Sending unseen notifications as email periodically. Includes a new user settings page for notifications to configure this option.

Signed-off-by: Julien Barnoin <julien@berryandcloud.com>

6 files changed, 701 insertions, 0 deletions

diff --git a/lib/BackgroundJob/SendNotificationMails.php b/lib/BackgroundJob/SendNotificationMails.php
new file mode 100644
index 0000000..b7e5e86
--- /dev/null
+++ b/lib/BackgroundJob/SendNotificationMails.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2021 Julien Barnoin <julien@barnoin.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\Notifications\BackgroundJob;
+
+use OCP\BackgroundJob\TimedJob;
+use OCA\Notifications\MailNotifications;
+use OCP\AppFramework\Utility\ITimeFactory;
+
+class SendNotificationMails extends TimedJob {
+
+	/** @var ITimeFactory */
+	protected $timeFactory;
+	/** @var MailNotifications */
+	protected $mailNotifications;
+
+	public function __construct(ITimeFactory $timeFactory, MailNotifications $mailNotifications) {
+		parent::__construct($timeFactory);
+
+		// run every 15 min
+		$this->setInterval(60 * 15);
+
+		$this->timeFactory = $timeFactory;
+		$this->mailNotifications = $mailNotifications;
+	}
+
+	protected function run($argument) {
+		$this->mailNotifications->sendEmails();
+	}
+}
diff --git a/lib/Controller/SettingsController.php b/lib/Controller/SettingsController.php
new file mode 100644
index 0000000..4a4aedb
--- /dev/null
+++ b/lib/Controller/SettingsController.php
@@ -0,0 +1,90 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2021 Julien Barnoin <julien@barnoin.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\Notifications\Controller;
+
+use OCP\AppFramework\OCSController;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\IRequest;
+use OCP\IUserSession;
+
+class SettingsController extends OCSController {
+	/** @var \OCP\IConfig */
+	protected $config;
+
+	/** @var \OCP\IL10N */
+	protected $l10n;
+
+	/** @var string */
+	protected $user;
+
+	public function __construct(string $appName,
+								IRequest $request,
+								IConfig $config,
+								IL10N $l10n,
+								IUserSession $userSession) {
+		parent::__construct($appName, $request);
+		$this->config = $config;
+		$this->l10n = $l10n;
+		$this->user = $userSession->getUser()->getUID();
+	}
+
+	/**
+	 * @NoAdminRequired
+	 *
+	 * @param int $notify_setting_batchtime
+	 * @param bool $notifications_email_enabled
+	 * @return DataResponse
+	 */
+	public function personal(
+			int $notify_setting_batchtime = \OCA\Notifications\Settings\Personal::EMAIL_SEND_HOURLY,
+			bool $notifications_email_enabled = false
+	): DataResponse {
+		$email_batch_time = 3600;
+		if ($notify_setting_batchtime === \OCA\Notifications\Settings\Personal::EMAIL_SEND_DAILY) {
+			$email_batch_time = 3600 * 24;
+		} elseif ($notify_setting_batchtime === \OCA\Notifications\Settings\Personal::EMAIL_SEND_WEEKLY) {
+			$email_batch_time = 3600 * 24 * 7;
+		} elseif ($notify_setting_batchtime === \OCA\Notifications\Settings\Personal::EMAIL_SEND_ASAP) {
+			$email_batch_time = 0;
+		}
+
+		$this->config->setUserValue(
+			$this->user, 'notifications',
+			'notify_setting_batchtime',
+			(string) $email_batch_time
+		);
+		$this->config->setUserValue(
+			$this->user, 'notifications',
+			'notifications_email_enabled',
+			$notifications_email_enabled ? '1' : '0'
+		);
+
+		return new DataResponse([
+			'message' => $this->l10n->t('Your settings have been updated.'),
+		]);
+	}
+}
diff --git a/lib/Handler.php b/lib/Handler.php
index 6d92bfd..ff8b982 100644
--- a/lib/Handler.php
+++ b/lib/Handler.php
@@ -186,6 +186,38 @@ class Handler {
 	}
 
 	/**
+	 * Get the notifications after (and excluding) the given id
+	 *
+	 * @param int $startAfterId
+	 * @param string $user
+	 * @param int $limit
+	 * @return array [notification_id => INotification]
+	 * @throws NotificationNotFoundException
+	 */
+	public function getAfterId(int $startAfterId, string $user, $limit = 25): array {
+		$sql = $this->connection->getQueryBuilder();
+		$sql->select('*')
+			->from('notifications')
