<?php namespace Sabre\CalDAV\Backend; /** * WebDAV-sync support for CalDAV backends. * * In order for backends to advertise support for WebDAV-sync, this interface * must be implemented. * * Implementing this can result in a significant reduction of bandwidth and CPU * time. * * For this to work, you _must_ return a {http://sabredav.org/ns}sync-token * property from getCalendarsFromUser. * * @copyright Copyright (C) fruux GmbH (https://fruux.com/) * @author Evert Pot (http://evertpot.com/) * @license http://sabre.io/license/ Modified BSD License */ interface SyncSupport extends BackendInterface { /** * The getChanges method returns all the changes that have happened, since * the specified syncToken in the specified calendar. * * This function should return an array, such as the following: * * [ * 'syncToken' => 'The current synctoken', * 'added' => [ * 'new.txt', * ], * 'modified' => [ * 'modified.txt', * ], * 'deleted' => [ * 'foo.php.bak', * 'old.txt' * ] * ); * * The returned syncToken property should reflect the *current* syncToken * of the calendar, as reported in the {http://sabredav.org/ns}sync-token * property This is * needed here too, to ensure the operation is atomic. * * If the $syncToken argument is specified as null, this is an initial * sync, and all members should be reported. * * The modified property is an array of nodenames that have changed since * the last token. * * The deleted property is an array with nodenames, that have been deleted * from collection. * * The $syncLevel argument is basically the 'depth' of the report. If it's * 1, you only have to report changes that happened only directly in * immediate descendants. If it's 2, it should also include changes from * the nodes below the child collections. (grandchildren) * * The $limit argument allows a client to specify how many results should * be returned at most. If the limit is not specified, it should be treated * as infinite. * * If the limit (infinite or not) is higher than you're willing to return, * you should throw a Sabre\DAV\Exception\TooMuchMatches() exception. * * If the syncToken is expired (due to data cleanup) or unknown, you must * return null. * * The limit is 'suggestive'. You are free to ignore it. * * @param string $calendarId * @param string $syncToken * @param int $syncLevel * @param int $limit * @return array */ function getChangesForCalendar($calendarId, $syncToken, $syncLevel, $limit = null); }