react-persistent-state

Tools to simply persist component state in the local storage.

Installation

npm install --save react-persistant-state

or

npm install --save https://github.com/alexandreannic/react-persistent-state.git

Usage

From class component

Simply extend PersistentComponent from react-persistent-state instead of Component from react.

import React from 'react'
import {PersistentComponent} from 'react-persistent-state'

export class PersistentInput extends PersistentComponent {
  state = {
    value: '',
  }

  handleChange = event => {
    this.setState({value: event.target.value})
  }

  render() {
    return (
      <div>
        <input value={this.state.value} onChange={this.handleChange}/>
        <button onClick={this.clearPersistentState}>Clear from local storage</button>
      </div>
    )
  }
}

From functional component

Use usePersistentState instead of useState. It works the same except that it exposes another method to clear related local storage save.

import React from 'react'
import {usePersistentState} from 'react-persistent-state'

export function PersistentCounterHook() {
  const [value, setValue, unpersist] = usePersistentState(0)
  return (
    <div>
      <button onClick={() => setValue((prev) => prev + 1)}>{value}</button>
      <button onClick={unpersist}>Clear from local storage</button>
    </div>
  )
}

Limitation

When a component with persistant state is used multiples times inside a same component, react-persistent-state is not able to generate an unique key to distinguish them from the local storage.

In this case you must provide an unique key as shown below:

Usage

function App() {
  return (
    <>
      <Persistent persistentKey={1}/>
      <Persistent persistentKey={2}/>
    </>
  )
}

Class component implementation

export class Persistent extends PersistentComponent {
  constructor(props) {
    super(props, props.persistentKey)
  }
  ...
}

Functional component implementation

export const Persistent = ({persistentKey}) => {
  const [value, setValue, clearValue] = usePersistentState<string>(0, persistentKey)
  ...
}