+			->orderBy('notification_id', 'DESC')
+			->setMaxResults($limit)
+			->where($sql->expr()->gt('notification_id', $sql->createNamedParameter($startAfterId)))
+			->andWhere($sql->expr()->eq('user', $sql->createNamedParameter($user)));
+		$statement = $sql->executeQuery();
+
+		$notifications = [];
+		while ($row = $statement->fetch()) {
+			try {
+				$notifications[(int)$row['notification_id']] = $this->notificationFromRow($row);
+			} catch (\InvalidArgumentException $e) {
+				continue;
+			}
+		}
+		$statement->closeCursor();
+
+		return $notifications;
+	}
+
+	/**
 	 * Return the notifications matching the given Notification
 	 *
 	 * @param INotification $notification
diff --git a/lib/MailNotifications.php b/lib/MailNotifications.php
new file mode 100644
index 0000000..e97f518
--- /dev/null
+++ b/lib/MailNotifications.php
@@ -0,0 +1,330 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @author Julien Barnoin <julien@barnoin.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\Notifications;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Defaults;
+use OCP\IConfig;
+use OCP\IDateTimeFormatter;
+use OCP\IURLGenerator;
+use OCP\IUserManager;
+use OCP\L10N\IFactory;
+use OCP\Mail\IMailer;
+use OCP\Mail\IMessage;
+use OCP\Notification\IManager;
+use OCP\Notification\INotification;
+use OCP\Notification\IAction;
+use OCP\Util;
+use Psr\Log\LoggerInterface;
+
+class MailNotifications {
+
+	/** @var IConfig */
+	private $config;
+
+	/** @var IManager */
+	private $manager;
+
+	/** @var Handler */
+	protected $handler;
+
+	/** @var IUserManager */
+	private $userManager;
+
+	/** @var LoggerInterface */
+	private $logger;
+
+	/** @var IMailer */
+	private $mailer;
+
+	/** @var IURLGenerator */
+	private $urlGenerator;
+
+	/** @var Defaults */
+	private $defaults;
+
+	/** @var IFactory */
+	private $l10nFactory;
+
+	/** @var IDateTimeFormatter */
+	private $dateFormatter;
+
+	/** @var ITimeFactory */
+	protected $timeFactory;
+
+	public const DEFAULT_BATCH_TIME = 3600 * 24;
+
+	public function __construct(
+		IConfig $config,
+		IManager $manager,
+		Handler $handler,
+		IUserManager $userManager,
+		LoggerInterface $logger,
+		IMailer $mailer,
+		IURLGenerator $urlGenerator,
+		Defaults $defaults,
+		IFactory $l10nFactory,
+		IDateTimeFormatter $dateTimeFormatter,
+		ITimeFactory $timeFactory
+	) {
+		$this->config = $config;
+		$this->manager = $manager;
+		$this->handler = $handler;
+		$this->userManager = $userManager;
+		$this->logger = $logger;
+		$this->mailer = $mailer;
+		$this->urlGenerator = $urlGenerator;
+		$this->defaults = $defaults;
+		$this->l10nFactory = $l10nFactory;
+		$this->dateFormatter = $dateTimeFormatter;
+		$this->timeFactory = $timeFactory;
+	}
+
+	/**
+	 * Send all due notification emails.
+	 */
+	public function sendEmails(): void {
+		// Get all users who enabled notification emails.
+		$users = $this->config->getUsersForUserValue('notifications', 'notifications_email_enabled', '1');
+
+		if (count($users) == 0) {
+			return;
+		}
+
+		// Batch-read settings that will be used to figure out who needs notifications sent out
+		$userBatchTimes = $this->config->getUserValueForUsers('notifications', 'notify_setting_batchtime', $users);
+		$userLastSendIds = $this->config->getUserValueForUsers('notifications', 'mail_last_send_id', $users);
+		$userLastSendTimes = $this->config->getUserValueForUsers('notifications', 'mail_last_send_time', $users);
+
+		$now = $this->timeFactory->getTime();
+
+		foreach ($users as $user) {
+			// Get the settings for this particular user, then check if we have notifications to email them
+			$batchTime = (array_key_exists($user, $userBatchTimes)) ? (int) $userBatchTimes[$user] : self::DEFAULT_BATCH_TIME;
+			$lastSendId = (array_key_exists($user, $userLastSendIds)) ? (int) $userLastSendIds[$user] : -1;
+			$lastSendTime = (array_key_exists($user, $userLastSendTimes)) ? (int) $userLastSendTimes[$user] : -1;
+
+			if (($now - $lastSendTime) >= $batchTime) {
+				// Enough time passed since last send for the user's desired interval between mails.
