How to use vue.js to realize that the pop-up box only plays once

<template>
 <p v-if="isShow"> <!--最外层背景-->
  <p class="popup_container"> <!--居中的容器-->
   <img @click="noPopup" src="delete.png" alt=""> <!--关闭弹框-->
   <p class="popup_text"> <!--内容部分-->
    Lorem ipsum dolor sit amet, consectetur adipisicing elit. At, atque ea eveniet laudantium magni, maiores nam nihil non numquam odio pariatur perferendis placeat quas quasi sit soluta, sunt ullam voluptatibus.  
   </p>
  </p>
 </p>
</template>
<script>
 export default {
  data(){
   return{
    isShow: true,
   }
  },
  created(){
   if (this.getCookie(&#39;popped&#39;) == &#39;&#39;){ //cookie 中没有 popped 则赋给他一个值（此时弹框显示）
    document.cookie = "popped = yes";
   }else{
    this.isShow = false; //若cookie 中已经有 popped 值，则弹框再不会显示
   }
  },
  methods: {
   noPopup(){
    this.isShow = false;
   },
   getCookie(Name) { //cookie
    var search = Name + "=";
    var returnValue = "";
    if (document.cookie.length > 0) {
     var offset = document.cookie.indexOf(search);
     if (offset !== -1) {
      offset += search.length;
      var end = document.cookie.indexOf(";", offset);
      if (end == -1){
       end = document.cookie.length;
      }
      returnValue = decodeURIComponent(document.cookie.substring(offset, end));
     }
    }
    return returnValue;
   },
  },
 }
</script>
<style scoped>
  /*样式部分*/
</style>