Merge pull request #2179 from nextcloud/update-systemtags-to-new-activity-api

Update systemtags activity to new API

6 files changed, 425 insertions, 363 deletions

diff --git a/apps/systemtags/appinfo/app.php b/apps/systemtags/appinfo/app.php
index e3be0d7556e..039df2ac9f7 100644
--- a/apps/systemtags/appinfo/app.php
+++ b/apps/systemtags/appinfo/app.php
@@ -46,14 +46,6 @@ $eventDispatcher->addListener(
 	}
 );
 
-$activityManager = \OC::$server->getActivityManager();
-$activityManager->registerExtension(function() {
-	$application = new \OCP\AppFramework\App('systemtags');
-	/** @var \OCA\SystemTags\Activity\Extension $extension */
-	$extension = $application->getContainer()->query('OCA\SystemTags\Activity\Extension');
-	return $extension;
-});
-
 $managerListener = function(ManagerEvent $event) use ($activityManager) {
 	$application = new \OCP\AppFramework\App('systemtags');
 	/** @var \OCA\SystemTags\Activity\Listener $listener */
diff --git a/apps/systemtags/appinfo/info.xml b/apps/systemtags/appinfo/info.xml
index 3ed01d3d8c0..1d5f33207a4 100644
--- a/apps/systemtags/appinfo/info.xml
+++ b/apps/systemtags/appinfo/info.xml
@@ -18,4 +18,14 @@
 	<settings>
 		<admin>OCA\SystemTags\Settings\Admin</admin>
 	</settings>
+
+	<activity>
+		<settings>
+			<setting>OCA\SystemTags\Activity\Setting</setting>
+		</settings>
+
+		<providers>
+			<provider>OCA\SystemTags\Activity\Provider</provider>
+		</providers>
+	</activity>
 </info>
diff --git a/apps/systemtags/lib/Activity/Extension.php b/apps/systemtags/lib/Activity/Extension.php
deleted file mode 100644
index 8937d916209..00000000000
--- a/apps/systemtags/lib/Activity/Extension.php
+++ /dev/null
@@ -1,337 +0,0 @@
-<?php
-/**
- * @copyright Copyright (c) 2016, ownCloud, Inc.
- *
- * @author Joas Schilling <coding@schilljs.com>
- * @author Vincent Petry <pvince81@owncloud.com>
- *
- * @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\SystemTags\Activity;
-
-use OCP\Activity\IExtension;
-use OCP\Activity\IManager;
-use OCP\IL10N;
-use OCP\L10N\IFactory;
-
-/**
- * Class Extension
- *
- * @package OCA\SystemTags\Activity
- */
-class Extension implements IExtension {
-	const APP_NAME = 'systemtags';
-
-	const CREATE_TAG = 'create_tag';
-	const UPDATE_TAG = 'update_tag';
-	const DELETE_TAG = 'delete_tag';
-
-	const ASSIGN_TAG = 'assign_tag';
-	const UNASSIGN_TAG = 'unassign_tag';
-
-	/** @var IFactory */
-	protected $languageFactory;
-
-	/** @var IManager */
-	protected $activityManager;
-
-	/**
-	 * @param IFactory $languageFactory
-	 * @param IManager $activityManager
-	 */
-	public function __construct(IFactory $languageFactory, IManager $activityManager) {
-		$this->languageFactory = $languageFactory;
-		$this->activityManager = $activityManager;
-	}
-
-	protected function getL10N($languageCode = null) {
-		return $this->languageFactory->get(self::APP_NAME, $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) {
-		$l = $this->getL10N($languageCode);
-
-		return array(
-			self::APP_NAME => (string) $l->t('<strong>System tags</strong> for a file have been modified'),
-		);
-	}
-
-	/**
-	 * 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 $method === self::METHOD_STREAM ? [self::APP_NAME] : 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) {
-		switch ($type) {
-			case self::APP_NAME:
-				return 'icon-tag';
-		}
-
-		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_NAME) {
-			return false;
-		}
-
-		$l = $this->getL10N($languageCode);
-
-		if ($this->activityManager->isFormattingFilteredObject()) {
-			$translation = $this->translateShort($text, $l, $params);
-			if ($translation !== false) {
-				return $translation;
-			}
-		}
-
-		return $this->translateLong($text, $l, $params);
-	}
-
-	/**
-	 * @param string $text
-	 * @param IL10N $l
-	 * @param array $params
-	 * @return bool|string
-	 */
-	protected function translateShort($text, IL10N $l, array $params) {
-
-		switch ($text) {
-			case self::ASSIGN_TAG:
-				$params[2] = $this->convertParameterToTag($params[2], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You added system tag %3$s', $params);
