Vue.JS实现垂直方向展开、收缩不定高度模块的JS组件

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需求分析：

如图，有很多高度不固定的模块（图中只显示两个，本人项目有十三个），点击模块标题展开相应的模块，再次点击此模块匿藏，如何实现此需求并实现复用？

点击红框前：

这里写图片描述

点击后：

这里写图片描述

难点分析:

模块高度不固定。比如，本人一开始想到的方法如下：

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    .box{
      height:500px;
      background-color:black; 
       overflow: hidden;            
    }
    .mybox-leave-active,.mybox-enter-active{
      transition: all 1s ease; 
    }
    .mybox-leave-active,.mybox-enter{
      height:0px !important;
    }
    .mybox-leave,.mybox-enter-active{
      height: 500px;
    }
  </style>
</head>
<body>
<div id="box">
  <transition name="mybox">
    <div class="box" v-show="boxshow"></div>
  </transition>
  <button @click="togglebox">按钮</button>
</div>
</body>
<script src="../bower_components/vue/dist/vue.js"></script>
<script>
  new Vue({
    el:'#box',
    data:{
      boxshow:false
    },
    methods:{

      togglebox:function(){
        this.boxshow = !this.boxshow;
      }
    }   
  });
</script>
</html>

这种方法确实可以实现点击展开，再次点击收缩的需求，但是有一个明显的缺点：限定了容器的高度，也就是每个模块都需要固定高度，并不适用于需求场景。

解决方案：

1、实现一个函数式组件

本人命名为vertical-toggle.js
// Created by xiaoqiang on 17/04/2018.
const elTransition = '0.3s height ease-in-out, 0.3s padding-top ease-in-out, 0.3s padding-bottom ease-in-out'
const Transition = {
 'before-enter' (el) {
  el.style.transition = elTransition
  if (!el.dataset) el.dataset = {}
  el.dataset.oldPaddingTop = el.style.paddingTop
  el.dataset.oldPaddingBottom = el.style.paddingBottom
  el.style.height = 0
  el.style.paddingTop = 0
  el.style.paddingBottom = 0
 },
 'enter' (el) {
  el.dataset.oldOverflow = el.style.overflow
  if (el.scrollHeight !== 0) {
   el.style.height = el.scrollHeight + 'px'
   el.style.paddingTop = el.dataset.oldPaddingTop
   el.style.paddingBottom = el.dataset.oldPaddingBottom
  } else {
   el.style.height = ''
   el.style.paddingTop = el.dataset.oldPaddingTop
   el.style.paddingBottom = el.dataset.oldPaddingBottom
  }
  el.style.overflow = 'hidden'
 },
 'after-enter' (el) {
  el.style.transition = ''
  el.style.height = ''
  el.style.overflow = el.dataset.oldOverflow
 },
 'before-leave' (el) {
  if (!el.dataset) el.dataset = {}
  el.dataset.oldPaddingTop = el.style.paddingTop
  el.dataset.oldPaddingBottom = el.style.paddingBottom
  el.dataset.oldOverflow = el.style.overflow
  el.style.height = el.scrollHeight + 'px'
  el.style.overflow = 'hidden'
 },
 'leave' (el) {
  if (el.scrollHeight !== 0) {
   el.style.transition = elTransition
   el.style.height = 0
   el.style.paddingTop = 0
   el.style.paddingBottom = 0
  }
 },
 'after-leave' (el) {
  el.style.transition = ''
  el.style.height = ''
  el.style.overflow = el.dataset.oldOverflow
  el.style.paddingTop = el.dataset.oldPaddingTop
  el.style.paddingBottom = el.dataset.oldPaddingBottom
 }
}
export default {
 name: 'VerticalToggle',
 functional: true,
 render (h, { children }) {
  const data = {
   on: Transition
  }
  return h('transition', data, children)
 }
}

2、引用此组件

这里写图片描述