Watch events (#1367)

Watch current poll for updates an apply immediately

11 files changed, 489 insertions, 44 deletions

diff --git a/lib/Controller/ResponseHandle.php b/lib/Controller/ResponseHandle.php
index 39b4e91d..350ff267 100644
--- a/lib/Controller/ResponseHandle.php
+++ b/lib/Controller/ResponseHandle.php
@@ -28,6 +28,7 @@ use OCP\AppFramework\Http;
 use OCP\AppFramework\Http\DataResponse;
 
 use OCP\AppFramework\Db\DoesNotExistException;
+use OCA\Polls\Exceptions\NoUpdatesException;
 use OCA\Polls\Exceptions\Exception;
 
 trait ResponseHandle {
@@ -45,6 +46,18 @@ trait ResponseHandle {
 	}
 
 	/**
+	 * response
+	 * @NoAdminRequired
+	 */
+	protected function responseLong(Closure $callback): DataResponse {
+		try {
+			return new DataResponse($callback(), Http::STATUS_OK);
+		} catch (NoUpdatesException $e) {
+			return new DataResponse([], Http::STATUS_NOT_MODIFIED);
+		}
+	}
+
+	/**
 	 * responseCreate
 	 * @NoAdminRequired
 	 */
diff --git a/lib/Controller/WatchController.php b/lib/Controller/WatchController.php
new file mode 100644
index 00000000..a035bcf4
--- /dev/null
+++ b/lib/Controller/WatchController.php
@@ -0,0 +1,67 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Vinzenz Rosenkranz <vinzenz.rosenkranz@gmail.com>
+ *
+ * @author René Gieling <github@dartcafe.de>
+ *
+ * @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\Polls\Controller;
+
+use OCP\IRequest;
+use OCP\AppFramework\Controller;
+use OCP\AppFramework\Http\DataResponse;
+use OCA\Polls\Exceptions\NoUpdatesException;
+use OCA\Polls\Service\WatchService;
+
+class WatchController extends Controller {
+
+	/** @var WatchService */
+	private $watchService;
+
+	use ResponseHandle;
+
+	public function __construct(
+		string $appName,
+		IRequest $request,
+		WatchService $watchService
+	) {
+		parent::__construct($appName, $request);
+		$this->watchService = $watchService;
+	}
+
+	/**
+	 * Watch poll for updates
+	 * @NoAdminRequired
+	 * @NoCSRFRequired
+	 */
+	public function watchSinglePoll(int $pollId, ?int $offset = 0): DataResponse {
+		return $this->responseLong(function () use ($pollId, $offset) {
+			$start = time();
+			$timeout = 30;
+			while (empty($updates) && time() <= $start + $timeout) {
+				sleep(1);
+				$updates = $this->watchService->getUpdates($pollId, $offset ? $offset : $start);
+			}
+			if (empty($updates)) {
+				throw new NoUpdatesException;
+			}
+			return ['updates' => $updates];
+		});
+	}
+}
diff --git a/lib/Db/Watch.php b/lib/Db/Watch.php
new file mode 100644
index 00000000..ea6a518c
--- /dev/null
+++ b/lib/Db/Watch.php
@@ -0,0 +1,63 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Vinzenz Rosenkranz <vinzenz.rosenkranz@gmail.com>
+ *
+ * @author René Gieling <githung@dartcafe.de>
+ *
+ * @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\Polls\Db;
+
+use JsonSerializable;
+
+use OCP\AppFramework\Db\Entity;
+
+/**
+ * @method int getId()
+ * @method void setId(integer $value)
+ * @method int getPollId()
+ * @method void setPollId(integer $value)
+ * @method string getTable()
+ * @method void setTable(string $value)
+ * @method string getUpdated()
+ * @method void setUpdated(string $value)
+ */
+class Watch extends Entity implements JsonSerializable {
+	public const OBJECT_POLLS = "polls";
+	public const OBJECT_VOTES = "votes";
+	public const OBJECT_OPTIONS = "options";
+	public const OBJECT_COMMENTS = "comments";
+
+	/** @var int $pollId */
+	protected $pollId;
+
+	/** @var string $tableId */
+	protected $table;
+
+	/** @var string $updated */
+	protected $updated;
+
+	public function jsonSerialize() {
+		return [
+			'id' => intval($this->id),
+			'pollId' => intval($this->pollId),
+			'table' => $this->table,
+			'updated' => $this->updated,
+		];
+	}
+}
diff --git a/lib/Db/WatchMapper.php b/lib/Db/WatchMapper.php
new file mode 100644
index 00000000..38bf18b9
--- /dev/null
+++ b/lib/Db/WatchMapper.php
@@ -0,0 +1,75 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Vinzenz Rosenkranz <vinzenz.rosenkranz@gmail.com>
+ *
+ * @author Vinzenz Rosenkranz <vinzenz.rosenkranz@gmail.com>
