reactjs / reactjs/react.dev

useInsertionEffect other use-case

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Description

Hello,

in the docs it is stated that useInsertionEffect should be used only by css-in-js library authors, I think I've came across an other use case. I'm using forwardRef with a type HTMLDivElement[] where through a callback ref I'm pushing the refs in to the array as so ref={(ref) => ref && innerRef.current.push(ref)} and syncing it outside with a useImperativeHandle

However this needs a cleanup whenever the component re-renders, since useInsertionEffect fires sync BEFORE the dom is mutated, it is perfect for the cleanup of the innerRef array.

The code is as follows

const ComponentReturningAnArray = React.forwardRef<HTMLDivElement[], { data: string[] }>(({array}, outerRef) => {
const innerRef = useRef<HTMLDivElement[]>([]);

useImperativeHandle<HTMLDivElement[], HTMLDivElement[]>(outerRef, () => innerRef.current, [innerRef.current]);

useInsertionEffect(() => {
    innerRef.current = [];
  });

return (
     <>
        {
             data.map((d) => (<div ref={(ref) => ref && innerRef.current.push(ref)}>{d}</div>))
        }
    </>
)
});

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  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the documentation statement about useInsertionEffect and the provided ComponentReturningAnArray example. Check whether this ref-collection cleanup is an intended use case and determine how the documentation should describe it. Done means the guidance accurately reflects the supported use cases and the example is addressed.

Written by the indexing model from the issue text.

Assessment

Tech stack
javascript, react
Domain
documentation
Issue type
Documentation
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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