Vue 全局loading组件知识点分享

import './loading.css'
 let Loading = {}
// 避免重复install，设立flag
Loading.installed = false
Loading.install = function (Vue) {
 if (Loading.installed) return
 Vue.prototype.$loading = {}
 Vue.prototype.$loading.show = () => {
 // 如果页面有loading则不继续执行
 if (document.querySelector('#vue-loading')) return
 // 1、创建构造器，定义loading模板
 let LoadingTip = Vue.extend({
  template: `<div id="vue-loading">
     <div class="loader"></div>
     </div>`
 })
 // 2、创建实例，挂载到文档以后的地方
 let tpl = new LoadingTip().$mount().$el
 // 3、把创建的实例添加到body中
 document.body.appendChild(tpl)
 // 阻止遮罩滑动
 document.querySelector('#vue-loading').addEventListener('touchmove', function (e) {
  e.stopPropagation()
  e.preventDefault()
 })
 Loading.installed = true
 }
 Vue.prototype.$loading.hide = () => {
 let tpl = document.querySelector('#vue-loading')
 document.body.removeChild(tpl)
 }
}
export default Loading

#vue-loading {
 width: 100%;
 height: 100%;
 position: absolute;
 left: 0;
 top: 0
}
.loader {
 position: relative;
 width: 2.5em;
 height: 2.5em;
 transform: rotate(165deg);
}
.loader:before, .loader:after {
 content: '';
 position: absolute;
 top: 50%;
 left: 50%;
 display: block;
 width: 0.5em;
 height: 0.5em;
 border-radius: 0.25em;
 transform: translate(-50%, -50%);
}
.loader:before {
 animation: before 2s infinite;
}
.loader:after {
 animation: after 2s infinite;
}
@keyframes before {
 0% {
 width: 0.5em;
 box-shadow: 1em -0.5em rgba(225, 20, 98, 0.75), -1em 0.5em rgba(111, 202, 220, 0.75);
 }
 35% {
 width: 2.5em;
 box-shadow: 0 -0.5em rgba(225, 20, 98, 0.75), 0 0.5em rgba(111, 202, 220, 0.75);
 }
 70% {
 width: 0.5em;
 box-shadow: -1em -0.5em rgba(225, 20, 98, 0.75), 1em 0.5em rgba(111, 202, 220, 0.75);
 }
 100% {
 box-shadow: 1em -0.5em rgba(225, 20, 98, 0.75), -1em 0.5em rgba(111, 202, 220, 0.75);
 }
}
@keyframes after {
 0% {
 height: 0.5em;
 box-shadow: 0.5em 1em rgba(61, 184, 143, 0.75), -0.5em -1em rgba(233, 169, 32, 0.75);
 }
 35% {
 height: 2.5em;
 box-shadow: 0.5em 0 rgba(61, 184, 143, 0.75), -0.5em 0 rgba(233, 169, 32, 0.75);
 }
 70% {
 height: 0.5em;
 box-shadow: 0.5em -1em rgba(61, 184, 143, 0.75), -0.5em 1em rgba(233, 169, 32, 0.75);
 }
 100% {
 box-shadow: 0.5em 1em rgba(61, 184, 143, 0.75), -0.5em -1em rgba(233, 169, 32, 0.75);
 }
}
/**
 * Attempt to center the whole thing!
 */
html,
body {
 height: 100%;
}
.loader {
 position: absolute;
 top: calc(50% - 1.25em);
 left: calc(50% - 1.25em);
}