Storeon sessionStorage

Tiny module for Storeon to store and sync state to sessionStorage. It restores state from sessionStorage during page loading and saves state on every change.

The methods are the same of localStorage, but there are significant limitations:

• sessionStorage exists only within current browser tab.
  • Another tab with the same page will have a different storage.
  • But it's divided between iframe on the same tab (provided that they are from the same source).
• Data continues to exist after reloading the page, but not after closing/opening browser tab.

It is just 172 bytes module (it uses Size Limit to control the size) without any dependencies.

Please note: this module is a fork of localStorage by Ivan Menshykov. Because of this, init version of module is v0.6.3 (latest version of @storeon/localstorage when fork).

Installation

npm install --save storeon-sessionstorage

Usage

If you want to store and sync state to sessionStorage you should import the persistState from storeon-sessionstorage and add this module to createStore.

import createStore from 'storeon'
import persistState from 'storeon-sessionstorage'

let name = store => {
  store.on('@init', () => ({ name: '' }))
  store.on('save', (state, name) => ({ name: name }))
};

const store = createStore([name, persistState(['name'])])

Here you can see that the form ask user the name and after that show this name.

import useStoreon from 'storeon/react' // or storeon/preact for Preact
import StoreContext from 'storeon/react/context' // or storeon/preact/context for Preact

const Form = () => {
  const { dispatch, name } = useStoreon('name')

  return (
    <React.Fragment>
      {name !== '' && <h3>Hello {name}!</h3>}
      {name === '' && (
        <div>
          <label>Name</label>
          <input type='text' id='name' />
          <br />
          <button
            onClick={() =>
              dispatch('save', document.getElementById('name').value)
            }
          >
            Save
          </button>
        </div>
      )}
    </React.Fragment>
  )
}

Event after refresh the page the state is updating from sessionStorage. And user see the greeting message.

persistState(paths, config)

type paths = Void | Array<String>

If no pass the paths value then persistState store in local storage all state.

type config.key = String

Default value of config.key is storeon. This key is using to store data in local storage.

Acknowledgments

This module based on @storeon/localstorage.

LICENSE

MIT