immerx-react v1.0.1

React bindings for ImmerX

Basic usage

The following example assumes that you are already familiar with ImmerX

index.js

import React from 'react'
import { render } from 'react-dom'
import { create } from '@immerx/react'

import App from './App'

import './styles.css'

create({
  counter: { count: 0 },
  times: 0,
})

const rootElement = document.getElementById('root')
render(<App />, rootElement)

App.js

import React from 'react'
import { useImmerx } from '@immerx/react'

import Counter from './Counter'

export default function App() {
  const [state] = useImmerx()

  return (
    <>
      <Counter />
      <p>You clicked: {state.times} times </p>
    </>
  )
}

Counter.js

import React from 'react'
import { useImmerx } from '@immerx/react'

const lens = {
  get: state => state.counter,
  set: (stateDraft, counter) => {
    stateDraft.counter = counter
    stateDraft.times += 1
  },
}

export default function Counter() {
  const [state, update] = useImmerx(lens)

  const increment = () => update(draft => void (draft.count += 1))
  const decrement = () => update(draft => void (draft.count -= 1))

  return (
    <>
      <p>count: {state.count}</p>
      <button onClick={decrement}> - </button>
      <button onClick={increment}> + </button>
    </>
  )
}

NOTE: Always memoize your lenses or define them outside the function if they're not derived from props, because the state$ observable synchronously emits the current state value to incoming subscribers.

Otherwise, the isolated state will emit an update -> the lens is re-created -> a new isolated state is created with the new lens and it emits another update -> the lens is re-created ... :boom: :fire: :fire: