Bug 401773

Summary: Non-standard iCal fields cannot be interpreted by third-party applications: Do not use them non-standard iCal fields
Product: [Applications] zanshin Reporter: Erik Quaeghebeur <bugs.kde.org>
Component: generalAssignee: Kevin Ottens <ervin>
Status: REPORTED ---    
Severity: normal CC: mbensi, openmail+kde
Priority: NOR    
Version First Reported In: 0.5.0   
Target Milestone: already done   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Custom akonadi date field used for recurring tasks

Description Erik Quaeghebeur 2018-12-05 15:30:11 UTC 
Zanshin, probably via the underlying kcal library, sometimes generates ics files with non-standard fields. For example,

X-KDE-LIBKCAL-DTRECURRENCE

appears when a recurring task is marked as done. This is obviously not a field that third-party applications will be able to interpret, making syncing useless when using this feature. However, syncing and using third-party applications is important in the context of tasks.

So therefore an implementation request: do not use such non-standard field, please! Kontact/Zanshin do not and will not in the foreseeable future have the market share to force third parties to even consider its non-standard fields and they make using Kontact and Zanshin inconvenient (one needs to learn how to avoid certain features). This will obviously limit Zanshin functionality somewhat, but other applications have managed to deal with this as well.

Obviously, it can be argued that Zanshin is a KDE application and it should not be restricted by such interoperability considerations. I do hope such acceptance of lock-in is not present.
Comment 1 Schlaefer 2022-06-20 11:41:48 UTC 
Created attachment 149950 [details]
Custom akonadi date field used for recurring tasks

Same issue here. iCal fields for the task:

DUE;VALUE=DATE:20220501
DTSTART;VALUE=DATE:20220501
...
X-KDE-LIBKCAL-DTRECURRENCE;VALUE=DATE-TIME;TZID=Europe/Berlin:
 20220626T000000

--- 

Since the custom field is used for recurring tasks these don't sync properly to non-akonadi devices and applications. 

The iCal backend should use the standard iCal date field instead of X-KDE... to be compatible with other clients.