-				}
-				return (string) $l->t('%1$s added system tag %3$s', $params);
-			case self::UNASSIGN_TAG:
-				$params[2] = $this->convertParameterToTag($params[2], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You removed system tag %3$s', $params);
-				}
-				return (string) $l->t('%1$s removed system tag %3$s', $params);
-		}
-
-		return false;
-	}
-
-	/**
-	 * @param string $text
-	 * @param IL10N $l
-	 * @param array $params
-	 * @return bool|string
-	 */
-	protected function translateLong($text, IL10N $l, array $params) {
-
-		switch ($text) {
-			case self::CREATE_TAG:
-				$params[1] = $this->convertParameterToTag($params[1], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You created system tag %2$s', $params);
-				}
-				return (string) $l->t('%1$s created system tag %2$s', $params);
-			case self::DELETE_TAG:
-				$params[1] = $this->convertParameterToTag($params[1], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You deleted system tag %2$s', $params);
-				}
-				return (string) $l->t('%1$s deleted system tag %2$s', $params);
-			case self::UPDATE_TAG:
-				$params[1] = $this->convertParameterToTag($params[1], $l);
-				$params[2] = $this->convertParameterToTag($params[2], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You updated system tag %3$s to %2$s', $params);
-				}
-				return (string) $l->t('%1$s updated system tag %3$s to %2$s', $params);
-			case self::ASSIGN_TAG:
-				$params[2] = $this->convertParameterToTag($params[2], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You added system tag %3$s to %2$s', $params);
-				}
-				return (string) $l->t('%1$s added system tag %3$s to %2$s', $params);
-			case self::UNASSIGN_TAG:
-				$params[2] = $this->convertParameterToTag($params[2], $l);
-				if ($this->actorIsCurrentUser($params[0])) {
-					return (string) $l->t('You removed system tag %3$s from %2$s', $params);
-				}
-				return (string) $l->t('%1$s removed system tag %3$s from %2$s', $params);
-		}
-
-		return false;
-	}
-
-	/**
-	 * Check if the author is the current user
-	 *
-	 * @param string $user Parameter e.g. `<user display-name="admin">admin</user>`
-	 * @return bool
-	 */
-	protected function actorIsCurrentUser($user) {
-		try {
-			return strip_tags($user) === $this->activityManager->getCurrentUserId();
-		} catch (\UnexpectedValueException $e) {
-			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_NAME) {
-			switch ($text) {
-				case self::CREATE_TAG:
-				case self::DELETE_TAG:
-					return array(
-						0 => 'username',
-						//1 => 'systemtag description',
-					);
-				case self::UPDATE_TAG:
-					return array(
-						0 => 'username',
-						//1 => 'systemtag description',
-						//2 => 'systemtag description',
-					);
-
-				case self::ASSIGN_TAG:
-				case self::UNASSIGN_TAG:
-					return array(
-						0 => 'username',
-						1 => 'file',
-						//2 => 'systemtag description',
-					);
-			}
-		}
-
-		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;
-	}
-
-	/**
-	 * @param string $parameter
-	 * @param IL10N $l
-	 * @return string
-	 */
-	protected function convertParameterToTag($parameter, IL10N $l) {
-		if (preg_match('/^\<parameter\>\{\{\{(.*)\|\|\|(.*)\}\}\}\<\/parameter\>$/', $parameter, $matches)) {
-			switch ($matches[2]) {
-				case 'assignable':
-					return '<parameter>' . $matches[1] . '</parameter>';
-				case 'not-assignable':
-					return '<parameter>' . $l->t('%s (restricted)', $matches[1]) . '</parameter>';
-				case 'invisible':
-					return '<parameter>' . $l->t('%s (invisible)', $matches[1]) . '</parameter>';
-			}
-		}
-
-		return $parameter;
-	}
-}
diff --git a/apps/systemtags/lib/Activity/Listener.php b/apps/systemtags/lib/Activity/Listener.php
index 69ba888c4fb..dbddf3c38bc 100644
--- a/apps/systemtags/lib/Activity/Listener.php
+++ b/apps/systemtags/lib/Activity/Listener.php
@@ -92,24 +92,26 @@ class Listener {
 		} else {
 			$actor = '';
 		}
+		$tag = $event->getTag();
 
 		$activity = $this->activityManager->generateEvent();
-		$activity->setApp(Extension::APP_NAME)