+ * @author René Gieling <github@dartcafe.de>
+ *
+ * @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\Polls\Db;
+
+use OCP\IDBConnection;
+use OCP\AppFramework\Db\QBMapper;
+
+/**
+ * @template-extends QBMapper<Watch>
+ */
+class WatchMapper extends QBMapper {
+	public function __construct(IDBConnection $db) {
+		parent::__construct($db, 'polls_watch', '\OCA\Polls\Db\Watch');
+	}
+
+	/**
+	 * @throws \OCP\AppFramework\Db\DoesNotExistException if not found
+	 * @return Watch[]
+	 */
+	public function findUpdatesForPollId(int $pollId, int $offset): array {
+		$qb = $this->db->getQueryBuilder();
+
+		$qb->select('*')
+		   ->from($this->getTableName())
+		   ->where(
+			   $qb->expr()->eq('poll_id', $qb->createNamedParameter($pollId))
+		   )
+		   ->andWhere(
+			   $qb->expr()->gt('updated', $qb->createNamedParameter($offset))
+		   );
+
+		return $this->findEntities($qb);
+	}
+
+	/**
+	 * @throws \OCP\AppFramework\Db\DoesNotExistException if not found
+	 * @return Watch
+	 */
+	public function findForPollIdAndTable(int $pollId, string $table): Watch {
+		$qb = $this->db->getQueryBuilder();
+
+		$qb->select('*')
+		   ->from($this->getTableName())
+		   ->where(
+			   $qb->expr()->eq('poll_id', $qb->createNamedParameter($pollId))
+		   )
+		   ->andWhere(
+			   $qb->expr()->eq('table', $qb->createNamedParameter($table))
+		   );
+
+		return $this->findEntity($qb);
+	}
+}
diff --git a/lib/Exceptions/NoUpdatesException.php b/lib/Exceptions/NoUpdatesException.php
new file mode 100644
index 00000000..a0f836c6
--- /dev/null
+++ b/lib/Exceptions/NoUpdatesException.php
@@ -0,0 +1,32 @@
+<?php
+/**
+ * @copyright Copyright (c) 2020 René Gieling <github@dartcafe.de>
+ *
+ * @author René Gieling <github@dartcafe.de>
+ *
+ * @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\Polls\Exceptions;
+
+use OCP\AppFramework\Http;
+
+class NoUpdatesException extends Exception {
+	public function __construct($e = 'No updates') {
+		parent::__construct($e, Http::STATUS_NOT_MODIFIED);
+	}
+}
diff --git a/lib/Migration/Version0108Date20210127135802.php b/lib/Migration/Version0108Date20210127135802.php
new file mode 100644
index 00000000..1351abed
--- /dev/null
+++ b/lib/Migration/Version0108Date20210127135802.php
@@ -0,0 +1,79 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 René Gieling <github@dartcafe.de>
+ *
+ * @author René Gieling <github@dartcafe.de>
+ *
+ * @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\Polls\Migration;
+
+use OCP\DB\ISchemaWrapper;
+use OCP\IConfig;
+use OCP\IDBConnection;
+use OCP\Migration\SimpleMigrationStep;
+use OCP\Migration\IOutput;
+
+class Version0108Date20210127135802 extends SimpleMigrationStep {
+
+	/** @var IDBConnection */
+	protected $connection;
+
+	/** @var IConfig */
+	protected $config;
+
+	public function __construct(IDBConnection $connection, IConfig $config) {
+		$this->connection = $connection;
+		$this->config = $config;
+	}
+
+	public function changeSchema(IOutput $output, \Closure $schemaClosure, array $options) {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+		if (!$schema->hasTable('polls_watch')) {
+			$table = $schema->createTable('polls_watch');
+			$table->addColumn('id', 'integer', [
+				'autoincrement' => true,
+				'notnull' => true,
+			]);
+			$table->addColumn('table', 'string', [
+				'length' => 64,
+				'notnull' => true,
+				'default' => ''
+			]);
+			$table->addColumn('poll_id', 'integer', [
+				'length' => 11,
+				'notnull' => true,
+				'default' => 0
+			]);
+			$table->addColumn('updated', 'integer', [
+				'length' => 11,
+				'notnull' => true,
+				'default' => 0
+			]);
+			$table->setPrimaryKey(['id']);
+		} else {
+			$table = $schema->getTable('polls_watch');
+		}
+
+		if (!$table->hasIndex('UNIQ_watch')) {
+			$table->addUniqueIndex(['poll_id', 'table'], 'UNIQ_watch');
+		}
+		return $schema;
+	}
+}
diff --git a/lib/Service/CommentService.php b/lib/Service/CommentService.php
index 90e71b23..2619311f 100644
--- a/lib/Service/CommentService.php
+++ b/lib/Service/CommentService.php
@@ -25,32 +25,38 @@ namespace OCA\Polls\Service;
 
