/** * * Copyright 2023-2024 InspectorRAGet Team * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * **/ import { useEffect, useRef } from 'react'; /** * Returns the value passed to the hook on previous render. * * Yields `undefined` on first render. * * @param value Value to yield on next render */ export default function usePrevious(value?: T): T | undefined { const prev = useRef(); useEffect(() => { prev.current = value; }); return prev.current; }