Calendar events are disappearing randomly

[Jarosch]

Hi.
Please see this link here. There I've shared a video which is showing the behaviour of the plugin while scrolling through the months. Events are disappering and appearing again when scrolling through the months up and down.

Link to video: https://1drv.ms/v/s!Ao83UV5As0xGgZQIWL_ch-0sLVFSZA?e=58o58m

Do you have an idea what is the reason for that?
You can just check it by yourself at following adress: http://kgv-bellingholz.de/events

[wernerjoss]

Hm, I can't reproduce this with my Calendar - I can switch forth and back without events disappear.
might be a browser cache issue ?
btw., your calendar link is dead (404)

[Jarosch]

Hi,
I updated to fullcalendar V5, but it hasn't solved the issue. It seems that the problem comes up, when there are more than one ICS files. I've updated my host. Now you should be able to access the "Events" page where you will see what is happening when you roll through the months.

[wernerjoss]

well, I can see the disappearing (and re-appearing) events in your calendar now.
as said, this does not happen with my calendar, which has 3 ics files - so more than 1 ics file is not the problem.
I guess the issue is related to some javascript/jquery interference, maybe triggered by the theme.
you could try to change your jquery version to jquery-3 (currently: jquery-2).
if that does not help, what happens if you switch to a better supported theme, e.g. quark ?
(currently, you are using twenty-fifteen, which is only a bad and incomplete port of an old WP theme).
additionally: how did you update to fc5 ?
just by copying the fc5 files into the fc4 folders ?

[Jarosch]

Hi,
I've updated the jquery version to v3. No changes.
I've also tried the "Quark" theme. Same behaviour. So, it's not theme related.

Yeah, I've just updated the fullcalendar by using the npm-tool and replaced the file content in the folders by the new files.

[wernerjoss]

well, then, I guess there is not much more left that I can propose, except this:
set verbose to true in calendar.js, line 17.
then you will get a lot of output in javascript console, including detailed info about calendars beeing loaded,
and events lists.
additionally, you can disable grav's cache for your calendar page, see the docs

[Jarosch]

Hi again.
Well, after changing "verbose" to true, I've figured out that in case that the events are missing, the "allevents" variable is not filled with events. Index is 0 and do_callback is false. After toggling the month forward and backward, the allevents array is filled up again and index is 1 and do_callback is true.
The events array is filled with the same amount of values at each time.

[wernerjoss]

strange - I cannot reproduce this: for me, allevents and events variables are always populated as expected
(events holds one calendar, allevents all calendars), index is 2 and do_callback is true.
so, ATM, I'm out of ideas what is causing this problem.

[Jarosch]

Hi,
it's curious. In general I've figured that in some cases, the script starts parsing not the same file as before. And when this happens, the allevents var is not complete, what leads into missing events in the calendar.
I have created two logs for you for the month "November" in 2022. There I expect the event "Allerheiligen" in the 1st of November.

Check here for a quick diff: https://quickdiff.net/?unique_id=7F4100C8-C163-BCDF-628B-7256873C73CF
The left window shows the log with the missing "Allerheiligen" event. The right window shows the log with the "Allerheiligen" event shown in the calendar.

kgv-bellingholz.de-november_22-missing.log
kgv-bellingholz.de-november_22-complete.log

[wernerjoss]

Your calendar ICs Files seem top be in your Page folder (which ist a valid Option) ? Can your Check what Happens when they are in user/data/calendars? -- Diese Nachricht wurde von meinem Android-Gerät mit K-9 Mail gesendet. Am 25. Juli 2022 08:31:59 MESZ schrieb Jarosch ***@***.***>:

…

Hi, it's curious. In general I've figured that in some cases, the script starts parsing not the same file as before. And when this happens, the allevents var is not complete, what leads into missing events in the calendar. I have created two logs for you for the month "November" in 2022. There I expect the event "Allerheiligen" in the 1st of November. Check here for a quick diff: https://quickdiff.net/?unique_id=7F4100C8-C163-BCDF-628B-7256873C73CF [kgv-bellingholz.de-november_22-missing.log](https://github.com/wernerjoss/grav-plugin-fullcalendar/files/9178559/kgv-bellingholz.de-november_22-missing.log) [kgv-bellingholz.de-november_22-complete.log](https://github.com/wernerjoss/grav-plugin-fullcalendar/files/9178560/kgv-bellingholz.de-november_22-complete.log) -- Reply to this email directly or view it on GitHub: #52 (comment) You are receiving this because you commented. Message ID: ***@***.***>

[Jarosch]

Yes, this solved the issue.

So, probably there‘s something wrong in parsing the files doing it the other way.

Thanks for your support!

[wernerjoss]

ok, that's fine and also explains why I could not reproduce this 😄 .
in fact, I never used the feature 'calendar files in page folder' in a production environment, just developed it upon request, tested and found no problems (maybe just overlooked).
I'll then dig a bit deeper into this and try to solve it, of course, but that will take awhile as I'm currently busy with other things.
so, for the time being, I'll add some hint to the docs and leave this issue open.
thanks for reporting !