Use display name for users and groups

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/Db/User.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * @copyright Copyright (c) 2017 Julius Härtl <jus@bitgrid.net>
+ *
+ * @author Julius Härtl <jus@bitgrid.net>
+ *
+ * @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\Deck\Db;
+
+use OCP\IGroup;
+use OCP\IUser;
+
+class User extends RelationalObject {
+
+	public function __construct(IUser $user = null) {
+		$primaryKey = $user->getUID();
+		parent::__construct($primaryKey, $user);
+	}
+
+	public function getObjectSerialization() {
+		return [
+			'uid' => $this->object->getUID(),
+			'displayname' => $this->object->getDisplayName()
+		];
+	}
+}