-			->setType(Extension::APP_NAME)
-			->setAuthor($actor);
+		$activity->setApp('systemtags')
+			->setType('systemtags')
+			->setAuthor($actor)
+			->setObject('systemtag', $tag->getId(), $tag->getName());
 		if ($event->getEvent() === ManagerEvent::EVENT_CREATE) {
-			$activity->setSubject(Extension::CREATE_TAG, [
+			$activity->setSubject(Provider::CREATE_TAG, [
 				$actor,
 				$this->prepareTagAsParameter($event->getTag()),
 			]);
 		} else if ($event->getEvent() === ManagerEvent::EVENT_UPDATE) {
-			$activity->setSubject(Extension::UPDATE_TAG, [
+			$activity->setSubject(Provider::UPDATE_TAG, [
 				$actor,
 				$this->prepareTagAsParameter($event->getTag()),
 				$this->prepareTagAsParameter($event->getTagBefore()),
 			]);
 		} else if ($event->getEvent() === ManagerEvent::EVENT_DELETE) {
-			$activity->setSubject(Extension::DELETE_TAG, [
+			$activity->setSubject(Provider::DELETE_TAG, [
 				$actor,
 				$this->prepareTagAsParameter($event->getTag()),
 			]);
@@ -181,10 +183,10 @@ class Listener {
 		}
 
 		$activity = $this->activityManager->generateEvent();
-		$activity->setApp(Extension::APP_NAME)
-			->setType(Extension::APP_NAME)
+		$activity->setApp('systemtags')
+			->setType('systemtags')
 			->setAuthor($actor)
-			->setObject($event->getObjectType(), $event->getObjectId());
+			->setObject($event->getObjectType(), (int) $event->getObjectId());
 
 		foreach ($users as $user => $path) {
 			$activity->setAffectedUser($user);
@@ -195,13 +197,13 @@ class Listener {
 					continue;
 				}
 				if ($event->getEvent() === MapperEvent::EVENT_ASSIGN) {
-					$activity->setSubject(Extension::ASSIGN_TAG, [
+					$activity->setSubject(Provider::ASSIGN_TAG, [
 						$actor,
 						$path,
 						$this->prepareTagAsParameter($tag),
 					]);
 				} else if ($event->getEvent() === MapperEvent::EVENT_UNASSIGN) {
-					$activity->setSubject(Extension::UNASSIGN_TAG, [
+					$activity->setSubject(Provider::UNASSIGN_TAG, [
 						$actor,
 						$path,
 						$this->prepareTagAsParameter($tag),
@@ -218,12 +220,11 @@ class Listener {
 	 * @return string
 	 */
 	protected function prepareTagAsParameter(ISystemTag $tag) {
-		if (!$tag->isUserVisible()) {
-			return '{{{' . $tag->getName() . '|||invisible}}}';
-		} else if (!$tag->isUserAssignable()) {
-			return '{{{' . $tag->getName() . '|||not-assignable}}}';
-		} else {
-			return '{{{' . $tag->getName() . '|||assignable}}}';
-		}
+		return json_encode([
+			'id' => $tag->getId(),
+			'name' => $tag->getName(),
+			'assignable' => $tag->isUserAssignable(),
+			'visible' => $tag->isUserVisible(),
+		]);
 	}
 }
diff --git a/apps/systemtags/lib/Activity/Provider.php b/apps/systemtags/lib/Activity/Provider.php
new file mode 100644
index 00000000000..9d85300d5be
--- /dev/null
+++ b/apps/systemtags/lib/Activity/Provider.php
@@ -0,0 +1,298 @@
+<?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\SystemTags\Activity;
+
+use OCP\Activity\IEvent;
+use OCP\Activity\IManager;
+use OCP\Activity\IProvider;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+
+class Provider implements IProvider {
+
+	const CREATE_TAG = 'create_tag';
+	const UPDATE_TAG = 'update_tag';
+	const DELETE_TAG = 'delete_tag';
+
+	const ASSIGN_TAG = 'assign_tag';
+	const UNASSIGN_TAG = 'unassign_tag';
+
+	/** @var IL10N */
+	protected $l;
+
+	/** @var IURLGenerator */
+	protected $url;
+
+	/** @var IManager */
+	protected $activityManager;
+
+	/**
+	 * @param IL10N $l
+	 * @param IURLGenerator $url
+	 * @param IManager $activityManager
+	 */
+	public function __construct(IL10N $l, IURLGenerator $url, IManager $activityManager) {
+		$this->l = $l;
+		$this->url = $url;
+		$this->activityManager = $activityManager;
+	}
+
+	/**
+	 * @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() !== 'systemtags') {
+			throw new \InvalidArgumentException();
+		}
+
+		if ($this->activityManager->isFormattingFilteredObject()) {
+			try {
+				return $this->parseShortVersion($event);
+			} catch (\InvalidArgumentException $e) {
+				// Ignore and simply use the long version...
