readme.md

use-session-storage-state

React hook that persist data in sessionStorage

Install

React 18 and above:

npm install use-session-storage-state

⚠️ React 17 and below. For docs, go to the react-17 branch.

npm install use-session-storage-state@17

Why

• Clone of use-local-storage-state that I've been actively maintaining for the past 4 years.
• SSR support.
• Works with concurrent rendering and React 19.
• Handles the Window storage event and updates changes across iframe's. Disable with storageSync: false.
• In-memory fallback when sessionStorage throws an error and can't store the data. Provides a isPersistent API to let you notify the user their data isn't currently being stored.
• Aiming for high-quality with my open-source principles.

Usage

import useSessionStorageState from 'use-session-storage-state'

export default function Todos() {
    const [todos, setTodos] = useSessionStorageState('todos', {
        defaultValue: ['buy avocado', 'do 50 push-ups']
    })
}

Todo list example

import React, { useState } from 'react'
import useSessionStorageState from 'use-session-storage-state'

export default function Todos() {
    const [todos, setTodos] = useSessionStorageState('todos', {
        defaultValue: ['buy avocado']
    })
    const [query, setQuery] = useState('')

    function onClick() {
        setQuery('')
        setTodos([...todos, query])
    }

    return (
        <>
            <input value={query} onChange={e => setQuery(e.target.value)} />
            <button onClick={onClick}>Create</button>
            {todos.map(todo => (
                <div>{todo}</div>
            ))}
        </>
    )
}

Notify the user when sessionStorage isn't saving the data using the isPersistent property

There are a few cases when sessionStorage isn't available. The isPersistent property tells you if the data is persisted in sessionStorage or in-memory. Useful when you want to notify the user that their data won't be persisted.

import React, { useState } from 'react'
import useSessionStorageState from 'use-session-storage-state'

export default function Todos() {
    const [todos, setTodos, { isPersistent }] = useSessionStorageState('todos', {
        defaultValue: ['buy avocado']
    })

    return (
        <>
            {todos.map(todo => (<div>{todo}</div>))}
            {!isPersistent && <span>Changes aren't currently persisted.</span>}
        </>
    )
}

Removing the data from sessionStorage and resetting to the default

The removeItem() method will reset the value to its default and will remove the key from the sessionStorage. It returns to the same state as when the hook was initially created.

import useSessionStorageState from 'use-session-storage-state'

export default function Todos() {
    const [todos, setTodos, { removeItem }] = useSessionStorageState('todos', {
        defaultValue: ['buy avocado']
    })

    function onClick() {
        removeItem()
    }
}

Why does my component re-renders twice?

If you are hydrating your component (for example, if you are using Next.js), your component might re-render twice. This is behavior specific to React and not to this library. It's caused by the useSyncExternalStore() hook. There is no workaround. This has been discussed in the issues: astoilkov/use-local-storage-state#56.

If you want to know if you are currently rendering the server value you can use this helper function:

function useIsServerRender() {
  return useSyncExternalStore(() => {
    return () => {}
  }, () => false, () => true)
}

API

useSessionStorageState(key: string, options?: SessionStorageOptions)

Returns [value, setValue, { removeItem, isPersistent }] when called. The first two values are the same as useState(). The third value contains two extra properties:

• removeItem() — calls sessionStorage.removeItem(key) and resets the hook to it's default state
• isPersistent — boolean property that returns false if sessionStorage is throwing an error and the data is stored only in-memory

key

Type: string

The key used when calling sessionStorage.setItem(key) and sessionStorage.getItem(key).

⚠️ Be careful with name conflicts as it is possible to access a property which is already in sessionStorage that was created from another place in the codebase or in an old version of the application.

options.defaultValue

Type: any

Default: undefined

The default value. You can think of it as the same as useState(defaultValue).

options.storageSync

Type: boolean

Default: true

Setting to false doesn't subscribe to the Window storage event. If you set to false, updates won't be synchronized across iframes.

Note: Unlike localStorage, sessionStorage doesn't fire the storage event across tabs and windows.

options.serializer

Type: { stringify, parse }

Default: JSON

JSON does not serialize Date, Regex, or BigInt data. You can pass in superjson or other JSON-compatible serialization library for more advanced serialization.

Related

• use-storage-state — Supports localStorage, sessionStorage, and any other Storage compatible API.
• use-local-storage-state — A clone of this library but for localStorage.
• use-db — Similar to this hook but for IndexedDB.
• local-db-storage — Tiny wrapper around IndexedDB that mimics localStorage API.