 use OCA\Polls\Db\Comment;
 use OCA\Polls\Db\CommentMapper;
+use OCA\Polls\Db\Watch;
 use OCA\Polls\Model\Acl;
 
 class CommentService {
 
+	/** @var Acl */
+	private $acl;
+
+	/** @var AnonymizeService */
+	private $anonymizer;
+
 	/** @var CommentMapper */
 	private $commentMapper;
 
 	/** @var Comment */
 	private $comment;
 
-	/** @var AnonymizeService */
-	private $anonymizer;
-
-	/** @var Acl */
-	private $acl;
+	/** @var WatchService */
+	private $watchService;
 
 	public function __construct(
+		Acl $acl,
+		AnonymizeService $anonymizer,
 		CommentMapper $commentMapper,
 		Comment $comment,
-		AnonymizeService $anonymizer,
-		Acl $acl
+		WatchService $watchService
 	) {
+		$this->acl = $acl;
+		$this->anonymizer = $anonymizer;
 		$this->commentMapper = $commentMapper;
 		$this->comment = $comment;
-		$this->anonymizer = $anonymizer;
-		$this->acl = $acl;
+		$this->watchService = $watchService;
 	}
 
 	/**
@@ -88,6 +94,7 @@ class CommentService {
 		$this->comment->setDt(date('Y-m-d H:i:s'));
 		$this->comment->setTimestamp(time());
 		$this->comment = $this->commentMapper->insert($this->comment);
+		$this->watchService->writeUpdate($this->comment->getPollId(), Watch::OBJECT_COMMENTS);
 		return $this->comment;
 	}
 
@@ -104,6 +111,7 @@ class CommentService {
 		}
 
 		$this->commentMapper->delete($this->comment);
+		$this->watchService->writeUpdate($this->comment->getPollId(), Watch::OBJECT_COMMENTS);
 		return $this->comment;
 	}
 }
diff --git a/lib/Service/OptionService.php b/lib/Service/OptionService.php
index 4e09440a..51bf2c98 100644
--- a/lib/Service/OptionService.php
+++ b/lib/Service/OptionService.php
@@ -34,32 +34,38 @@ use OCA\Polls\Db\OptionMapper;
 use OCA\Polls\Db\Option;
 use OCA\Polls\Db\PollMapper;
 use OCA\Polls\Db\Poll;
+use OCA\Polls\Db\Watch;
 use OCA\Polls\Model\Acl;
 
 class OptionService {
 
-	/** @var OptionMapper */
-	private $optionMapper;
+	/** @var Acl */
+	private $acl;
 
 	/** @var Option */
 	private $option;
 
