创建一个抽象逻辑的组件（从现有代码）

Question

我创建这个代码：

import React from 'react'
import { range } from 'lodash'

const DIV_NUMBER = 5

export default class App extends React.Component {
  constructor(props) {
    super(props)
    this.divs = []
  }

  handleScroll = divIdx => () => {
    const divRef = this.divs[divIdx]
    const left = divRef.scrollLeft
    const top = divRef.scrollTop
    this.divs.forEach(div => (div.scrollLeft = left))
    this.divs.forEach(div => (div.scrollTop = top))
  }

  render() {
    return (
      <div style={{ border: '1px solid tomato' }}>
        {range(DIV_NUMBER).map(i => {
          return (
            <div
              key={i}
              ref={divElem => (this.divs[i] = divElem)}
              onScroll={this.handleScroll(i)}
              style={{
                width: 300,
                height: 100,
                margin: '2px',
                overflow: 'auto',
                border: '1px solid black',
              }}
            >
              <div
                style={{
                  width: 500,
                  height: 400,
                }}
              >
                Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor
                incididunt ut labore et dolore magna aliqua. Scelerisque eu ultrices vitae auctor eu
                augue ut lectus. In fermentum et sollicitudin ac orci. Velit sed ullamcorper morbi
                tincidunt ornare. Auctor eu augue ut lectus arcu bibendum. Non nisi est sit amet.
                Facilisis magna etiam tempor orci eu lobortis. Et tortor at risus viverra adipiscing
                at in tellus integer. Lacus luctus accumsan tortor posuere ac ut consequat semper
                viverra. Fermentum dui faucibus in ornare quam viverra orci sagittis. Porttitor eget
                dolor morbi non. Pulvinar pellentesque habitant morbi tristique senectus et.
                Tincidunt eget nullam non nisi est sit amet facilisis magna. Purus semper eget duis
                at tellus at urna condimentum. Ipsum dolor sit amet consectetur adipiscing. Sit amet
                aliquam id diam maecenas ultricies mi eget mauris. Faucibus scelerisque eleifend
                donec pretium vulputate sapien nec sagittis. Tristique senectus et netus et
                malesuada fames ac turpis. Egestas integer eget aliquet nibh. Enim ut tellus
                elementum sagittis vitae. Urna condimentum mattis pellentesque id nibh tortor id
                aliquet. Magna eget est lorem ipsum dolor. Felis imperdiet proin fermentum leo vel
                orci porta. Eget egestas purus viverra accumsan in nisl nisi. Adipiscing commodo
                elit at imperdiet. Facilisis magna etiam tempor orci eu lobortis. Volutpat est velit
                egestas dui id ornare arcu odio. Praesent elementum facilisis leo vel fringilla.
                Laoreet non curabitur gravida arcu ac tortor dignissim convallis aenean. Sodales ut
                etiam sit amet nisl. Turpis massa tincidunt dui ut ornare. Viverra mauris in aliquam
                sem fringilla ut morbi tincidunt augue.
              </div>
            </div>
          )
        })}
      </div>
    )
  }
}

有用。它创建5个div元素，滚动其中一个，所有div滚动togheter。我使用React引用来做到这一点。

我现在要做的是创建一个抽象这个逻辑的组件。

我想象这样的事情：

<ScrollDivs>
  {range(DIV_NUMBER).map(i => {
    return (
      <div
        key={i}
        style={{
          width: 500,
          height: 400,
        }}
      >
        all the text...
      </div>
    )
  })}
</ScrollDivs>

所以一个处理逻辑的魔法组件ScrollDivs。谁使用这个组件不必担心它是如何完成的，他只需要包装想要能够在这个组件内滚动的div。

我能怎么做？我不知道从哪里开始。

任何帮助都很感激

Answer 1

React.Children.map可以帮助你迭代props.children和React.cloneElement可以帮助传递给儿童的新道具：

export default class ScrollDivsSync extends React.Component {
  divs = [];

  handleScroll = e => {
    const { scrollTop, scrollLeft } = e.target;
    this.divs.forEach(div => {
      div.scrollLeft = scrollLeft;
      div.scrollTop = scrollTop;
    });
  };

  render() {
    const { children } = this.props;

    let i = 0;
    const enhancedChildren = React.Children.map(children, child =>
      React.cloneElement(child, {
        onScroll: this.handleScroll,
        ref: divElem => (this.divs[i++] = divElem)
      })
    );

    return enhancedChildren;
  }
}

这是一个带the example的CodeSandbox