+				$notifications = $this->handler->getAfterId($lastSendId, $user);
+				if (!empty($notifications)) {
+					$this->sendEmailToUser($user, $notifications, $now);
+				}
+			}
+		}
+	}
+
+	/**
+	 * send an email to the user containing given list of notifications
+	 *
+	 * @param string $uid
+	 * @param INotification[] $notifications
+	 * @param int $now
+	 */
+	protected function sendEmailToUser(string $uid, array $notifications, int $now): void {
+		$lastSendId = array_key_first($notifications);
+
+		$language = $this->config->getUserValue($uid, 'core', 'lang', $this->config->getSystemValue('default_language', 'en'));
+
+		$preparedNotifications = [];
+		foreach ($notifications as $notification) {
+			/** @var INotification $preparedNotification */
+			try {
+				$preparedNotification = $this->manager->prepare($notification, $language);
+			} catch (\InvalidArgumentException $e) {
+				// The app was disabled, skip the notification
+				continue;
+			} catch (\Exception $e) {
+				$this->logger->error($e->getMessage());
+				continue;
+			}
+
+			$preparedNotifications[] = $preparedNotification;
+		}
+
+		if (count($preparedNotifications) > 0) {
+			$message = $this->prepareEmailMessage($uid, $preparedNotifications, $language);
+
+			if ($message != null) {
+				try {
+					$this->mailer->send($message);
+
+					// This is handled in config values based on how 'activity_digest_last_send' works,
+					//  but it would likely be a better choice to have this stored in a db like the activity mail queue?
+					$this->config->setUserValue($uid, 'notifications', 'mail_last_send_id', (string)$lastSendId);
+					$this->config->setUserValue($uid, 'notifications', 'mail_last_send_time', (string)$now);
+				} catch (\Exception $e) {
+					$this->logger->error($e->getMessage());
+				}
+			}
+		}
+	}
+
+	/**
+	 * prepare the contents of the email message containing the provided list of notifications
+	 *
+	 * @param string $uid
+	 * @param INotification[] $notifications
+	 * @param string $language
+	 * @return ?IMessage message contents
+	 */
+	protected function prepareEmailMessage(string $uid, array $notifications, string $language): ?IMessage {
+		$user = $this->userManager->get($uid);
+		$userEmailAddress = $user->getEMailAddress();
+
+		if (empty($userEmailAddress)) {
+			return null;
+		}
+
+		// Prepare our email template
+		$l10n = $this->l10nFactory->get('notifications', $language);
+
+		$template = $this->mailer->createEMailTemplate('notifications.EmailNotification', [
+			'displayname' => $user->getDisplayName(),
+			'url' => $this->urlGenerator->getAbsoluteURL('/')
+		]);
+
+		// Prepare email header
+		$template->addHeader();
+		$template->addHeading($l10n->t('Hello %s',[$user->getDisplayName()]), $l10n->t('Hello %s,',[$user->getDisplayName()]));
+
+		// Prepare email subject and body mentioning amount of notifications
+		$homeLink = '<a href="' . $this->urlGenerator->getAbsoluteURL('/') . '">' . htmlspecialchars($this->defaults->getName()) . '</a>';
+		$notificationsCount = count($notifications);
+		$template->setSubject($l10n->n('New notification for %s', '%n new notifications for %s', $notificationsCount, [$this->defaults->getName()]));
+		$template->addBodyText(
+			$l10n->n('You have a new notification for %s', 'You have %n new notifications for %s', $notificationsCount, [$homeLink]),
+			$l10n->n('You have a new notification for %s', 'You have %n new notifications for %s', $notificationsCount, [$this->urlGenerator->getAbsoluteURL('/')])
+		);
+
+		// Prepare email body with the content of missed notifications
+		// Notifications are assumed to be passed in in descending order (latest first). Reversing to present chronologically.
+		$notifications = array_reverse($notifications);
+
+		$timezone = $this->config->getUserValue($uid, 'core', 'timezone', date_default_timezone_get());
+
+		foreach ($notifications as $notification) {
+			$relativeDateTime = $this->dateFormatter->formatDateTimeRelativeDay($notification->getDateTime(), 'long', 'short', new \DateTimeZone($timezone), $l10n);
+			$template->addBodyListItem($this->getHTMLContents($notification), $relativeDateTime, $notification->getIcon(), $notification->getParsedSubject());
+
+			// Buttons probably were not intended for this, but it works ok enough for showing the idea.