+	/** @var OptionMapper */
+	private $optionMapper;
+
 	/** @var PollMapper */
 	private $pollMapper;
 
-	/** @var Acl */
-	private $acl;
+	/** @var WatchService */
+	private $watchService;
 
 	public function __construct(
-		OptionMapper $optionMapper,
+		Acl $acl,
 		Option $option,
+		OptionMapper $optionMapper,
 		PollMapper $pollMapper,
-		Acl $acl
+		WatchService $watchService
 	) {
-		$this->optionMapper = $optionMapper;
+		$this->acl = $acl;
 		$this->option = $option;
+		$this->optionMapper = $optionMapper;
 		$this->pollMapper = $pollMapper;
-		$this->acl = $acl;
+		$this->watchService = $watchService;
 	}
 
 	/**
@@ -116,10 +122,12 @@ class OptionService {
 		$this->setOption($timestamp, $pollOptionText);
 
 		try {
-			return $this->optionMapper->insert($this->option);
+			$this->option = $this->optionMapper->insert($this->option);
+			$this->watchService->writeUpdate($this->option->getPollId(), Watch::OBJECT_OPTIONS);
 		} catch (UniqueConstraintViolationException $e) {
 			throw new DuplicateEntryException('This option already exists');
 		}
+		return $this->option;
 	}
 
 	/**
@@ -132,7 +140,9 @@ class OptionService {
 		$this->acl->setPollId($this->option->getPollId())->request(Acl::PERMISSION_EDIT);
 		$this->setOption($timestamp, $pollOptionText);
 
-		return $this->optionMapper->update($this->option);
+		$this->option = $this->optionMapper->update($this->option);
+		$this->watchService->writeUpdate($this->option->getPollId(), Watch::OBJECT_OPTIONS);
+		return $this->option;
 	}
 
 	/**
@@ -144,6 +154,7 @@ class OptionService {
 		$this->option = $this->optionMapper->find($optionId);
 		$this->acl->setPollId($this->option->getPollId())->request(Acl::PERMISSION_EDIT);
 		$this->optionMapper->delete($this->option);
+		$this->watchService->writeUpdate($this->option->getPollId(), Watch::OBJECT_OPTIONS);
 
 		return $this->option;
 	}
@@ -163,7 +174,9 @@ class OptionService {
 			$this->option->setConfirmed(time());
 		}
 
-		return $this->optionMapper->update($this->option);
+		$this->option = $this->optionMapper->update($this->option);
+		$this->watchService->writeUpdate($this->option->getPollId(), Watch::OBJECT_OPTIONS);
+		return $this->option;
 	}
 
 	/**
@@ -197,6 +210,7 @@ class OptionService {
 				\OC::$server->getLogger()->warning('skip adding ' . $baseDate->format('c') . 'for pollId' . $this->option->getPollId() . '. Option alredy exists.');
 			}
 		}
+		$this->watchService->writeUpdate($this->option->getPollId(), Watch::OBJECT_OPTIONS);
 		return $this->optionMapper->findByPoll($this->option->getPollId());
 	}
 
@@ -251,6 +265,7 @@ class OptionService {
 			}
 		}
 
+		$this->watchService->writeUpdate($pollId, Watch::OBJECT_OPTIONS);
 		return $this->optionMapper->findByPoll($pollId);
 	}
 
@@ -287,6 +302,7 @@ class OptionService {
 			$this->optionMapper->update($option);
 		}
 
+		$this->watchService->writeUpdate($this->option->getPollId(), Watch::OBJECT_OPTIONS);
 		return $this->optionMapper->findByPoll($this->option->getPollId());
 	}
 
diff --git a/lib/Service/PollService.php b/lib/Service/PollService.php
index 71c21d26..e65e7120 100644
--- a/lib/Service/PollService.php
+++ b/lib/Service/PollService.php
@@ -30,12 +30,12 @@ use OCA\Polls\Exceptions\InvalidShowResultsException;
 use OCA\Polls\Exceptions\InvalidPollTypeException;
 use OCA\Polls\Exceptions\NotAuthorizedException;
 