+			}
+		}
+
+		return $this->parseLongVersion($event);
+	}
+
+	/**
+	 * @param IEvent $event
+	 * @return IEvent
+	 * @throws \InvalidArgumentException
+	 * @since 11.0.0
+	 */
+	public function parseShortVersion(IEvent $event) {
+		$parsedParameters = $this->getParameters($event);
+		$event->setIcon($this->url->getAbsoluteURL($this->url->imagePath('core', 'actions/tag.svg')));
+
+		if ($event->getSubject() === self::ASSIGN_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('Added system tag %1$s', [
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('Added system tag {systemtag}'), [
+						'systemtag' => $parsedParameters['systemtag'],
+					]);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s added system tag %2$s', [
+						$parsedParameters['actor']['name'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} added system tag {systemtag}'), [
+						'actor' => $parsedParameters['actor'],
+						'systemtag' => $parsedParameters['systemtag'],
+					]);
+			}
+		} else if ($event->getSubject() === self::UNASSIGN_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('Removed system tag %1$s', [
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('Removed system tag {systemtag}'), [
+						'systemtag' => $parsedParameters['systemtag'],
+					]);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s removed system tag %2$s', [
+						$parsedParameters['actor']['name'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} removed system tag {systemtag}'), [
+						'actor' => $parsedParameters['actor'],
+						'systemtag' => $parsedParameters['systemtag'],
+					]);
+			}
+		} else {
+			throw new \InvalidArgumentException();
+		}
+
+		return $event;
+	}
+
+	/**
+	 * @param IEvent $event
+	 * @return IEvent
+	 * @throws \InvalidArgumentException
+	 * @since 11.0.0
+	 */
+	public function parseLongVersion(IEvent $event) {
+		$parsedParameters = $this->getParameters($event);
+		$event->setIcon($this->url->getAbsoluteURL($this->url->imagePath('core', 'actions/tag.svg')));
+
+		if ($event->getSubject() === self::CREATE_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('You created system tag %1$s', [
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('You created system tag {systemtag}'), $parsedParameters);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s created system tag %2$s', [
+						$parsedParameters['actor']['name'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} created system tag {systemtag}'), $parsedParameters);
+			}
+		} else if ($event->getSubject() === self::DELETE_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('You deleted system tag %1$s', [
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('You deleted system tag {systemtag}'), $parsedParameters);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s deleted system tag %2$s', [
+						$parsedParameters['actor']['name'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} deleted system tag {systemtag}'), $parsedParameters);
+			}
+		} else if ($event->getSubject() === self::UPDATE_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('You updated system tag %2$s to %1$s', [
+						$this->generatePlainSystemTag($parsedParameters['newsystemtag']),
+						$this->generatePlainSystemTag($parsedParameters['oldsystemtag']),
+					]))
+					->setRichSubject($this->l->t('You updated system tag {oldsystemtag} to {newsystemtag}'), $parsedParameters);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s updated system tag %3$s to %2$s', [
+						$parsedParameters['actor']['name'],
+						$this->generatePlainSystemTag($parsedParameters['newsystemtag']),
+						$this->generatePlainSystemTag($parsedParameters['oldsystemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} updated system tag {oldsystemtag} to {newsystemtag}'), $parsedParameters);
+			}
+		} else if ($event->getSubject() === self::ASSIGN_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('You added system tag %2$s to %1$s', [
+						$parsedParameters['file']['path'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('You added system tag {systemtag} to {file}'), $parsedParameters);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s added system tag %3$s to %2$s', [
+						$parsedParameters['actor']['name'],
+						$parsedParameters['file']['path'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} added system tag {systemtag} to {file}'), $parsedParameters);
+			}
+		} else if ($event->getSubject() === self::UNASSIGN_TAG) {
+			if ($parsedParameters['actor']['id'] === $this->activityManager->getCurrentUserId()) {
+				$event->setParsedSubject($this->l->t('You removed system tag %2$s from %1$s', [
