ui/frontend/src/utils/localStorage.ts

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 { useState, useEffect } from "react";

const getStorageValue = (
  key: string,
  defaultValue: string | undefined
): string | undefined => {
  const saved = localStorage.getItem(key);
  const initial = saved !== undefined ? saved : undefined;
  return initial || defaultValue;
};

export const useLocalStorage = (
  key: string,
  defaultValue: string | undefined
): [
  string | undefined,
  React.Dispatch<React.SetStateAction<string | undefined>>,
] => {
  const [value, setValue] = useState(() => {
    return getStorageValue(key, defaultValue);
  });

  useEffect(() => {
    if (value === undefined) {
      localStorage.removeItem(key);
    } else {
      localStorage.setItem(key, value);
    }
  }, [key, value]);

  return [value, setValue];
};