-
 use OCA\Polls\Db\Log;
 use OCA\Polls\Db\PollMapper;
 use OCA\Polls\Db\Poll;
 use OCA\Polls\Db\VoteMapper;
 use OCA\Polls\Db\Vote;
+use OCA\Polls\Db\Watch;
 use OCA\Polls\Model\Acl;
 
 class PollService {
@@ -52,6 +52,9 @@ class PollService {
 	/** @var VoteMapper */
 	private $voteMapper;
 
+	/** @var WatchService */
+	private $watchService;
+
 	/** @var Vote */
 	private $vote;
 
@@ -73,6 +76,7 @@ class PollService {
 		Poll $poll,
 		VoteMapper $voteMapper,
 		Vote $vote,
+		WatchService $watchService,
 		LogService $logService,
 		NotificationService $notificationService,
 		MailService $mailService,
@@ -82,6 +86,7 @@ class PollService {
 		$this->userId = $UserId;
 		$this->poll = $poll;
 		$this->voteMapper = $voteMapper;
+		$this->watchService = $watchService;
 		$this->vote = $vote;
 		$this->logService = $logService;
 		$this->notificationService = $notificationService;
@@ -206,6 +211,7 @@ class PollService {
 		$this->poll->setImportant(0);
 		$this->poll = $this->pollMapper->insert($this->poll);
 
+		$this->watchService->writeUpdate($this->poll->getId(), Watch::OBJECT_POLLS);
 		$this->logService->setLog($this->poll->getId(), Log::MSG_ID_ADDPOLL);
 
 		return $this->poll;
@@ -234,6 +240,7 @@ class PollService {
 		$this->poll->deserializeArray($poll);
 
 		$this->pollMapper->update($this->poll);
+		$this->watchService->writeUpdate($this->poll->getId(), Watch::OBJECT_POLLS);
 		$this->logService->setLog($this->poll->getId(), Log::MSG_ID_UPDATEPOLL);
 
 		return $this->poll;
@@ -256,6 +263,7 @@ class PollService {
 		}
 
 		$this->poll = $this->pollMapper->update($this->poll);
+		$this->watchService->writeUpdate($this->poll->getId(), Watch::OBJECT_POLLS);
 		$this->logService->setLog($this->poll->getId(), Log::MSG_ID_DELETEPOLL);
 
 		if ($this->userId !== $this->poll->getOwner()) {
@@ -283,6 +291,7 @@ class PollService {
 		$this->acl->setPoll($this->poll)->request(Acl::PERMISSION_DELETE);
 
 		$this->pollMapper->delete($this->poll);
+		$this->watchService->writeUpdate($this->poll->getId(), Watch::OBJECT_POLLS);
 
 		if ($this->userId !== $this->poll->getOwner()) {
 			// send notification to the original owner
@@ -327,7 +336,9 @@ class PollService {
 		$this->poll->setAdminAccess($origin->getAdminAccess());
 		$this->poll->setImportant($origin->getImportant());
 
-		return $this->pollMapper->insert($this->poll);
+		$this->poll = $this->pollMapper->insert($this->poll);
+		$this->watchService->writeUpdate($this->poll->getId(), Watch::OBJECT_POLLS);
+		return $this->poll;
 	}
 
 	/**
diff --git a/lib/Service/VoteService.php b/lib/Service/VoteService.php
index f867c46f..415517c1 100644
--- a/lib/Service/VoteService.php
+++ b/lib/Service/VoteService.php
@@ -32,12 +32,22 @@ use OCA\Polls\Db\OptionMapper;
 use OCA\Polls\Db\VoteMapper;
 use OCA\Polls\Db\PollMapper;
 use OCA\Polls\Db\Vote;
+use OCA\Polls\Db\Watch;
 use OCA\Polls\Model\Acl;
 
 class VoteService {
 
-	/** @var VoteMapper */
-	private $voteMapper;
+	/** @var Acl */
+	private $acl;
+
+	/** @var AnonymizeService */
+	private $anonymizer;
+
+	/** @var LogService */
+	private $logService;
+
+	/** @var OptionMapper */
+	private $optionMapper;
 
