MobX 用于状态治理,简略高效。本文将于 React 上介绍如何开始,包含了:

  • 理解 MobX 概念
  • 从零筹备 React 利用
  • MobX React.FC 写法
  • MobX React.Component 写法

能够在线体验: https://ikuokuo.github.io/sta... ,代码见: https://github.com/ikuokuo/st... 。

概念

首先,ui 是由 state 通过 fn 生成:

ui = fn(state)

在 React 里, fn 即组件,按照本人的 state 渲染。

如果 state 是共享的,一处状态更新,多处组件响应呢?这时就能够用 MobX 了。

MobX 数据流向如下:

      ui    ↙    ↖action → state

ui 触发 action,更新 state,重绘 ui。留神是单向的。

理解更多,请浏览 MobX 宗旨 。这里讲下实现时的次要步骤:

  • 定义数据存储类 Data Store

    • 成员属性为 state,成员函数为 action
    • mobx 标记为 observable
  • 定义 Stores Provider

    • 形式一 React.ContextcreateContext 包装 Store 实例,ui useContext 应用
    • 形式二 mobx-react.Provider:间接包装 Store 实例,提供给 Providerui inject 应用
  • 实现 ui 组件

    • mobx 标记为 observer
    • 获取 stores,间接援用 state
    • 若要更新 state,间接调用 action

我的项目构造上就是多个 stores 目录,定义各类 storestate action,异步操作也很简略。理解更多,请浏览:

  • 定义数据存储
  • 异步 actions

筹备

React App

yarn create react-app start-react --template typescriptcd start-react

React Router

路由库,以便导航样例。

yarn add react-router-dom

Antd

组件库,以便布局 UI。

yarn add antd @ant-design/icons

高级配置,

yarn add @craco/craco -Dyarn add craco-less

craco.config.js 配置了深色主题:

const path = require('path');const CracoLessPlugin = require('craco-less');const { getThemeVariables } = require('antd/dist/theme');module.exports = {  plugins: [    {      plugin: CracoLessPlugin,      options: {        lessLoaderOptions: {          lessOptions: {            modifyVars: getThemeVariables({              dark: true,              // compact: true,            }),            javascriptEnabled: true,          },        },      },    },  ],  webpack: {    alias: { '@': path.resolve(__dirname, './src') },  },};

ESLint

VSCode 装置 ESLint Prettier 扩大。初始化 eslint

$ npx eslint --init✔ How would you like to use ESLint? · style✔ What type of modules does your project use? · esm✔ Which framework does your project use? · react✔ Does your project use TypeScript? · No / Yes✔ Where does your code run? · browser✔ How would you like to define a style for your project? · guide✔ Which style guide do you want to follow? · airbnb✔ What format do you want your config file to be in? · JavaScript

配置 .eslintrc.js .eslintignore .vscode/settings.json,详见代码。并于 package.json 增加:

"scripts": {  "lint": "eslint . --ext .js,.jsx,.ts,.tsx --ignore-pattern node_modules/"},

执行 yarn lint 通过, yarn start 运行。

到此, React Antd 利用就筹备好了。初始模板如下,可见首个提交:

MobX

yarn add mobx mobx-react

mobx-react 蕴含了 mobx-react-lite,所以不用装置了。

  • 如果只用 React.FC (HOOK) 时,用 mobx-react-lite 即可。
  • 如果要用 React.Component (Class) 时,用 mobx-react 才行。

mobx-react-lite 与 React.FC

定义 Data Stores

makeAutoObservable

定义数据存储模型后,于构造函数里调用 makeAutoObservable(this) 即可。

stores/Counter.ts:

import { makeAutoObservable } from 'mobx';class Counter {  count = 0;  constructor() {    makeAutoObservable(this);  }  increase() {    this.count += 1;  }  decrease() {    this.count -= 1;  }}export default Counter;

React.Context Stores

React.Context 能够很简略的传递 Stores

stores/index.ts:

import React from 'react';import Counter from './Counter';import Themes from './Themes';const stores = React.createContext({  counter: new Counter(),  themes: new Themes(),});export default stores;

创立一个 useStoresHook,简化调用。

hooks/useStores.ts:

import React from 'react';import stores from '../stores';const useStores = () => React.useContext(stores);export default useStores;

