JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//unpkg.com/vue/dist/vue.js"></script>
<script src="//unpkg.com/element-ui/lib/index.js"></script>
<div id="app">
<template>
  <el-button plain @click="open">
    打开通知
  </el-button>
</template>
</div>

SCSS

@import url("//unpkg.com/element-ui/lib/theme-default/index.css");

Babel + JSX

var Main = {
    data() {
      return {
        alreadyExists: false
      }
    },
    methods: {
      open() {
        if (this.alreadyExists) return
        this.$notify({
          title: '提示',
          message: '同一时刻只能显示一条消息',
          duration: 1000,
          onClose: this.handleClose(false)
        })
        this.alreadyExists = true
      },

      handleClose(a) {
        this.alreadyExists = a;
      }
    }
  }
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app')