 	/** @var PollMapper */
 	private $pollMapper;
@@ -45,34 +55,31 @@ class VoteService {
 	/** @var Vote */
 	private $vote;
 
-	/** @var OptionMapper */
-	private $optionMapper;
-
-	/** @var AnonymizeService */
-	private $anonymizer;
+	/** @var VoteMapper */
+	private $voteMapper;
 
-	/** @var LogService */
-	private $logService;
+	/** @var WatchService */
+	private $watchService;
 
-	/** @var Acl */
-	private $acl;
 
 	public function __construct(
-		VoteMapper $voteMapper,
-		PollMapper $pollMapper,
-		Vote $vote,
-		OptionMapper $optionMapper,
+		Acl $acl,
 		AnonymizeService $anonymizer,
 		LogService $logService,
-		Acl $acl
+		OptionMapper $optionMapper,
+		PollMapper $pollMapper,
+		Vote $vote,
+		VoteMapper $voteMapper,
+		WatchService $watchService
 	) {
-		$this->voteMapper = $voteMapper;
-		$this->pollMapper = $pollMapper;
-		$this->vote = $vote;
-		$this->optionMapper = $optionMapper;
+		$this->acl = $acl;
 		$this->anonymizer = $anonymizer;
 		$this->logService = $logService;
-		$this->acl = $acl;
+		$this->optionMapper = $optionMapper;
+		$this->pollMapper = $pollMapper;
+		$this->vote = $vote;
+		$this->voteMapper = $voteMapper;
+		$this->watchService = $watchService;
 	}
 
 	/**
@@ -172,7 +179,8 @@ class VoteService {
 			$this->vote->setVoteAnswer($setTo);
 			$this->voteMapper->insert($this->vote);
 		}
-		$this->logService->setLog($this->acl->getPollId(), Log::MSG_ID_SETVOTE, $this->vote->getUserId());
+		$this->logService->setLog($this->vote->getPollId(), Log::MSG_ID_SETVOTE, $this->vote->getUserId());
+		$this->watchService->writeUpdate($this->vote->getPollId(), Watch::OBJECT_VOTES);
 		return $this->vote;
 	}
 
@@ -182,6 +190,7 @@ class VoteService {
 	public function delete(int $pollId, string $userId): string {
 		$this->acl->setPollId($pollId)->request(Acl::PERMISSION_EDIT);
 		$this->voteMapper->deleteByPollAndUser($pollId, $userId);
+		$this->watchService->writeUpdate($pollId, Watch::OBJECT_VOTES);
 		return $userId;
 	}
 }
diff --git a/lib/Service/WatchService.php b/lib/Service/WatchService.php
new file mode 100644
index 00000000..362fa637
--- /dev/null
+++ b/lib/Service/WatchService.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Vinzenz Rosenkranz <vinzenz.rosenkranz@gmail.com>
+ *
+ * @author René Gieling <github@dartcafe.de>
+ *
+ * @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\Polls\Service;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+
+use OCA\Polls\Db\Watch;
+use OCA\Polls\Db\WatchMapper;
+
+class WatchService {
+
+	/** @var WatchMapper */
+	private $watchMapper;
+
+	/** @var Watch */
+	private $watch;
+
+	public function __construct(
+		WatchMapper $watchMapper
+	) {
+		$this->watchMapper = $watchMapper;
+	}
+
+	/**
+	 * @return Watch[]
+	 */
+	public function getUpdates(int $pollId, int $offset): array {
+		try {
+			return $this->watchMapper->findUpdatesForPollId($pollId, $offset);
+		} catch (DoesNotExistException $e) {
+			return [];
+		}
+	}
+
+	/**
+	 * @return Watch
+	 */
+	public function writeUpdate(int $pollId, string $table): Watch {
+		try {
+			$this->watch = $this->watchMapper->findForPollIdAndTable($pollId, $table);
+		} catch (DoesNotExistException $e) {
+			$this->watch = new Watch();
+			$this->watch->setPollId($pollId);
+			$this->watch->setTable($table);
+			$this->watch = $this->watchMapper->insert($this->watch);
+		}
+
+		$this->watch->setUpdated(time());
+		return $this->watchMapper->update($this->watch);
+	}
+}