[REACT] [Intermittent] App freezes during drag&drop

[dpontes]

Hello Bryntum Team, some users were reporting an issue that happens from time to time. Not easy to reproduce.

When dragging and dropping events, there's a small chance that the application freezes and users are forced to refresh the page and potentially lose any unsaved progress they had.

We noticed that when this "freeze/crash" happens, the following error is displayed in the console.

The error happens because in the version we had (5.3.5) the eventRecord type couldn't be undefined, but seems like in rare cases we do receive undefined for it, causing the exception when trying to do "undefined.get()". In theory that should be fixed now that we properly verify with "?" before trying to call get.
But I still need to understand if this console error is related or not with the freezing issue.

The version this issue is happening is 5.3.5, and we recently upgraded to 6.1.7. As you can see in the attachment, after the upgrade, now the types for the params are optional.

I would like to know if:

• This intermittent freezing issue was something known back in 5.3.5 and if 6.1.7 would potentially fix it
• Why eventRecord can be undefined during a drag&drop? What are the cases where it will be defined and undefined when getDateConstraints is triggered?

[marcio]

Hey dpontes,

Thanks for reaching out.

Regarding the intermittent freezing issue, there were several improvements and bug fixes made between versions 5.3.5 and 6.1.7, so upgrading might help resolve the issue. However, without specific details, it's hard to confirm if the upgrade will completely fix the freezing problem.

As for the eventRecord being undefined during drag-and-drop, this can happen if the event being dragged is not properly initialized or if there is a timing issue where the event data is not yet available. The getDateConstraints method should ideally be called with a valid eventRecord, but if the event is not fully loaded or there is a race condition, it might be undefined.

To further investigate, you might want to add logging or checks to ensure that the event data is fully loaded before drag-and-drop operations are initiated. Additionally, reviewing any custom logic or asynchronous operations that might affect event loading could be beneficial.

If you continue to experience issues, providing more detailed logs or code snippets could help in diagnosing the problem.

[dpontes]

Appreciate the response Marcio, I will communicate and observe if this intermittent issue will persist after users start to adopt the new released version of the app where we upgraded to 6.1.7

[marcio]

Thanks for the feedback. Please let us know if you need any further help.