Medplum

// SPDX-FileCopyrightText: Copyright Orangebot, Inc. and Medplum contributors // SPDX-License-Identifier: Apache-2.0 import { useEffect, useRef } from 'react'; /** * React Hook to keep track of the passed-in value from the previous render of the containing component. * @param value - The value to track. * @returns The value passed in from the previous render. */ export function usePrevious<T>(value: T): T | undefined { const ref = useRef<T>(undefined); useEffect(() => { ref.current = value; }); return ref.current; }