Support tagging events hosted on external (CalDAV) calendars.

[RokeJulianLockhart]

Checklist

• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
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• This issue contains only one feature request.
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Feature description

A one-to-many correspondence, possible to combine and exclude when filtering.

Why do you want this feature?

To organize them in a manner which embeds into the iCS file / calendar event.

Additional information

FossifyOrg/General-Discussion#127 (comment)

[Aga-C]

Isn't event types enough? You can already filter by them.

[RokeJulianLockhart]

#162 (comment)

@Aga-C, I don't see any option to use such a feature using https://wim.nl.tab.digital/apps/calendar/p/dMyP8x8mNB2rM4cD or https://calendar.google.com/calendar/u/0?cid=cm9rZWp1bGlhbmxvY2toYXJ0QGdtYWlsLmNvbQ via https://github.com/FossifyOrg/Calendar/releases/download/1.0.2/calendar-3-foss-release.apk from https://play.google.com/store/apps/details?id=org.fossify.calendar&pcampaignid=web_share.

[Aga-C]

Event types are supported only for local calendar. It's currently not supported for CalDAV synchronized calendars, because the app treats synchronized calendar as an event type itself. We'd need to add distinction between calendars and event types, what may even be a bit related to #92.

[RokeJulianLockhart]

#162 (comment)

@Aga-C, glad for the context, although I fail to see how that correlates it with #162 (comment) specifically. Regardless, should this issue be renamed to reflect the specific absence of the feature on all except local calendars consequently? After all, it seems like the feature exists in that specific context, so the scope of the issue should probably be reduced. I'll do so unless you disagree.

[Aga-C]

I was thinking about that once again, and I'm just curious about the example you've sent from NextCloud. By tagging events, you mean that those events are tagged as "Everything"?

If so, this is the same as event type in Fossify Calendar. What's more, you can already change them. The only requirement is that you need to have them defined on your CalDAV provider and synchronized in the app, as we can't create new ones due to no Internet access.

[RokeJulianLockhart]

#162 (comment)

@Aga-C, I believe you're referring to something else, for “Everything” is the name of the calendar itself. What I'm describing is what https://github.com/nextcloud/documentation/blob/9f188a307f92d634551cde6129d958b21b4f6fdb/user_manual/groupware/calendar.rst#add-attachments-to-events depicts (although unfortunately the documentation lacks explicit description of the feature, per nextcloud/documentation#789 (comment)):

However, it's obviously tags.