Content flickers when calendar component is reinitialized via useState

[Azaryan-A]

Reduced Test Case

https://stackblitz.com/edit/github-urj6el-oghacn?file=src%2FDemoApp.jsx

Do you understand that if a reduced test case is not provided, we will intentionally delay triaging of your ticket?

• I understand

Which connector are you using (React/Angular/etc)?

React

Bug Description

It's like custom view content unmounts and mounts again when fullcalendar props change, it causes content flickering when I want to update events or the header toolbar.

[acerix]

I believe it's not intended to initialize the calendar after useState in this way since that causes the calendar component to reinitialize when the state is changed, which would hurt performance. You can instead update events using the API, for example providing them "as a function", to avoid that:

https://fullcalendar.io/docs/events-function

Related issue here:
#7230

[Azaryan-A]

Custom view content 'flickers' even if updating some props via API. for example "customButtons". This problem occurred after updating the version of fullcalendar from v5 to v6. Please check this example - https://stackblitz.com/edit/github-urj6el-oghacn?file=src%2FDemoApp.jsx

[nandorojo]

I have a similar issue. Whenever I use eventContent's content injection with JSX, the calendar has very noticeable flickers.

I can provide a reproduction tomorrow if it's useful. I'm also willing to sponsor a solution @acerix for what that's worth!

[austintackaberry]

I am experiencing the same issue as @nandorojo. Whenever I use eventContent's content injection with JSX and I issue a refetchEvents call, all of the events flicker. If I remove eventContent, the flicker goes away. On version 6.1.4

[nandorojo]

I wonder if there is any potential fix. Or if I could get pointed to the code in charge of this that I could play with and try to patch.

[nandorojo]

It's especially noticeable if the max dates isn't true and the order of events changes. Here's a video: https://www.loom.com/share/5626f7eac906400ba46819db73e1590a

[arshaw]

This should be fixed in v6.1.7

Please see my comment on a related issue:
#7165 (comment)

Please post here on this ticket if you're still experiencing problems after upgrading.