $parameters
+	 */
+	protected function setSubjects(IEvent $event, $subject, array $parameters) {
+		$placeholders = $replacements = [];
+		foreach ($parameters as $placeholder => $parameter) {
+			$placeholders[] = '{' . $placeholder . '}';
+			$replacements[] = $parameter['name'];
+		}
+
+		$event->setParsedSubject(str_replace($placeholders, $replacements, $subject))
+			->setRichSubject($subject, $parameters);
+	}
+
+	/**
+	 * @param IEvent $event
+	 * @return array
+	 */
+	protected function getParameters(IEvent $event) {
+		$subject = $event->getSubject();
+		$parameters = $event->getSubjectParameters();
+
+		switch ($subject) {
+			case self::SUBJECT_OBJECT_ADD . '_event':
+			case self::SUBJECT_OBJECT_DELETE . '_event':
+			case self::SUBJECT_OBJECT_UPDATE . '_event':
+				return [
+					'actor' => $this->generateUserParameter($parameters[0]),
+					'calendar' => $this->generateCalendarParameter($event->getObjectId(), $parameters[1]),
+					'event' => $this->generateObjectParameter($parameters[2]),
+				];
+			case self::SUBJECT_OBJECT_ADD . '_event_self':
+			case self::SUBJECT_OBJECT_DELETE . '_event_self':
+			case self::SUBJECT_OBJECT_UPDATE . '_event_self':
+				return [
+					'calendar' => $this->generateCalendarParameter($event->getObjectId(), $parameters[1]),
+					'event' => $this->generateObjectParameter($parameters[2]),
+				];
+		}
+
+		throw new \InvalidArgumentException();
+	}
+
+	/**
+	 * @param array $eventData
+	 * @return array
+	 */
+	protected function generateObjectParameter($eventData) {
+		if (!is_array($eventData)) {
+			throw new \InvalidArgumentException();
+		};
+
+		return [
+			'type' => 'calendar-event',
+			'id' => $eventData['id'],
+			'name' => $eventData['name'],
+		];
+	}
+
+	/**
+	 * @param int $id
+	 * @param string $name
+	 * @return array
+	 */
+	protected function generateCalendarParameter($id, $name) {
+		return [
+			'type' => 'calendar',
+			'id' => $id,
+			'name' => $name,
+		];
+	}
+
+	/**
+	 * @param string $uid
+	 * @return array
+	 */
+	protected function generateUserParameter($uid) {
+		if (!isset($this->displayNames[$uid])) {
+			$this->displayNames[$uid] = $this->getDisplayName($uid);
+		}
+
+		return [
+			'type' => 'user',
+			'id' => $uid,
+			'name' => $this->displayNames[$uid],
+		];
+	}
+
+	/**
+	 * @param string $uid
+	 * @return string
+	 */
+	protected function getDisplayName($uid) {
+		$user = $this->userManager->get($uid);
+		if ($user instanceof IUser) {
+			return $user->getDisplayName();
+		} else {
+			return $uid;
+		}
+	}
+}
diff --git a/apps/dav/lib/CalDAV/Activity/Provider/Todo.php b/apps/dav/lib/CalDAV/Activity/Provider/Todo.php
new file mode 100644
index 00000000000..12c341160c0
--- /dev/null
+++ b/apps/dav/lib/CalDAV/Activity/Provider/Todo.php
@@ -0,0 +1,114 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016 Joas Schilling <coding@schilljs.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\DAV\CalDAV\Activity\Provider;
+
+use OCP\Activity\IEvent;
+use OCP\Activity\IEventMerger;
+use OCP\Activity\IManager;
+use OCP\Activity\IProvider;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\IUserManager;
+
+class Todo extends Event {
+
+	/**
+	 * @param IEvent $event
+	 * @param IEvent|null $previousEvent
+	 * @return IEvent
+	 * @throws \InvalidArgumentException
+	 * @since 11.0.0
+	 */
+	public function parse(IEvent $event, IEvent $previousEvent = null) {
+		if ($event->getApp() !== 'dav' || $event->getType() !== 'calendar_todo') {
+			throw new \InvalidArgumentException();
+		}
+
+		$event->setIcon($this->url->getAbsoluteURL($this->url->imagePath('core', 'actions/checkmark.svg')));
+
+		if ($event->getSubject() === self::SUBJECT_OBJECT_ADD . '_todo') {
+			$subject = $this->l->t('{actor} created todo {todo} in list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_ADD . '_todo_self') {
+			$subject = $this->l->t('You created todo {todo} in list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_DELETE . '_todo') {
+			$subject = $this->l->t('{actor} deleted todo {todo} from list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_DELETE . '_todo_self') {
+			$subject = $this->l->t('You deleted todo {todo} from list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_todo') {
+			$subject = $this->l->t('{actor} updated todo {todo} in list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_todo_self') {
+			$subject = $this->l->t('You updated todo {todo} in list {calendar}');
+
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_todo_completed') {
+			$subject = $this->l->t('{actor} solved todo {todo} in list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_todo_completed_self') {
+			$subject = $this->l->t('You solved todo {todo} in list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action') {
+			$subject = $this->l->t('{actor} reopened todo {todo} in list {calendar}');
+		} else if ($event->getSubject() === self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action_self') {
+			$subject = $this->l->t('You reopened todo {todo} in list {calendar}');
+		} else {
+			throw new \InvalidArgumentException();
+		}
+
+		$parsedParameters = $this->getParameters($event);
+		$this->setSubjects($event, $subject, $parsedParameters);
+
+		$event = $this->eventMerger->mergeEvents('todo', $event, $previousEvent);
+
+		return $event;
+	}
+
+	/**
+	 * @param IEvent $event
+	 * @return array
+	 */
+	protected function getParameters(IEvent $event) {
+		$subject = $event->getSubject();
+		$parameters = $event->getSubjectParameters();
+
+		switch ($subject) {
+			case self::SUBJECT_OBJECT_ADD . '_todo':
+			case self::SUBJECT_OBJECT_DELETE . '_todo':
+			case self::SUBJECT_OBJECT_UPDATE . '_todo':
+			case self::SUBJECT_OBJECT_UPDATE . '_todo_completed':
+			case self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action':
+				return [
+					'actor' => $this->generateUserParameter($parameters[0]),
+					'calendar' => $this->generateCalendarParameter($event->getObjectId(), $parameters[1]),
+					'todo' => $this->generateObjectParameter($parameters[2]),
+				];
+			case self::SUBJECT_OBJECT_ADD . '_todo_self':
+			case self::SUBJECT_OBJECT_DELETE . '_todo_self':
+			case self::SUBJECT_OBJECT_UPDATE . '_todo_self':
+			case self::SUBJECT_OBJECT_UPDATE . '_todo_completed_self':
+			case self::SUBJECT_OBJECT_UPDATE . '_todo_needs_action_self':
+				return [
+					'calendar' => $this->generateCalendarParameter($event->getObjectId(), $parameters[1]),
+					'todo' => $this->generateObjectParameter($parameters[2]),
+				];
+		}
+
+		throw new \InvalidArgumentException();
+	}
+}