refetch的使用小例子

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

connectWithStar(Gist)