“Mail” example in shadcn-ui/ui manages state using Jotai.

#javascript #jotai #opensource #nextjs

Since I am building shadcn-ui/ui from scratch and also documenting how to do so alongside, I am aware that it will take quite some time to understand the code and write it from scratch and prepare the content. I am not rushing the process by directly copying and pasting, instead I am trying to understand the concepts, code, patterns and strategies that can be applied in other projects. This is how I picked up that “mail” example in shadcn-ui/ui uses Jotai for state management.

In this article, you will learn the below concepts:

What is Jotai?
Jotai usage example.
Jotai configuration in Next.js
How is the Jotai configured in Shadcn-ui/ui?
How is Jotai used in Shadcn-ui/ui?

What is Jotai?

Jotai is a primitive and flexible state management library for React and is written by Daishi Kato, also the maintainer of zustand. Jotai takes an atomic approach, meaning you will create primitive and derived atoms to build state.

Build shadcn-ui/ui from scratch.

Jotai usage example.

Primitive atoms:

import { atom } from 'jotai'

const countAtom = atom(0)

const countryAtom = atom('Japan')

const citiesAtom = atom(\['Tokyo', 'Kyoto', 'Osaka'\])

const animeAtom = atom(\[
  {
    title: 'Ghost in the Shell',
    year: 1995,
    watched: true
  },
  {
    title: 'Serial Experiments Lain',
    year: 1998,
    watched: false
  }
\])

Derived atoms:

const progressAtom = atom((get) => {
  const anime = get(animeAtom)
  return anime.filter((item) => item.watched).length / anime.length
})

Jotai configuration in Next.js

Next.js (app directory)

Create the provider in a separate client component. Then import the provider into the root layout.js server component.

// ./components/providers.js
'use client'

import { Provider } from 'jotai'

export const Providers = ({ children }) => {
  return (
    <Provider>
      {children}
    </Provider>
  )
}


// ./app/layout.js
import { Providers } from '../components/providers'

export default function RootLayout({ children }) {
  return (
    <html lang="en">
      <body>
        <Providers>
          {children}
        </Providers>
      </body>
    </html>
  )
}