Pane 组件,应用 Stores

组件用 observer 包装,useStores 援用 stores

Pane.tsx:

import React from 'react';import { Row, Col, Button, Select } from 'antd';import { PlusOutlined, MinusOutlined } from '@ant-design/icons';import { observer } from 'mobx-react-lite';import useStores from './hooks/useStores';type PaneProps = React.HTMLProps<HTMLDivElement> & {  name?: string;}const Pane: React.FC<PaneProps> = ({ name, ...props }) => {  const stores = useStores();  return (    <div {...props}>      {name && <h2>{name}</h2>}      <Row align="middle">        <Col span="4">Count</Col>        <Col span="4">{stores.counter.count}</Col>        <Col>          <Button            type="text"            icon={<PlusOutlined />}            onClick={() => stores.counter.increase()}          />          <Button            type="text"            icon={<MinusOutlined />}            onClick={() => stores.counter.decrease()}          />        </Col>      </Row>      {/* ... */}    </div>  );};Pane.defaultProps = { name: undefined };export default observer(Pane);

mobx-react 与 React.Component

定义 Data Stores

makeObservable + decorators

装璜器在 MobX 6 中放弃了,但还可应用。

首先,启用装璜器语法。TypeScripttsconfig.json 里启用:

"experimentalDecorators": true,"useDefineForClassFields": true,

定义数据存储模型后,于构造函数里调用 makeObservable(this)。在 MobX 6 前不须要,但当初为了装璜器的兼容性必须调用。

stores/Counter.ts:

import { makeObservable, observable, action } from 'mobx';class Counter {  @observable count = 0;  constructor() {    makeObservable(this);  }  @action  increase() {    this.count += 1;  }  @action  decrease() {    this.count -= 1;  }}export default Counter;

Root Stores

组合多个 Stores

stores/index.ts:

import Counter from './Counter';import Themes from './Themes';export interface Stores {  counter: Counter;  themes: Themes;}const stores : Stores = {  counter: new Counter(),  themes: new Themes(),};export default stores;

父组件,提供 Stores

父组件增加 mobx-react.Provider,并且属性扩大 stores

index.tsx:

import React from 'react';import { Provider } from 'mobx-react';import stores from './stores';import Pane from './Pane';const MobXCLS: React.FC = () => (  <div>    <Provider {...stores}>      <h1>MobX with React.Component</h1>      <div style={{ display: 'flex' }}>        <Pane name="Pane 1" style={{ flex: 'auto' }} />        <Pane name="Pane 2" style={{ flex: 'auto' }} />      </div>    </Provider>  </div>);export default MobXCLS;

Pane 组件,注入 Stores

组件用 observer 装璜,同时 inject 注入 stores

Pane.tsx:

import React from 'react';import { Row, Col, Button, Select } from 'antd';import { PlusOutlined, MinusOutlined } from '@ant-design/icons';import { observer, inject } from 'mobx-react';import { Stores } from './stores';type PaneProps = React.HTMLProps<HTMLDivElement> & {  name?: string;};@inject('counter', 'themes')@observerclass Pane extends React.Component<PaneProps, unknown> {  get injected() {    return this.props as (PaneProps & Stores);  }  render() {    const { name, ...props } = this.props;    const { counter, themes } = this.injected;    return (      <div {...props}>        {name && <h2>{name}</h2>}        <Row align="middle">          <Col span="4">Count</Col>          <Col span="4">{counter.count}</Col>          <Col>            <Button              type="text"              icon={<PlusOutlined />}              onClick={() => counter.increase()}            />            <Button              type="text"              icon={<MinusOutlined />}              onClick={() => counter.decrease()}            />          </Col>        </Row>        <Row align="middle">          <Col span="4">Theme</Col>          <Col span="4">{themes.currentTheme}</Col>          <Col>            <Select              style={{ width: '60px' }}              value={themes.currentTheme}              showArrow={false}              onSelect={(v) => themes.setTheme(v)}            >              {themes.themes.map((t) => (                <Select.Option key={t} value={t}>                  {t}                </Select.Option>              ))}            </Select>          </Col>        </Row>      </div>    );  }}export default Pane;

最初

MobX 文档能够浏览一遍,理解有哪些内容。未波及的外围概念还有 Computeds, Reactions。

其中 MobX and React 一节,详解了于 React 中的用法及留神点,见:React 集成,React 优化。

GoCoding 集体实际的教训分享,可关注公众号!