adding checkbox causing more re renders [performance]

[ManuSunny18]

Describe the bug
adding checkboxes causing lot of re renders, component is stuck when you have lot of child elements

To Reproduce
Please refer this sandbox demo

Expected behavior
component should not re render a lot.

[Joshua-hypt]

I agree that it seems slow

[ManuSunny18]

Hi @lukasbach , @Joshua-hypt ,
I have identified the fix; however, I am uncertain if it might have unintended side effects elsewhere. The issue arises with checkboxes in conjunction with the async-loader. Currently, we set loadingCheckPropagationItems within the checkbox feature, so it is unnecessary to set loadingItemChildrens again within the async-loader’s loadChildrenIds method.
We can therefore omit the call to tree.applySubStateUpdate("loadingItemChildrens" in loadingItemChildrens), which should resolve the issue. Consequently, the modification should be confined to the async-loader, ensuring that these two features remain properly decoupled.
Please let me know your thoughts.

[ouali-ls2]

We are in the same situation using the async-loader and virtualization for 5000 items, is there any updates ?

[lukasbach]

Hi everyone, thanks for the input. Due to some consecutive trips, I haven't had time to look into this yet, I'll try to find a fix for this next week.

[lukasbach]

So I've had a look, and surprisingly, what makes a pretty big difference is the way how React is used:

Using import ReactDOM from "react-dom"; ReactDOM.render(...) triggers tons of rerenders, whereas import { createRoot } from "react-dom/client"; createRoot(...).render(...) causes a much more sane behavior, and when using this pattern instead in the provided demo with React 19, it significantly reduces the number of rerenders. By best guess is that the new React DOM API is a lot better at batching together subsequent state updates, and Headless Tree sometimes makes assumptions that state updates triggered within the same sync execution thread are batched together.

Nevertheless, I still found some situations where checkboxes trigger more state updates than would be necessary, particularly if an item load is triggered which is already loading, redundant state updates are scheduled, or checkbox click propagation triggers "start loading" and "stop loading" state updates even if the load happens immediately, I've improved those behaviors in the latest version 1.6.0.