React简单解释如何封装组件的demo

发布时间：2020-12-15 07:15:36 所属栏目：百科来源：网络整理

导读：!DOCTYPE htmlhtml head meta charset= "utf-8" titleReactjs in 40 /title style media= "screen" .like-btn { font-size: 50 px; } /style /head body div class = 'wrapper' /div /body script type = "text/javascript" /* Component */ class Component

<!DOCTYPE html>
<html>

  <head>
    <meta charset="utf-8">
    <title>Reactjs in 40 </title>
    <style media="screen">
      .like-btn { font-size: 50px; }
    </style>
  </head>

  <body>
    <div class='wrapper'></div>
  </body>

  <script type="text/javascript">
    /* Component */
    class Component {
      constructor (props = {}) {
        this.props = props
      }
      setState (state) {
        const oldEl = this.el
        this.state = state
        this.el = this.renderDOM()
        if (this.onStateChange) this.onStateChange(oldEl,this.el)
      }
      renderDOM () {
        this.el = createDOMFromString(this.render())
        if (this.onClick) {
          this.el.addEventListener('click',this.onClick.bind(this),false)
        }
        return this.el
      }
    }
    const createDOMFromString = (domString) => {
      const div = document.createElement('div')
      div.innerHTML = domString
      return div
    }
    const mount = (component,wrapper) => {
      wrapper.appendChild(component.renderDOM())
      component.onStateChange = (oldEl,newEl) => {
        wrapper.insertBefore(newEl,oldEl)
        wrapper.removeChild(oldEl)
      }
    }
    /* ========================================= */
    class LikeButton extends Component {
      constructor (props) {
        super(props)
        this.state = { isLiked: false }
      }
      onClick () {
        this.setState({
          isLiked: !this.state.isLiked
        })
      }
      render () {
        return `
          <button class='like-btn' style="background-color: ${this.props.bgColor}">
            <span class='like-text'>
              ${this.state.isLiked ? '取消' : '点赞'}
            </span>
            <span>??</span>
          </button>
        `
      }
    }
    class RedBlueButton extends Component {
      constructor (props) {
        super(props)
        this.state = {
          color: 'red'
        }
      }
      onClick () {
        this.setState({
          color: 'blue'
        })
      }
      render () {
        return `
          <div style='color: ${this.state.color};'>${this.state.color}</div>
        `
      }
    }
    const wrapper = document.querySelector('.wrapper')
    mount(new LikeButton({ bgColor: 'red' }),wrapper)
    mount(new LikeButton(),wrapper)
    mount(new RedBlueButton(),wrapper)
  </script>
</html>

文章链接：http://huziketang.com/books/react/lesson2

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!