+			$actions = $notification->getParsedActions();
+			foreach ($actions as $action) {
+				if ($action->getRequestType() === IAction::TYPE_WEB) {
+					$template->addBodyButton($action->getLabel(), $action->getLink());
+				}
+			}
+		}
+
+		// Prepare email footer
+		$template->addBodyText(
+			$l10n->t('You can change the frequency of these emails or disable them <a href="%s">here</a>.', $this->urlGenerator->linkToRouteAbsolute('settings.PersonalSettings.index', ['section' => 'notifications'])),
+			$l10n->t('You can change the frequency of these emails or disable them here: %s', $this->urlGenerator->linkToRouteAbsolute('settings.PersonalSettings.index', ['section' => 'notifications']))
+		);
+
+		$template->addFooter();
+
+		$message = $this->mailer->createMessage();
+		$message->useTemplate($template);
+		$message->setTo([$userEmailAddress => $user->getDisplayName()]);
+		$message->setFrom([Util::getDefaultEmailAddress('no-reply') => $this->defaults->getName()]);
+
+		return $message;
+	}
+
+	/**
+	 * return HTML to display this notification
+	 *
+	 * @param INotification $notification
+	 * @return string
+	 */
+	protected function getHTMLContents(INotification $notification): string {
+		$HTMLSubject = $this->getHTMLSubject($notification);
+		$link = $notification->getLink();
+		if ($link !== '') {
+			$HTMLSubject = '<a href="' . $link . '">' . $HTMLSubject . '</a>';
+		}
+
+		return $HTMLSubject . '<br>' . $this->getHTMLMessage($notification);
+	}
+
+	/**
+	 * return HTML to display the subject of this notification
+	 *
+	 * @param INotification $notification
+	 * @return string
+	 */
+	protected function getHTMLSubject(INotification $notification): string {
+		$contentString = htmlspecialchars($notification->getRichSubject());
+		if ($contentString === '') {
+			return htmlspecialchars($notification->getParsedSubject());
+		}
+
+		return $this->replaceRichParameters($notification->getRichSubjectParameters(), $contentString);
+	}
+
+	/**
+	 * return HTML to display the message body of this notification
+	 *
+	 * @param INotification $notification
+	 * @return string
+	 */
+	protected function getHTMLMessage(INotification $notification): string {
+		$contentString = htmlspecialchars($notification->getRichMessage());
+		if ($contentString === '') {
+			return htmlspecialchars($notification->getParsedMessage());
+		}
+
+		return $this->replaceRichParameters($notification->getRichMessageParameters(), $contentString);
+	}
+
+	/**
+	 * replace the given parameters in the input content string for display in an email
+	 *
+	 * @param array [string => string] $parameters
+	 * @param string $contentString
+	 * @return string $contentString with parameters processed
+	 */
+	protected function replaceRichParameters(array $parameters, string $contentString): string {
+		$placeholders = $replacements = [];
+		foreach ($parameters as $placeholder => $parameter) {
+			$placeholders[] = '{' . $placeholder . '}';
+
+			if ($parameter['type'] === 'file') {
+				$replacement = $parameter['path'];
+			} else {
+				$replacement = $parameter['name'];
+			}
+
+			if (isset($parameter['link'])) {
+				$replacements[] = '<a href="' . $parameter['link'] . '">' . htmlspecialchars($replacement) . '</a>';
+			} else {
+				$replacements[] = '<strong>' . htmlspecialchars($replacement) . '</strong>';
+			}
+		}
+
+		return str_replace($placeholders, $replacements, $contentString);
+	}
+}
diff --git a/lib/Settings/Personal.php b/lib/Settings/Personal.php
new file mode 100644
index 0000000..5e7aaa6
--- /dev/null
+++ b/lib/Settings/Personal.php
@@ -0,0 +1,112 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2021 Julien Barnoin <julien@barnoin.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\Notifications\Settings;
+
+use OCP\AppFramework\Http\TemplateResponse;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\Settings\ISettings;
+use OCP\IUserSession;
+use OCP\IInitialStateService;
+use OCP\Util;
+
+class Personal implements ISettings {
+	/** @var \OCP\IConfig */
+	protected $config;
