Add an event merger and use it for the files activities

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

1 files changed, 64 insertions, 0 deletions

diff --git a/lib/public/Activity/IEventMerger.php b/lib/public/Activity/IEventMerger.php
new file mode 100644
index 00000000000..8bd8e540770
--- /dev/null
+++ b/lib/public/Activity/IEventMerger.php
@@ -0,0 +1,64 @@
+<?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 OCP\Activity;
+
+
+/**
+ * Interface EventMerger
+ *
+ * @package OCP\Activity
+ * @since 11.0
+ */
+interface IEventMerger {
+
+	/**
+	 * Combines two events when possible to have grouping:
+	 *
+	 * Example1: Two events with subject '{user} created {file}' and
+	 * $mergeParameter file with different file and same user will be merged
+	 * to '{user} created {file1} and {file2}' and the childEvent on the return
+	 * will be set, if the events have been merged.
+	 *
+	 * Example2: Two events with subject '{user} created {file}' and
+	 * $mergeParameter file with same file and same user will be merged to
+	 * '{user} created {file1}' and the childEvent on the return will be set, if
+	 * the events have been merged.
+	 *
+	 * The following requirements have to be met, in order to be merged:
+	 * - Both events need to have the same `getApp()`
+	 * - Both events must not have a message `getMessage()`
+	 * - Both events need to have the same subject `getSubject()`
+	 * - Both events need to have the same object type `getObjectType()`
+	 * - The time difference between both events must not be bigger then 3 hours
+	 * - Only up to 5 events can be merged.
+	 * - All parameters apart from such starting with $mergeParameter must be
+	 *   the same for both events.
+	 *
+	 * @param string $mergeParameter
+	 * @param IEvent $event
+	 * @param IEvent|null $previousEvent
+	 * @return IEvent
+	 * @since 11.0
+	 */
+	public function mergeEvents($mergeParameter, IEvent $event, IEvent $previousEvent = null);
+
+}