README

use-persisted-state

A custom React Hook that provides a multi-instance, multi-tab/browser shared and persistent state.

use-persisted-state is not a hook itself, but is a factory that accepts a storage key and an optional storage provider (default = localStorage) and returns a hook that you can use as a direct replacement for useState.

Features

💾 Persists the state to localStorage

🖥 Syncs between tabs and/or browser windows

📑 Shares state w/multiple hooks on a page

Requirement

To use use-persisted-state, you must use react@16.8.0 or greater which includes Hooks.

Installation

$ npm i use-persisted-state

Example

Let's take a look at how you can use use-persisted-state. Here we have an example of a typical up/down counter.

import { useState } from 'react';

const useCounter = initialCount => {
  const [count, setCount] = useState(initialCount);

  return {
    count,
    increment: () => setCount(currentCount => currentCount + 1),
    decrement: () => setCount(currentCount => currentCount - 1),
  };
};

export default useCounter;

Let's replace the import of react with an import from use-persisted-state. And we'll call createPersistedState (the factory function). This will return a useCounterState hook that we can use in place of useState.

The complete code is as follows.

import createPersistedState from 'use-persisted-state';
const useCounterState = createPersistedState('count');

const useCounter = initialCount => {
  const [count, setCount] = useCounterState(initialCount);

  return {
    count,
    increment: () => setCount(currentCount => currentCount + 1),
    decrement: () => setCount(currentCount => currentCount - 1),
  };
};

export default useCounter;

The state is shared with any other hook using the same key, either on the same page, across tabs, or even browser windows.

For example, open two copies of your app in two tabs or even two windows. Any changes to state in one tab will be rendered on the other tab.

You can also close the browser and the next time you run your app, the state will be rendered as it was before you closed your browser.