Add migration step

apps/dav/appinfo/database.xml

@@ -275,7 +275,7 @@ CREATE TABLE calendarobjects (
 		<field>
 			<comments>0 - public, 1 - private, 2 - confidential</comments>
 			<name>classification</name>
-			<type>int</type>
+			<type>integer</type>
 			<default>0</default>
 		</field>
 		<index>

apps/dav/appinfo/update.php

@@ -24,3 +24,4 @@ use OCA\DAV\AppInfo\Application;
 
 $app = new Application();
 $app->generateBirthdays();
+$app->migrateClassification();

apps/dav/lib/AppInfo/Application.php

@@ -31,10 +31,12 @@ use OCA\DAV\CardDAV\SyncService;
 use OCA\DAV\Connector\Sabre\Principal;
 use OCA\DAV\DAV\GroupPrincipalBackend;
 use OCA\DAV\HookManager;
+use OCA\DAV\Migration\Classification;
 use \OCP\AppFramework\App;
 use OCP\AppFramework\IAppContainer;
 use OCP\Contacts\IManager;
 use OCP\IUser;
+use Sabre\VObject\Reader;
 use Symfony\Component\EventDispatcher\GenericEvent;
 
 class Application extends App {
@@ -168,4 +170,20 @@ class Application extends App {
 			$this->getContainer()->getServer()->getLogger()->logException($ex);
 		}
 	}
+
+	public function migrateClassification() {
+		try {
+			/** @var CalDavBackend $calDavBackend */
+			$calDavBackend = $this->getContainer()->query('CalDavBackend');
+			$migration = new Classification($calDavBackend);
+			$userManager = $this->getContainer()->getServer()->getUserManager();
+
+			$userManager->callForAllUsers(function($user) use($migration) {
+				/** @var IUser $user */
+				$migration->runForUser($user);
+			});
+		} catch (\Exception $ex) {
+			$this->getContainer()->getServer()->getLogger()->logException($ex);
+		}
+	}
 }

apps/dav/lib/migration/classification.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace OCA\DAV\Migration;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCP\IUser;
+
+class Classification {
+
+	/**
+	 * Classification constructor.
+	 *
+	 * @param CalDavBackend $calDavBackend
+	 */
+	public function __construct(CalDavBackend $calDavBackend) {
+		$this->calDavBackend = $calDavBackend;
+	}
+
+	/**
+	 * @param IUser $user
+	 */
+	public function runForUser($user) {
+		$principal = 'principals/users/' . $user->getUID();
+		$calendars = $this->calDavBackend->getCalendarsForUser($principal);
+		foreach ($calendars as $calendar) {
+			$objects = $this->calDavBackend->getCalendarObjects($calendar['id']);
+			foreach ($objects as $object) {
+				$calObject = $this->calDavBackend->getCalendarObject($calendar['id'], $object['id']);
+				$classification = $this->extractClassification($calObject['calendardata']);
+				$this->calDavBackend->setClassification($object['id'], $classification);
+			}
+		}
+	}
+
+	/**
+	 * @param $calObject
+	 */
+	protected function extractClassification($calendarData) {
+		return $this->calDavBackend->getDenormalizedData($calendarData)['classification'];
+	}
+}