在react中用裝飾器來裝飾connect

假設咱們在react中有以下header組件：

import React, { PureComponent } from 'react';
import { connect } from 'react-redux';
import actions from './actions';
class Header extends PureComponent{
  render(){
    return (
      <div>這是個組件</div>
    )
  }
}

const mapStateToProps = state => ({
  todos:state.todos
})

const mapDispatchToProps = dispatch => ({
  setTodos:value=>dispatch(actions.setTodos(value))
})

export default connect(mapStateToProps,mapDispatchToProps)(Header)

咱們在寫react組件時結合redux要定義mapStateToProps和mapDispatchToProps兩個返回對象的純函數以便交給connect去包裹使用 具體connect使用查看connect

這裏咱們就能夠用裝飾器(Decorator)來改寫下:

import React, { PureComponent } from 'react';
import { connect } from 'react-redux';
import actions from './actions';

@connect(
  state=>({
    todos:state.todos
  }),
  dispatch=>({
    setTodos:value=>dispatch(actions.setTodos(value))
  })
)
class Header extends PureComponent{
  render(){
    return (
      <div>這是個組件</div>
    )
  }
}

export default Header

如此，改造完成，代碼看上去也比改造前的乾淨整潔了

可是因爲裝飾器的兼容性問題咱們須要使用babel來轉換

// 安裝babel插件
yarn add @babel/plugin-proposal-decorators

修改package.json下的babel

"babel": {
  "presets": [
    "react-app"
  ],
  "plugins": [
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ]
  ]
},

最後一步
根目錄下新建jsconfig.json解決編輯器報錯問題

{
  "compilerOptions": {
    "experimentalDecorators": true
  }
}

而後就能夠愉快的coding了