Component State
To isolate component state for reusability, Valtio must live in the React lifecycle. You can wrap a proxy
in a ref, passing it with props or 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>
</>
)
}
Codesandbox example
Alternatives
If you are not happy with useRef usage, consider:
- use-constant
- bunshi
- You may also create custom hooks wrapping useContext and optionally useSnapshot.