Trilium: Investigate support for CalDAV

[zadam]

• calendar
• notes / tasks

This might elegantly "solve" missing Android/iOS client.

[improvethings]

Consider integration with NextCloud. They do CalDAV, ACLs, and calendaring quite well.

[zadam]

Hello, people mentioned NextCloud before, but I have trouble understanding what exactly the mean by integrating with NextCloud. Do you mean that synchronization should use NextCloud as a server (in a similar way as Dropbox might be used)? Or something else?

[siliconninja]

Joplin uses WebDAV to connect to Nextcloud and sync note files in Nextcloud. (CalDAV is mainly used for storing calendar events, notes and reminders, and WebDAV is mainly used for files. My opinion: using CalDAV for sync seems like an interesting solution, as long as if you have a huge note file, it doesn't slow down downloading and uploading changes.) That way, you don't have to run a separate server application other than Nextcloud. I mean that sync should use Nextcloud as a server to host the files on, similar to Dropbox. Personally, I would like that feature incorporated. I'm not sure if that's what @improvethings means though.

[zadam]

Thanks for explanation.

Synchronization through WebDAV (and other file based solutions) is possible, but difficult for few reasons - Trilium document doesn't map well onto filesystem - it's actually not simple tree structure, but an extension which allows hard linking any note into multiple places in the tree (see cloning). We would also have to store meta data along side the files to describe e.g. links and relations between notes. What would be probably problematic is the ordering of changes - normal sync operations need to keep exact order to stay consistent at all times (e.g. you can't create the link to the note before creating the note itself). There are probably other issues I don't see right now. Of course all these issues are solvable (typically you create more metadata to e.g. define the sync order), but it can get pretty difficult. Having native sync server simplifies this a lot.

What I meant by the CalDAV support when I was creating this ticket was something quite different - my original idea was to implement CalDAV server support on Trilium so mobile calendaring / TODO clients could connect to it and read/save events and notes there. This would work probably only for a subset of notes since there would be some restrictions.

[chris-morgan]

Something else worth contemplating in this space is JMAP. Its calendar spec is still draft, however. See https://fastmail.blog/2018/12/27/jmap-is-on-the-home-straight/ for some context on current events.