Callback

useAtomCallback

参考： https://github.com/pmndrs/jotai/issues/60

使用方法

useAtomCallback<Result, Args extends unknown[]>(
  callback: (get: Getter, set: Setter, ...arg: Args) => Result,
  options?: Options
): (...args: Args) => Result

这个钩子用于命令式地与原子进行交互。 它接受一个回调函数，该函数的工作方式类似于原子写入函数， 并返回一个返回原子值的函数。

传递给钩子的回调必须是稳定的（应该用 useCallback 包装）。

示例

import { useEffect, useState, useCallback } from 'react'
import { Provider, atom, useAtom } from 'jotai'
import { useAtomCallback } from 'jotai/utils'

const countAtom = atom(0)

const Counter = () => {
  const [count, setCount] = useAtom(countAtom)
  return (
    <>
      {count} <button onClick={() => setCount((c) => c + 1)}>+1</button>
    </>
  )
}

const Monitor = () => {
  const [count, setCount] = useState(0)
  const readCount = useAtomCallback(
    useCallback((get) => {
      const currCount = get(countAtom)
      setCount(currCount)
      return currCount
    }, []),
  )
  useEffect(() => {
    const timer = setInterval(async () => {
      console.log(readCount())
    }, 1000)
    return () => {
      clearInterval(timer)
    }
  }, [readCount])
  return <div>current count: {count}</div>
}

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