+						$parsedParameters['file']['path'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('You removed system tag {systemtag} from {file}'), $parsedParameters);
+			} else {
+				$event->setParsedSubject($this->l->t('%1$s removed system tag %3$s from %2$s', [
+						$parsedParameters['actor']['name'],
+						$parsedParameters['file']['path'],
+						$this->generatePlainSystemTag($parsedParameters['systemtag']),
+					]))
+					->setRichSubject($this->l->t('{actor} removed system tag {systemtag} from {file}'), $parsedParameters);
+			}
+		} else {
+			throw new \InvalidArgumentException();
+		}
+
+		return $event;
+	}
+
+	protected function getParameters(IEvent $event) {
+		$subject = $event->getSubject();
+		$parameters = $event->getSubjectParameters();
+
+		switch ($subject) {
+			case self::CREATE_TAG:
+			case self::DELETE_TAG:
+				return [
+					'actor' => $this->getUserParameter($parameters[0]),
+					'systemtag' => $this->getSystemTagParameter($parameters[1]),
+				];
+			case self::UPDATE_TAG:
+				return [
+					'actor' => $this->getUserParameter($parameters[0]),
+					'newsystemtag' => $this->getSystemTagParameter($parameters[1]),
+					'oldsystemtag' => $this->getSystemTagParameter($parameters[2]),
+				];
+			case self::ASSIGN_TAG:
+			case self::UNASSIGN_TAG:
+				return [
+					'actor' => $this->getUserParameter($parameters[0]),
+					'file' => $this->getFileParameter($event->getObjectId(), $parameters[1]),
+					'systemtag' => $this->getSystemTagParameter($parameters[2]),
+				];
+		}
+		return [];
+	}
+
+	protected function getFileParameter($id, $path) {
+		return [
+			'type' => 'file',
+			'id' => $id,
+			'name' => basename($path),
+			'path' => trim($path, '/'),
+		];
+	}
+
+	protected function getSystemTagParameter($parameter) {
+		$tagData = json_decode($parameter, true);
+		if ($tagData === null) {
+			list($name, $status) = explode('|||', substr($parameter, 3, -3));
+			$tagData = [
+				'id' => 0,// No way to recover the ID
+				'name' => $name,
+				'assignable' => $status === 'assignable',
+				'visible' => $status !== 'invisible',
+			];
+		}
+
+		return [
+			'type' => 'systemtag',
+			'id' => (int) $tagData['id'],
+			'name' => $tagData['name'],
+			'assignable' => $tagData['assignable'] ? '1' : '0',
+			'visibility' => $tagData['visible'] ? '1' : '0',
+		];
+	}
+
+	protected function getUserParameter($parameter) {
+		return [
+			'type' => 'user',
+			'id' => $parameter,
+			'name' => $parameter,// FIXME Use display name
+		];
+	}
+
+	protected function generatePlainSystemTag(array $parameter) {
+		if ($parameter['assignable'] === '1') {
+			return $parameter['name'];
+		} else if ($parameter['visibility'] === '1') {
+			return $this->l->t('%s (restricted)', $parameter['name']);
+		} else {
+			return $this->l->t('%s (invisible)', $parameter['name']);
+		}
+	}
+}
diff --git a/apps/systemtags/lib/Activity/Setting.php b/apps/systemtags/lib/Activity/Setting.php
new file mode 100644
index 00000000000..4cdb11b9c84
--- /dev/null
+++ b/apps/systemtags/lib/Activity/Setting.php
@@ -0,0 +1,98 @@
+<?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\SystemTags\Activity;
+
+
+use OCP\Activity\ISetting;
+use OCP\IL10N;
+
+class Setting implements ISetting {
+
+	/** @var IL10N */
+	protected $l;
+
+	/**
+	 * @param IL10N $l
+	 */
+	public function __construct(IL10N $l) {
+		$this->l = $l;
+	}
+
+	/**
+	 * @return string Lowercase a-z and underscore only identifier
+	 * @since 11.0.0
+	 */
+	public function getIdentifier() {
+		return 'systemtags';
+	}
+
+	/**
+	 * @return string A translated string
+	 * @since 11.0.0
+	 */
+	public function getName() {
+		return $this->l->t('<strong>System tags</strong> for a file have been modified');
+	}
+
+	/**
+	 * @return int whether the filter should be rather on the top or bottom of
+	 * the admin section. The filters are arranged in ascending order of the
+	 * priority values. It is required to return a value between 0 and 100.
+	 * @since 11.0.0
+	 */
+	public function getPriority() {
+		return 50;
+	}
+
+	/**
+	 * @return bool True when the option can be changed for the stream
+	 * @since 11.0.0
+	 */
+	public function canChangeStream() {
+		return true;
+	}
+
+	/**
+	 * @return bool True when the option can be changed for the stream
+	 * @since 11.0.0
+	 */
+	public function isDefaultEnabledStream() {
+		return true;
+	}
+
+	/**
+	 * @return bool True when the option can be changed for the mail
+	 * @since 11.0.0
+	 */
+	public function canChangeMail() {
+		return true;
+	}
+
+	/**
+	 * @return bool True when the option can be changed for the stream
+	 * @since 11.0.0
+	 */
+	public function isDefaultEnabledMail() {
+		return false;
+	}
+}
+