使用 React 钩子的冗余代码 [英] Redundant piece of code using React hooks

问题描述

有固定数量的设置决定组件是否应该可见，即:

There's a fixed number of settings that determine whether the component should be visible, i.e.:

const restrictions = {
  isLogged: true, // TRUE stands for: check if the condition is met
  hasMoney: true,
  didWinYesterday: false,
}

对于每个 restrictions 键，我用 useState 创建了一个状态，并用 false 初始化它们，例如:

For each restrictions key, I've created a state with useState and initialized them all with false, like:

const [isUserLogged, setIsUserLogged] = useState(false)
const [hasUserMoney, setHasUserMoney] = useState(false)
const [didUserWinYday, setDidUserWinYday] = useState(false)

接下来，我使用 useEffect 检查每个条件并相应地更新状态:

Next, I am checking against each condition with useEffect and updating the state accordingly:

useEffect(() => {
 const checkIfUserIsLogged = async () => {
   // calling an API to get boolean
   const isLogged = await API.call()

   setIsUserLogged(isLogged)
 }

  // If the restriction is set to false, ignore checking and set relevant state
  if (!restrictions.isLogged) {
    setIsUserLogged(true)
    return
  }

  checkIfUserIsLogged()
}, [restrictions.isLogged])

最后，我正在检查我是否应该渲染实际组件或者我应该像这样提前中断:

Finally, I am checking if I should render the actual component or should I break early like so:

if (!isUserLogged) return <p>User not logged in.</p>

useEffect 代码和上面的检查一共重复了 3 次.每次重复都在进行不同的 API 调用并更新不同的状态，但整体结构保持不变.我希望我能做得更干，但不知道如何开始.欢迎任何提示，谢谢！

The useEffect code and the check above is repeated 3 times in total. Each of the repetition is making different API call and is updating different state, but the overall structure stays the same. I wish I could do it more DRY but not sure how to get started. Any tips are welcome, thanks!

推荐答案

我会将单个原子重构为一个自定义的 useRestrictionState 原子，该原子在内部处理效果:

I'd refactor a single atom into a custom useRestrictionState atom that internally deals with the effect:

const restrictions = {
  isLogged: true, // TRUE stands for: check if the condition is met
  hasMoney: true,
  didWinYesterday: false,
};

function useRestrictionState(restrictionFlag, apiFunc) {
  const [flag, setFlag] = React.useState(undefined);
  useEffect(() => {
    if (!restrictionFlag) {
      setFlag(true);
    } else {
      apiFunc().then((result) => setFlag(result));
    }
  }, [restrictionFlag]);
  return flag;
}

function Component() {
  const isUserLogged = useRestrictionState(restrictions.isLogged, getLoginState);
  const hasUserMoney = useRestrictionState(restrictions.hasMoney, getUserMoney);
  const didUserWinYday = useRestrictionState(restrictions.didWinYesterday, getUserDidWinYesterday);
}

如果您总是需要所有这些，您可以自然地将其包装在另一个自定义钩子中:

If you always need all of them, you can naturally wrap this in another custom hook:

function useUserRestrictionState(restrictions) {
  const isUserLogged = useRestrictionState(restrictions.isLogged, getLoginState);
  const hasUserMoney = useRestrictionState(restrictions.hasMoney, getUserMoney);
  const didUserWinYday = useRestrictionState(restrictions.didWinYesterday, getUserDidWinYesterday);
  return { isUserLogged, hasUserMoney, didUserWinYday };
}

function Component() {
  const { isUserLogged, hasUserMoney, didUserWinYday } = useUserRestrictionState(restrictions);
}

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