Package Exports

use-callback-ref

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Readme

🤙 use-callback-ref 📞

Hey! Your ref just got changed!

--- > Keep in mind that useRef doesn't notify you when its content changes. Mutating the .current property doesn't cause a re-render. If you want to run some code when React attaches or detaches a ref to a DOM node, you may want to use ~~a callback ref instead~~ .... __useCallbackRef__ instead.

– Hooks API Reference

API

useRef API

API is 99% compatible with React createRef and useRef, and just adds another argument - callback, which would be called on ref update.

createCallbackRef(callback) - (aka React.createRef) would call provided callback when ref is changed.
useRef(initialValue, callback) - (aka React.useRef)would call provided callback when ref is changed.
callback in both cases is callback(newValue, oldValue). Callback would not be called if newValue and oldValue is the same.

import {useRef, createRef, useState} from 'react';
import {useCallbackRef, createCallbackRef} from 'use-callback-ref';

const Component = () => {
  const [,forceUpdate] = useState();
  // I dont need callback when ref changes
  const ref = useRef(null); 
  
  // but sometimes - it could be what you need
  const anotherRef = useCallbackRef(null, () => forceUpdate());
  
  useEffect( () => {
    // now it's just possible
  }, [anotherRef.current]) // react to dom node change
}

💡 You can use useCallbackRef to convert RefObject into RefCallback, creating bridges between the old and the new code

// some old component
const onRefUpdate = (newValue) => {...}
const refObject = useCallbackRef(null, onRefUpdate);
// ...
<SomeNewComponent ref={refObject}/>

Additional API

mergeRefs

mergeRefs(refs: arrayOfRefs, [defaultValue]):ReactMutableRef - merges a few refs together

import React from 'react'
import {mergeRefs} from 'use-callback-ref'

const MergedComponent = React.forwardRef(function Example(props, ref) {
  const localRef = React.useRef()
  return <div ref={mergeRefs([localRef, ref])} />
})

based on https://github.com/smooth-code/react-merge-refs, just exposes RefObject, instead of callback

When developing low level UI components, it is common to have to use a local ref but also support an external one using React.forwardRef. Natively, React does not offer a way to set two refs inside the ref property. This is the goal of this small utility.

License

MIT