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@thebuilder
Last active January 16, 2024 13:50
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Hook with ref callback
import React, {useCallback, useRef} from 'react'
function useHookWithRefCallback() {
const ref = useRef(null)
const setRef = useCallback(node => {
if (ref.current) {
// Make sure to cleanup any events/references added to the last instance
}
if (node) {
// Check if a node is actually passed. Otherwise node would be null.
// You can now do what you need to, addEventListeners, measure, etc.
}
// Save a reference to the node
ref.current = node
}, [])
return [setRef]
}
function Component() {
// In your component you'll still recieve a `ref`, but it
// will be a callback function instead of a Ref Object
const [ref] = useHookWithRefCallback()
return <div ref={ref}>Ref element</div>
}
@z2lai
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z2lai commented Jul 9, 2020

Nice and simple example, but in any case, wouldn't you want to return both ref and setRef from the custom hook like this, const [ref, setRef] = useHookWithRefCallback(), so you can use the ref in addition to setting it?

@thebuilder
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Author

I guess you could do that, but be careful. There's a couple of gotchas.

  1. Setting ref.current doesn't trigger a render update, so you can't be sure of when it's set/updated.
  2. If you return the ref itself, it would allow other components to potentially change the ref.current

@claytonrothschild
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Excellent gist!

If you return the ref itself, it would allow other components to potentially change the ref.current

@thebuilder, I'm trying to understand how this would happen. Are you able to describe this risk further with a quick example? Thank you.

@thebuilder
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Setting .current doesn't trigger a rerender, so things might not work like you expect.

function Component() {
  // In your component you'll still recieve a `ref`, but it 
  // will be a callback function instead of a Ref Object
  const [ref] = useHookWithRef()
  
  ref.current = 'Not your div'

  return <div ref={ref}>Ref element</div>
}

@reorx
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reorx commented Jan 16, 2024

I'm wondering why you're returning [setRef] instead of setRef directly. Is there a specific reason for this?

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