详解react-refetch的使用小例子

所属分类：网络编程 / JavaScript 阅读数： 1325

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使用react-refetch来简化api获取数据的代码

const List = ({data: gists}) => {
 return (
  <ul>
   {gists.map(gist => (
    <li key={gist.id}>{gist.description}</li>
   ))}
  </ul>
 )
}

const withData = url => Part => {
 return class extends Component {
  state = {data: []}

  componentDidMount() {
   fetch(url)
    .then(response => response.json ? response.json() : response)
    .then(data => this.setState({data}))
  }

  render() {
   return <Part {...this.state} {...this.props} />
  }
 }
}

const ListWithGists = withData('https://api.github.com/users/gaearon/gists')(List)

上面的代码，我们将api获取数据的逻辑用高阶组件抽离出来，下面我们再用react-refetch来简化上面的异步代码

import { connect as refetchConnect } from 'react-refetch'

const List = ({gists}) => {
 if (gists.pending) {
  return <div>loading...</div>
 } else if (gists.rejected) {
  return <div>{gists.reason}</div>
 } else if (gists.fulfilled) {
  return (
   gists.fulfilled && <ul>
    {gists.value.map(gist => (
     <li key={gist.id}>{gist.description}</li>
    ))}
   </ul>
  )
 }
}

const ListWithGists = refetchConnect(() => ({gists: `https://api.github.com/users/gaearon/gists`}))(List)

瞬间清爽多了，顺便利用react-refetch提供的属性，顺便把loading逻辑也添加了

分离列表和项目的职责

很明显，List组件是一个渲染列表的组件，他的职责就是渲染列表，但是我们在这里也处理了单个Item的逻辑，我们可以将其进行职责分离,List只做列表染，而Gist也只渲染自身

const Gist = ({description}) => (
 <li>
  {description}
 </li>
)

const List = ({gists}) => {
 if (gists.pending) {
  return <div>loading...</div>
 } else if (gists.rejected) {
  return <div>{gists.reason}</div>
 } else if (gists.fulfilled) {
  return (
   gists.fulfilled && <ul>
    {gists.value.map(gist => <Gist key={gist.id} {...gist} />)}
   </ul>
  )
 }
}

使用react-refetch来给Gist添加功能

react-refetch的connect方法接收一个函数作为参数，这个函数返回一个对象，如果结果对象的值是一个字符串，那么获取prop后，会对这个字符串发起请求，但是如果值是一个函数，那么不会立即执行，而是会传递给组件，以便后续使用

值为字符串

const connectWithStar = refetchConnect(() => ({gists: `https://api.github.com/users/gaearon/gists`}))

值为函数

const connectWithStar = refetchConnect(({id}) => ({
 star: () => ({
  starResponse: {
   url: `https://api.github.com/gists/${id}/star?${token}`,
   method: 'PUT'
  }
 })
}))

const Gist = ({description, star}) => (
 <li>
  {description}
  <button onClick={star}>+1</button>
 </li>
)

加工Gist组件，star函数会被传递给Gist的prop，然后就可以在Gist里面使用了