16 lines
485 B
TypeScript
16 lines
485 B
TypeScript
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import { useEffect, useRef } from 'react'
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export default function usePrevious(value) {
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// The ref object is a generic container whose current property is mutable ...
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// ... and can hold any value, similar to an instance property on a class
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const ref = useRef()
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// Store current value in ref
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useEffect(() => {
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ref.current = value
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}, [value]) // Only re-run if value changes
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// Return previous value (happens before update in useEffect above)
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return ref.current
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}
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