About the implementation of Vue comment framework (implementation of parent component)

<!-- 文档结构区开始 -->
<template>
  <p id="comment" >
    <Userp @transferUser="getInput" ></Userp>
    <Commentp :List="List"></Commentp>
    <Pagep @transferUser="getPage" :totalCount="totalCount" :currentPage="currentPage"></Pagep>
  </p>
</template>
<!-- 文档结构区结束 -->

<!-- js 控制区开始 -->
<script>
//引入组件 commentInput、commentList、pagination
import Userp from &#39;./commentInput.vue&#39;
import Pagep from &#39;./pagination.vue&#39;
import Commentp from &#39;./commentList.vue&#39;

export default {
  //声明组件名
  name: &#39;comment&#39;,

  //包含实例可用组件的哈希表
  components: {
    Userp,
    Pagep,
    Commentp
  },

  //声明组件参数
  data() {
    return {
      totalCount: 0,
      currentPage: 1,
      pagesize: 3,
      totalData: [],
      List: [],
    }
  },

  methods: {
    //显示评论列表信息的方法
    getInput(msg) {
      //将评论信息保存到评论数组里
      this.totalData.push({ text: msg })
      //计算评论信息总条数长度
      this.totalCount = this.totalData.length

      //判断评论总数是否大于单页显示条数
      if (this.totalCount <= this.pagesize) {
       // 显示所有评论
       this.List = this.totalData
      } else {
       // 截取totalData中 this.totalCount - this.pagesize 后面的元素进行显示
       this.List = this.totalData.slice(this.totalCount - this.pagesize)
      }
      //点击评论按钮，默认跳转显示第一页内容
      this.currentPage = 1
      //评论列表倒序显示，即最新评论，显示在最上面
      this.List.reverse()

    },

    // 计算评论列表每一页的显示内容
    getPage(curr, size) {
      this.currentPage = curr

      if (this.totalCount <= this.pagesize) {
        //显示所有评论
        this.List = this.totalData
      } else {
        var start = this.totalCount - this.currentPage * this.pagesize
        if (start < 0) { start = 0 }
        // 截取totalData中 [start, start + this.pagesize] 位元素进行显示
        this.List = this.totalData.slice(start, start + this.pagesize)
      }
      //评论列表倒序显示，即最新评论，显示在最上面
      this.List.reverse()
    }
  },
}
</script>
<!-- js 控制区结束 -->