<?php
namespace Sabre\CalDAV\Backend;
/**
* Adds support for sharing features to a CalDAV server.
*
* Note: This feature is experimental, and may change in between different
* SabreDAV versions.
*
* Early warning: Currently SabreDAV provides no implementation for this. This
* is, because in it's current state there is no elegant way to do this.
* The problem lies in the fact that a real CalDAV server with sharing support
* would first need email support (with invite notifications), and really also
* a browser-frontend that allows people to accept or reject these shares.
*
* In addition, the CalDAV backends are currently kept as independent as
* possible, and should not be aware of principals, email addresses or
* accounts.
*
* Adding an implementation for Sharing to standard-sabredav would contradict
* these goals, so for this reason this is currently not implemented, although
* it may very well in the future; but probably not before SabreDAV 2.0.
*
* The interface works however, so if you implement all this, and do it
* correctly sharing _will_ work. It's not particularly easy, and I _urge you_
* to make yourself acquainted with the following document first:
*
* https://trac.calendarserver.org/browser/CalendarServer/trunk/doc/Extensions/caldav-sharing.txt
*
* An overview
* ===========
*
* Implementing this interface will allow a user to share his or her calendars
* to other users. Effectively, when a calendar is shared the calendar will
* show up in both the Sharer's and Sharee's calendar-home root.
* This interface adds a few methods that ensure that this happens, and there
* are also a number of new requirements in the base-class you must now follow.
*
*
* How it works
* ============
*
* When a user shares a calendar, the updateShares() method will be called with
* a list of sharees that are now added, and a list of sharees that have been
* removed.
* Removal is instant, but when a sharee is added the sharee first gets a
* chance to accept or reject the invitation for a share.
*
* After a share is accepted, the calendar will be returned from
* getUserCalendars for both the sharer, and the sharee.
*
* If the sharee deletes the calendar, only their share gets deleted. When the
* owner deletes a calendar, it will be removed for everybody.
*
*
* Notifications
* =============
*
* During all these sharing operations, a lot of notifications are sent back
* and forward.
*
* Whenever the list of sharees for a calendar has been changed (they have been
* added, removed or modified) all sharees should get a notification for this
* change.
* This notification is always represented by:
*
* Sabre\CalDAV\Notifications\Notification\Invite
*
* In the case of an invite, the sharee may reply with an 'accept' or
* 'decline'. These are always represented by:
*
* Sabre\CalDAV\Notifications\Notification\Invite
*
*
* Calendar access by sharees
* ==========================
*
* As mentioned earlier, shared calendars must now also be returned for
* getCalendarsForUser for sharees. A few things change though.
*
* The following properties must be specified:
*
* 1. {http://calendarserver.org/ns/}shared-url
*
* This property MUST contain the url to the original calendar, that is.. the
* path to the calendar from the owner.
*
* 2. {http://sabredav.org/ns}owner-principal
*
* This is a url to to the principal who is sharing the calendar.
*
* 3. {http://sabredav.org/ns}read-only
*
* This should be either 0 or 1, depending on if the user has read-only or
* read-write access to the calendar.
*
* Only when this is done, the calendar will correctly be marked as a calendar
* that's shared to him, thus allowing clients to display the correct interface
* and ACL enforcement.
*
* If a sharee deletes their calendar, only their instance of the calendar
* should be deleted, the original should still exists.
* Pretty much any 'dead' WebDAV properties on these shared calendars should be
* specific to a user. This means that if the displayname is changed by a
* sharee, the original is not affected. This is also true for:
* * The description
* * The color
* * The order
* * And any other dead properties.
*
* Properties like a ctag should not be different for multiple instances of the
* calendar.
*
* Lastly, objects *within* calendars should also have user-specific data. The
* two things that are user-specific are:
* * VALARM objects
* * The TRANSP property
*
* This _also_ implies that if a VALARM is deleted by a sharee for some event,
* this has no effect on the original VALARM.
*
* Understandably, the this last requirement is one of the hardest.
* Realisticly, I can see people ignoring this part of the spec, but that could
* cause a different set of issues.
*
*
* Publishing
* ==========
*
* When a user publishes a url, the server should generate a 'publish url'.
* This is a read-only url, anybody can use to consume the calendar feed.
*
* Calendars are in one of two states:
* * published
* * unpublished
*
* If a calendar is published, the following property should be returned
* for each calendar in getCalendarsForPrincipal.
*
* {http://calendarserver.org/ns/}publish-url
*
* This element should contain a {DAV:}href element, which points to the
* public url that does not require authentication. Unlike every other href,
* this url must be absolute.
*
* Ideally, the following property is always returned
*
* {http://calendarserver.org/ns/}pre-publish-url
*
* This property should contain the url that the calendar _would_ have, if it
* were to be published. iCal uses this to display the url, before the user
* will actually publish it.
*
*
* Selectively disabling publish or share feature
* ==============================================
*
* If Sabre\CalDAV\Property\AllowedSharingModes is returned from
* getCalendarsByUser, this allows the server to specify whether either sharing,
* or publishing is supported.
*
* This allows a client to determine in advance which features are available,
* and update the interface appropriately. If this property is not returned by
* the backend, the SharingPlugin automatically injects it and assumes both
* features are available.
*
* @copyright Copyright (C) 2007-2014 fruux GmbH (https://fruux.com/).
* @author Evert Pot (http://evertpot.com/)
* @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
*/
interface SharingSupport extends NotificationSupport {
/**
* Updates the list of shares.
*
* The first array is a list of people that are to be added to the
* calendar.
*
* Every element in the add array has the following properties:
* * href - A url. Usually a mailto: address
* * commonName - Usually a first and last name, or false
* * summary - A description of the share, can also be false
* * readOnly - A boolean value
*
* Every element in the remove array is just the address string.
*
* Note that if the calendar is currently marked as 'not shared' by and
* this method is called, the calendar should be 'upgraded' to a shared
* calendar.
*
* @param mixed $calendarId
* @param array $add
* @param array $remove
* @return void
*/
function updateShares($calendarId, array $add, array $remove);
/**
* Returns the list of people whom this calendar is shared with.
*
* Every element in this array should have the following properties:
* * href - Often a mailto: address
* * commonName - Optional, for example a first + last name
* * status - See the Sabre\CalDAV\SharingPlugin::STATUS_ constants.
* * readOnly - boolean
* * summary - Optional, a description for the share
*
* This method may be called by either the original instance of the
* calendar, as well as the shared instances. In the case of the shared
* instances, it is perfectly acceptable to return an empty array in case
* there are privacy concerns.
*
* @param mixed $calendarId
* @return array
*/
function getShares($calendarId);
/**
* This method is called when a user replied to a request to share.
*
* If the user chose to accept the share, this method should return the
* newly created calendar url.
*
* @param string href The sharee who is replying (often a mailto: address)
* @param int status One of the SharingPlugin::STATUS_* constants
* @param string $calendarUri The url to the calendar thats being shared
* @param string $inReplyTo The unique id this message is a response to
* @param string $summary A description of the reply
* @return null|string
*/
function shareReply($href, $status, $calendarUri, $inReplyTo, $summary = null);
/**
* Publishes a calendar
*
* @param mixed $calendarId
* @param bool $value
* @return void
*/
function setPublishStatus($calendarId, $value);
}
