@rpgtec/use-storage

1. Make state shareable without using context
2. Make state persistent using localStorage
3. Make state accessible without re-rendering component
4. Make state extensible using your own custom storage

Demo

Installation

# Using npm
npm i -S @rpgtec/use-storage
# Using yarn
yarn add @rpgtec/use-storage

Quick Start

import { useLocalStorage, setLocalStorage } from '@rpgtec/use-storage'

function App() {
  // Set the key name as the first argument
  const [count, setCount] = useLocalStorage('count', 0)
  return (
    <div>
      {/* Usage is almost the same as setState */}
      <div>count: {count}</div>
      <button onClick={() => setCount(count + 1)}>Increment</button>
      <button onClick={() => setCount(0)}>Reset</button>
      {/* The state is remembered even if you reload */}
      <button onClick={() => window.location.reload()}>Reload</button>
    </div>
  )
}

// You can access the state without dependencies
setInterval(() => setLocalStorage('count', x => x + 1), 1000)

Interface

const [state, setState] = useStorage(key, initialState, storage)

Returned value

The usage of state and setState is almost the same as that of useState

Arguments

name	type	description
key	string	Set a key name to identify what the state is. Synchronize states with the same key.
initialState	any	Return initialState when the state is undefined. If initialState is a function, return the result of the function call.
storage	object	[Optional] default storage is a wrapper of simple object in memory. You can also use your own custom storage.

API

useStorage(key, initialState, storage)
getStorage(key, initialState, storage)
setStorage(key, value, storage)

useLocalStorage(key, initialState)
getLocalStorage(key, initialState)
setLocalStorage(key, value)

useSessionStorage(key, initialState)
getSessionStorage(key, initialState)
setSessionStorage(key, value)

Usage

1. Make state shareable without using context

import { useStorage } from '@rpgtec/use-storage'

function ComponentA() {
  // Set the key name as the first argument
  const [query, setQuery] = useStorage('query', '')
  return <input value={query} onChange={event => setQuery(event.target.value)} />
}

function ComponentB() {
  // Synchronize states with the same key
  const [query, setQuery] = useStorage('query', '')
  return <input value={query} onChange={event => setQuery(event.target.value)} />
}

2. Make state persistent using localStorage

import { useLocalStorage } from '@rpgtec/use-storage'

function ComponentA() {
  // To make a persistent state, use useLocalStorage instead of useStorage
  const [query, setQuery] = useLocalStorage('query', '')
  return <input value={query} onChange={event => setQuery(event.target.value)} />
}

function ComponentB() {
  // A persistent state is also synchronized with the state of the same key
  // And, state is remembered even if you reload
  const [query, setQuery] = useLocalStorage('query', '')
  return <input value={query} onChange={event => setQuery(event.target.value)} />
}

3. Make state accessible without re-rendering component

import { useStorage, setStorage, getStorage } from '@rpgtec/use-storage'

function CountView() {
  console.log('Render: CountView') //=> re-render when the count is updated
  const [count] = useStorage('count', 0)
  return <div>count: {count}</div>
}

// No need to re-render this component when the count is updated.
// So, use setStorage / getStorage instead of useStorage.
function CountTool() {
  console.log('Render: CountTool') //=> only first rendering
  return (
    <div>
      <button onClick={() => setStorage('count', x => x + 1)}>count up</button>
      <button onClick={() => setStorage('count', 0)}>count reset</button>
      <button onClick={() => console.log(getStorage('count'))}>get count</button>
    </div>
  )
}

4. Make state extensible using your own custom storage

import { useStorage } from '@rpgtec/use-storage'

// Storage must have get / set methods
const numberOnlyStorage = (obj => ({
  get: key => {
    return obj[key]
  },
  set: (key, value = '') => {
    // Convert value to numbers only!
    obj[key] = value.replace(/[^0-9]/g, '').replace(/^0+([0-9])/, '$1') || '0'
    return obj[key]
  },
}))({})

function Component() {
  const [number, setNumber] = useStorage('number', '0', numberOnlyStorage)
  return <input value={number} onChange={event => setNumber(event.target.value)} />
}

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Happy hacking!