[PoC] Allow apps to add their own collection to the calendar-home-set

apps/dav/lib/CalDAV/ICalendarHomePlugin.php

@@ -0,0 +1,44 @@
+<?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\DAV\CalDAV;
+
+/**
+ * Interface that allows a SabreDAV plugin to register a calendar home to be
+ * returned as calendar-home-set
+ */
+interface ICalendarHomePlugin {
+
+	/**
+	 * Returns the path to a principal's calendar home.
+	 *
+	 * The return url must not end with a slash.
+	 * This function should return null in case a principal did not have
+	 * a calendar home.
+	 *
+	 * @param string $principalUrl
+	 * @return string|null
+	 */
+	public function getCalendarHomeForPrincipal($principalUrl);
+
+}

apps/dav/lib/CalDAV/Plugin.php

@@ -1,5 +1,6 @@
 <?php
 /**
+ * @author Julius Härtl <jus@bitgrid.net>
  * @author Thomas Müller <thomas.mueller@tmit.eu>
  *
  * @copyright Copyright (c) 2016, ownCloud GmbH.
@@ -21,21 +22,69 @@
 
 namespace OCA\DAV\CalDAV;
 
-use Sabre\HTTP\URLUtil;
+use Sabre\DAV\Server;
+use Sabre\DAV;
+use Sabre\DAV\Xml\Property\LocalHref;
+use Sabre\DAVACL\IPrincipal;
 
-class Plugin extends \Sabre\CalDAV\Plugin {
+class Plugin extends \Sabre\CalDAV\Plugin implements ICalendarHomePlugin {
 
 	/**
-	 * @inheritdoc
+	 * Initializes the plugin
+	 *
+	 * @param Server $server
+	 * @return void
 	 */
-	function getCalendarHomeForPrincipal($principalUrl) {
+	public function initialize(Server $server) {
+		$this->server = $server;
+		$server->on('propFind', [$this, 'propFind'], 90);
+	}
 
+	/**
+	 * PropFind
+	 *
+	 * This method handler is invoked before any after properties for a
+	 * resource are fetched. This allows us to add in any CalDAV specific
+	 * properties.
+	 *
+	 * @param DAV\PropFind $propFind
+	 * @param DAV\INode $node
+	 * @return void
+	 */
+	public function propFind(DAV\PropFind $propFind, DAV\INode $node) {
+		if ($node instanceof IPrincipal) {
+			$principalUrl = $node->getPrincipalUrl();
+			$propFind->handle('{' . self::NS_CALDAV . '}calendar-home-set', function () use ($principalUrl) {
+				$calendarHomes = [];
+				// Make sure the dav apps caldav endpoint is at the first place
+				$calendarHomePath = $this->getCalendarHomeForPrincipal($principalUrl);
+				if ($calendarHomePath !== null) {
+					$calendarHomes[] = $calendarHomePath;
+				}
+				foreach ($this->server->getPlugins() as $plugin) {
+					if ($plugin instanceof ICalendarHomePlugin && $plugin !== $this) {
+						$calendarHomePath = $plugin->getCalendarHomeForPrincipal($principalUrl);
+						if ($calendarHomePath !== null) {
+							$calendarHomes[] = $calendarHomePath;
+						}
+					}
+				}
+				return new LocalHref($calendarHomes);
+			});
+		}
+	}
+
+	/**
+	 * Add the Nextcloud default calendar home
+	 *
+	 * @inheritdoc
+	 */
+	public function getCalendarHomeForPrincipal($principalUrl) {
 		if (strrpos($principalUrl, 'principals/users', -strlen($principalUrl)) !== false) {
 			list(, $principalId) = \Sabre\Uri\split($principalUrl);
 			return self::CALENDAR_ROOT .'/' . $principalId;
 		}
-
-		return;
+		return null;
 	}
 
 }

apps/dav/lib/Server.php

@@ -135,6 +135,7 @@ public function __construct(IRequest $request, $baseUri) {
 		$this->server->addPlugin($acl);
 
 		// calendar plugins
+		$this->server->addPlugin(new \Sabre\CalDAV\Plugin());
 		$this->server->addPlugin(new \OCA\DAV\CalDAV\Plugin());
 		$this->server->addPlugin(new \Sabre\CalDAV\ICSExportPlugin());
 		$this->server->addPlugin(new \OCA\DAV\CalDAV\Schedule\Plugin());