设置 React useReducer 的最佳方法 [英] Best way to setup a React useReducer

问题描述

我将这个 reducer.js 文件设置为使用 React 的 useReducer

I setup this reducer.js file to use React's useReducer

https://reactjs.org/docs/hooks-reference.html#usereducer

import {useReducer} from 'react';

const initialState = {
  test: 0,
};

const reducer = (state, action) => {
  switch (action.type) {
    case 'reset':
      return initialState;
    case 'addTest':
      return {test: state.test + 1};
    case 'removeTest':
      return {test: state.test - 1};
  }
};

export const getReducer = () => {
  return useReducer(reducer, initialState);
};

现在我可以在不同的渲染函数中通过 getReducer 获取状态和分派:

Now I can get state and dispatch via getReducer in different rendering functions:

import React from 'react';
import ReactDOM from 'react-dom';

import {getReducer} from './reducer';

const Button = (props) => (
  <button
    type="button"
    onClick={() => props.dispatch({type: props.type})}>
    {props.children}
  </button>
);

const App = () => {
  const [state, dispatch] = getReducer();
  return (
    <React.Fragment>
      {state.test}
      <Button dispatch={dispatch} type="addTest">Add 1</Button>
      <Button dispatch={dispatch} type="removeTest">Remove 1</Button>
      <Button dispatch={dispatch} type="reset">Reset</Button>
    </React.Fragment>
  );
};

ReactDOM.render(<App />, document.getElementById('root'));

传递dispatch 函数并让其他组件调用props.dispatch 确实感觉很奇怪.有没有更简洁的方法来设置?

It does feel weird passing the dispatch function around and having other components call props.dispatch. Is there a cleaner way to set this up?

如果你想尝试不同的模式，我在这里设置了一个仓库:https://github.com/dancrew32/hooks

I setup a repo here if you want to try out different patterns: https://github.com/dancrew32/hooks

推荐答案

如何定义您的操作并将它们映射到您的减速器?

How about defining your actions and mapping them to your reducer?

const mapDispatch => dispatch => ({
  reset: () => dispatch({ type: 'reset' }),
  addTest: () => dispatch({ type: 'addTest' }),
  removeTest: () => dispatch({ type: 'removeTest' })
})

const Button = (props) => (
  <button
    type="button"
    onClick={props.onClick}>
    {props.children}
  </button>
);

const App = () => {
  const [state, dispatch] = getReducer();
  const actions = mapDispatch(dispatch)
  return (
    <React.Fragment>
      {state.test}
      <Button onClick={actions.addTest}>Add 1</Button>
      <Button onClick={actions.removeTest}>Remove 1</Button>
      <Button onClick={actions.reset}>Reset</Button>
    </React.Fragment>
  );
};

这里没有什么新鲜事；只是对 react-redux 如何做事的模仿.

Nothing new here; just a copycat of how react-redux does things.

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