DAViCal

CalDAV specification has been under development for a few years now, and at the same time we have seen increasing pressure from people and organisations in the open source world to provide a solution to their shared calendaring problems.

In evaluating the possibilities for shared calendaring, there are a number of possible approaches, but we have elected to follow the path of implementing CalDAV because we believe it is a good specification and that it will in due course gain client implementations and provide the richest user experience through those client implementations.

Goals

CalDAV is a client-server protocol specific to managing and reporting on collections of calendar resources.

As such, our intentions in developing this application are as follows:

Simplicity of Prerequisites

We have chosen to write this in PHP because we believe that PHP is a widely available web scripting language.

We have chosen to use the Apache web server because it is also widely available. This is not necessarily a requirement, but no testing has been undertaken in other PHP environments to date.

We have chosen to use the PostgreSQL database, because it is a free, open-source database, which operates on a very wide set of operating environments, and which is fully ACID compliant.

Simplicity of Setup

For the greatest ease use you should consider installing RSCDS on the Debian GNU/Linux distribution from the readily available, signed packages.
We expect to increase the level of automation and simplicity for the Debian target release in particular, although other distributions might also become easier at the same time. We do expect slightly greater installation complexity in the first few releases as we come to understand the particular problems people experience.

Simplicity of Operation

In general RSCDS should not need significant maintenance to keep it operating.

Administrative functionality will be kept as simple as possible, within the target of supporting organisations of up to several hundred staff.
This is called a Store rather than a Server because the server-side smarts are intended to be minimised to support CalDAV only in a manner sufficient to inter-operate with clients, and with the focus primarily on the storage of calendar resources.

Web-based Administration

General administration of the system should be through a web-based application.

Calendars will not be made available in a web-based view in initial releases. It is unlikely that calendars will ever be maintainable through a web-based client, although the server should support the use of web-based client software which works using the CalDAV protocol.

What is new in this release:

• Fix bug in scheduling on POST request.
• Fix permissions on user create via external auth.
• Add a default min_age for external binds.
• Prevent external binds from being created/updated if curl is missing.
• Add check to setup page to test whether curl is installed.
• Allow for silly programs that send content-type XML with a GET request.
• Support use of HTTP_AUTHORIZATION in addition to AUTHORIZATION cgi.
• Handle VCARD adr/tel/email which have multiple types.
• Set the default URL to the default calendar name rather than /home/
• Enable the file upload for addressbook collections.
• Handle addressbook import along with calendar import.
• Write UID and REV property n VCARD if they are missing.
• Update translations to current transifex translations.

What is new in version 0.9.9.4:

• Refactor PUT functions to set modified/created dates more correctly.
• add et_EE to support locales
• Fix errors in po files pointed out by Transifex uploading.
• A new AtomFeed class for building an Atom feed.
• Switch to creating an atom feed, which is a better feed standard.
• A new URL to provide an RSS feed of a calendar's changes.
• Refactored RRule to add support for initialisation from a vProperty.
• Remove all reference to PgQuery
• Extensive refactoring of principal-edit, plus support for creating tickets.
• Add support for writing scheduling resources on PUT.
• Improve support for handling floating time.
• Add cil for internal issue tracking.
• Cut access with invalid/expired tickets out immediately.
• Handle empty PROPFIND, don't blow up on invalid XML.
• /.well-known/now returns a 301 redirect, per spec.
• Use text/vcard for content type in advance of ratification of spec.
• Properly handle addressbooks in multiget.
• Hide authorization headers in logging.
• Update sync-collection REPORT to match -04 of draft.
• Replace index.php with caldav.php when we find it in our path.
• Be pedantic about checking user is active before we let them in.
• Specify the SRV record examples with leading _ as they should be.
• Fix SQL for group handling from Michael Braun.
• Add principal-collection-set to standard responses for DAVResource.
• Correct typo in POST handling.
• Also update displayname if fullname is changed.
• remove old screenshots
• updated iPhone client configuration with new screenshots
• Handle stuff like DTSTART;TZID=America/New_York:20101119T231307
• Script to refresh calendar_alarms with next instance time.
• Don't let auth functions create duplicate home calendars.
• Patch for caldav sync from Pierre-Arnaud Poudret.
• Add ACL to the supported methods.
• Change regression runner to look for sample data with tests.
• Correct version number typo.
• Always grant 'DAV::read' privilege from principal to group members.
• Use expanded time specifiers in format since %Y doesn't work on Windows.
• Support recursive REPORT query if configured to allow it.
• Add a new WritableCollection object which we will use for PUT.
• Use text/vcard rather than older text/x-vcard.
• Support event properties in changed part of sync-response.
• Rename variable to work around Pg 9.0 reserved name.
• Switch from regular expression which may not work in old/odd PHP.
• Support getlastmodified property in REPORT requests.
• Fix typo in iTIP CANCEL handling.
• Turn on calendar-auto-schedule header if $c->enable_auto_schedule
• Add various additional checks into /setup.php
• Add knowledge of desired parallel AWL version to setup.
• Fix various minor CardDAV bugs.
• Omit the for event outside the time range - when expanded.
• Fix privilege_to_bits function to set 'all' correctly & work with recent postgres
• Don't supply freebusy for 0-duration events.
• Another regression test for free/busy catching many events.
• Add an event with a thoroughly bogus tzid to ensure we cope.
• Check for some supported stuff very early so we can show it is missing.
• Better display of bindings.
• Add postgreSQL 9.0 as a possibility.
• Fix warning when using basic authentication fallback.
• Fix handling of iCalendar durations containing negative elements.
• Handle events which don't have either DTEND *orDURATION.
• Rewrite __construct() method of RepeatRuleDateTimeZone to be more robust.

What is new in version 0.9.9.3:

• This release mainly includes bugfixes for the CardDAV support that landed in 0.9.9.2, making it more reliable and adding some backward-compatibility options for the Inverse plugin for Lightning.

What is new in version 0.9.9.2:

• This is a significant new release, adding initial support for the draft vCard Extensions to WebDAV (CardDAV).
• Other changes update the WebDAV Sync support to draft version -03 and add support for handling /.well-known/caldav and /.well-known/carddav URLs per RFC5785.
• The release also includes many bugfixes, updated translations, and better resiliency for clients which don't adhere strictly to the RFC, such as by not supplying a Content-type when they PUT a new or changed resource.
• UTF-8 handling is also improved.

What is new in version 0.9.7.2:

• Some workarounds were added for problems with iPhone OS 3.1.
• Some new features were added to support easier configuration with iPhone/iCal clients.
• All occurrences of deprecated call time pass by reference that were highlighted by PHP 5.3 warnings were removed.
• Problems caused by failure to encode URLs in some situations were comprehensively fixed.

What is new in version 0.9.7.1:

• This release provides a facility for logging INSERT / UPDATE / DELETE actions on CalDAV resources and conducts email-based lookups for free/busy information case insensitively, if possible.
• Several bugs were also fixed, including correctly populating the user drop-down when associating users to a group and ensuring that %XX encoded characters in incoming URLs are decoded before processing.
• This release also includes an updated French translation.

What is new in version 0.9.7:

• Add debug logging of response/request and related headers.
• Various fixes for compatibility with iPhone v3 OS.
• Align freebusy.php parameter handling with proposed standard.
• Allow free/busy permission to grant access to obfuscated calendar.
• Basic implementation of calendar proxy.
• Switch to RRULE functions for more accurate overlap calculation.
• Added support for publicly_readable attribute of collection when accessing a /public.php/user/collection/ path.
• Allow configuration of site wide user default values.

What is new in version 0.9.6.2:

• Fix creation of database when template1 has pl/pgsql installed.
• Improvements to regression testing.
• Switch to use iCalComponent object rather than iCalendar, in many cases.
• Calculate DTEND when it is not set according to RFC2445.
• Much improved XML namespace handling.
• Configuration setting to control visibility of appointments for organizer/attendee, even if they are PRIVATE and not in their own calendar.
• Updated French translation
• Add facility to delete collections through the management interface.

Requirements:

• PHP
• PostgreSQL