+
+	/** @var \OCP\IL10N */
+	protected $l10n;
+
+	/** @var IUserSession */
+	private $session;
+
+	/** @var IInitialStateService */
+	private $initialStateService;
+
+	public const EMAIL_SEND_HOURLY = 0;
+	public const EMAIL_SEND_DAILY = 1;
+	public const EMAIL_SEND_WEEKLY = 2;
+	public const EMAIL_SEND_ASAP = 3;
+
+	public function __construct(IConfig $config,
+								IL10N $l10n,
+								IUserSession $session,
+								IInitialStateService $initialStateService) {
+		$this->config = $config;
+		$this->l10n = $l10n;
+
+		$this->session = $session;
+		$this->initialStateService = $initialStateService;
+	}
+
+	/**
+	 * @return TemplateResponse
+	 */
+	public function getForm(): TemplateResponse {
+		Util::addScript('notifications', 'notifications-userSettings');
+		
+		$settingBatchTime = Personal::EMAIL_SEND_HOURLY;
+		$user = $this->session->getUser()->getUID();
+		$currentSetting = (int) $this->config->getUserValue($user, 'notifications', 'notify_setting_batchtime', 3600 * 24);
+
+		if ($currentSetting === 3600 * 24 * 7) {
+			$settingBatchTime = Personal::EMAIL_SEND_WEEKLY;
+		} elseif ($currentSetting === 3600 * 24) {
+			$settingBatchTime = Personal::EMAIL_SEND_DAILY;
+		} elseif ($currentSetting === 0) {
+			$settingBatchTime = Personal::EMAIL_SEND_ASAP;
+		}
+
+		$emailEnabled = true;
+		
+		$this->initialStateService->provideInitialState('notifications', 'config', [
+			'setting' => 'personal',
+			'is_email_set' => !empty($this->config->getUserValue($user, 'settings', 'email', '')),
+			'email_enabled' => $emailEnabled,
+			'setting_batchtime' => $settingBatchTime,
+			'notifications_email_enabled' => $this->config->getUserValue($user, 'notifications', 'notifications_email_enabled') == 1
+		]);
+
+		return new TemplateResponse('notifications', 'settings/personal');
+	}
+
+	/**
+	 * @return string the section ID, e.g. 'sharing'
+	 */
+	public function getSection(): string {
+		return 'notifications';
+	}
+
+	/**
+	 * @return int whether the form should be rather on the top or bottom of
+	 * the admin section. The forms are arranged in ascending order of the
+	 * priority values. It is required to return a value between 0 and 100.
+	 *
+	 * E.g.: 70
+	 */
+	public function getPriority(): int {
+		return 55;
+	}
+}
diff --git a/lib/Settings/PersonalSection.php b/lib/Settings/PersonalSection.php
new file mode 100644
index 0000000..16b544a
--- /dev/null
+++ b/lib/Settings/PersonalSection.php
@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2021 Julien Barnoin <julien@barnoin.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\Notifications\Settings;
+
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\Settings\IIconSection;
+
+class PersonalSection implements IIconSection {
+	/** @var IL10N */
+	private $l;
+
+	/** @var IURLGenerator */
+	private $url;
+
+	public function __construct(IURLGenerator $url, IL10N $l) {
+		$this->url = $url;
+		$this->l = $l;
+	}
+
+	/**
+	 * returns the relative path to an 16*16 icon describing the section.
+	 * e.g. '/core/img/places/files.svg'
+	 *
+	 * @returns string
+	 * @since 12
+	 */
+	public function getIcon(): string {
+		return $this->url->imagePath('notifications', 'notifications-dark.svg');
+	}
+
+	/**
+	 * returns the ID of the section. It is supposed to be a lower case string,
+	 * e.g. 'ldap'
+	 *
+	 * @returns string
+	 * @since 9.1
+	 */
+	public function getID(): string {
+		return 'notifications';
+	}
+
+	/**
+	 * returns the translated name as it should be displayed, e.g. 'LDAP / AD
+	 * integration'. Use the L10N service to translate it.
+	 *
+	 * @return string
+	 * @since 9.1
+	 */
+	public function getName(): string {
+		return $this->l->t('Notifications');
+	}
+
+	/**
+	 * @return int whether the form should be rather on the top or bottom of
+	 * the settings navigation. The sections are arranged in ascending order of
+	 * the priority values. It is required to return a value between 0 and 99.
+	 *
+	 * E.g.: 70
+	 * @since 9.1
+	 */
+	public function getPriority(): int {
+		return 10;
+	}
+}