Edits to calendar events are not correctly reflected in Google Calendar

[jacksojourn]

Description

Rock calendar events changed aren't reflected on Google calendar via subscription URL.

Actual Behavior

When an event is edited on the Rock (e.g. date or time is changed), Google calendar continues to show the original event with no changes (even after 24 hours).

Expected Behavior

When an event is edited on the Rock (e.g. date or time is changed), that change would be reflected on Google calendar later, automatically.

Steps to Reproduce

1. Create any Rock event
2. Export the calendar feed
3. In Google Calendar, subscribe to the calendar feed URL
4. In Rock, change the event date or time
5. Wait 24+ hours for Google calendar to update
6. Change should be reflected on Google calendar but is not

Note: In Rock v 14.x, it was a known limitation that deleted events would persist on Google calendar conversation here. However, edits would be still synced to Google calendar. Now no edits are syncing at all.

If you force Google to ignore its cached version by appending, e.g., "#v2" to the end of the calendar URL, then it syncs properly. But this is the only way to force it to update.

NOTE: it is not possible to test this on the demo site due to the site resetting every day. Need >24h to test.

Issue Confirmation

• Perform a search on the Github Issues to see if your bug or enhancement is already reported.
• Try to reproduce the problem on a fresh install or on the demo site.

Rock Version

1.15.1.1

Client Culture Setting

en-US

[MrUpsideDown]

@jacksojourn - Sorry this is still causing you some headaches. You mentioned that the workaround of appending a randomized fragment to the calendar URL ("#v2", etc.) will force a refresh, which indicates to me that this continues to be a problem with the Google cache rather than the behavior of Rock itself. I've seen a number of suggestions from others experiencing the same problem in other applications that the Google cache period may be longer than 24 hours in some circumstances, but there seems to be no guaranteed time period in which the refresh will definitely happen.
If the refresh is not happening at all other than when forced, it might be worth verifying that Google sync is enabled for your specific calendar feed. Strangely, I don't think this is switched on by default when you add a new feed but you can check it here:
https://calendar.google.com/calendar/u/0/syncselect

Aside from that, I'm not sure that there is anything we can do from the Rock side to improve this situation - if you have any suggestions or additional information, please let me know.

[MrUpsideDown]

@jacksojourn - To clarify this further, does this issue affect edited events and newly-added events? Or do newly-added events show up within the 24-hour refresh period but edited events do not?

[jacksojourn]

@MrUpsideDown Hey, thanks for your comments.

New events are added correctly, but once they are synced to Google Calendar the first time, they are locked in forever. No additional changes from the Rock are ever reflected.

My Google sync settings were off, but turning them didn't change anything for me.

I'm gonna post in some Google forums where I got some help before and see if they have any ideas. Maybe we can confirm that this issue is on Google's end.

[jonedmiston]

@jacksojourn I think we have a likely fix. There is a sequence number that we may need to increment as events change. Wanted to make you aware of this before you spent too much time posting.

[jacksojourn]

@jonedmiston Thanks! I posted already, so I'll let you know I get any useful information.

[MrUpsideDown]

@jacksojourn - As @jonedmiston previously mentioned, we have added a sequence number to the events in the iCalendar output to fix this issue. The sequence number is calculated from when the event was last modified in Rock, which informs Google Calendar when an event has been superseded and should be replaced. Thanks for your helpful feedback and your patience on this, it is much appreciated.

[jacksojourn]

@MrUpsideDown ❤️