Investigating Caldav for Different Clients

1 Initial Problem

An appointment in ILIAS is transferred i.e. to google calendar, apple calendar, outlook calendar, or android calendar client.

There are different actions for appointments in ILIAS:

• Creating appointments,
• updating appointments and
• deleting appointments. 

2 Way Forward

• CalDav might improve the situation, but it cannot replace iCal.
• ILIAS must talk iCal and CalDAV, because 
  • google calendar does not speak CalDAV and presumably never will.
  • outlook calendar requires a plugin to speak CalDAV
  • Apple and android will work splendidly, though. 
• Upon including a calendar one has to select CalDAV or iCal.
• CalDav always needs an authenticated users (LDAP, DB, but not Shiboleth). Appointments for authenticated users can be updated. 

3 Workshops

A total of three feature workshops are conducted: 

• Particpants outline which calendar clients are used in their organisations. 
• Participants explain their calendar use cases and requirements. 
• Participants are asked to prepare test data on the test platform (see below) and check, whether CalDAV-library „SabreDAV“ meets their requirements.
• The results are prioritized and feature requests are prepared. 

4 Test Installation and Tests 

1. Provide Test Platform 

   We install an ILIAS including with the libraries of CalDAV and implement the following 

   • HTTP-Basic-authentication supporting ILIAS- and LDAP-accounts 
   • Read access to appointnemnts per CalDAV exported appointments 
   • Checking write access per appointment and updates of appointments by calendar client 
   • Synchronising all calendar apointments into one single ILIAS calendar. 

2. Test Use Cases for Different Clients

   • We should create all kinds of appointments: individual appointments, recurring appointments, with reading permission, reading and writing permissions, updating appointments and "deleting" appointments. 
   • We should gather all kind of clients: google calendar, android calendar, apple calendar, outlook calendar and nextcloud calendar. 
   • We test the use cases with different devices. 

3. Prepare Feature Requests 

5 Contact

• Author of the Request: Tödt, Alexandra [atoedt]
• Maintainer: Meyer, Stefan [smeyer]
• Implementation of the feature is done by: {The maintainer must add the name of the implementing developer.}

6 Discussion

Strassner, Denis [dstrassner], 24. NOV 2023: See https://github.com/ILIAS-eLearning/ILIAS/pull/6651 and https://sabre.io/dav/