how-to-use-with-context.mdx

title
How to use with context

How to use with context

To make a valtio state only live in React lifecycle, you can create a state in a ref, and you can pass it with props or context.

A basic pattern with context

import { createContext, useContext } from 'react'
import { proxy, useSnapshot } from 'valtio'

const MyContext = createContext()

const MyProvider = ({ children }) => {
  const state = useRef(proxy({ count: 0 })).current
  return <MyContext.Provider value={state}>{children}</MyContext.Provider>
}

const MyCounter = () => {
  const state = useContext(MyContext)
  const snap = useSnapshot(state)
  return (
    <>
      {snap.count} <button onClick={() => ++state.count}>+1</button>
    </>
  )
}

Alternatives

If you are not happy with useRef usage, consider:

• use-constant
• bunshi
• You can create custom hooks to useContext and optionally useSnapshot

Bunshi example

https://codesandbox.io/s/77r53c?file=/molecules.ts