Vue2.x中el-table树形表格如何实现父子节点复选框联动及分页保留选择状态？

<template>
  <div id="app">
    <el-table
      :data="tableData"
      ref="multipleTable"
      row-key="id"
      style="width: 100%"
      tooltip-effect="dark"
    >
      <el-table-column reserve-selection type="selection" width="55"></el-table-column>
      <el-table-column label="日期" width="120">
        <template slot-scope="scope">{{ scope.row.date }}</template>
      </el-table-column>
      <el-table-column label="姓名" prop="name" width="120"></el-table-column>
      <el-table-column label="地址" prop="address" show-overflow-tooltip></el-table-column>
    </el-table>
    <div style="margin-top: 20px">
      <el-button @click="setPage(1)">第一页</el-button>
      <el-button @click="setPage(2)">第二页</el-button>
    </div>
  </div>
</template>

<script>
const fetchData = (page) => {
  return new Promise((resolve) => {
    setTimeout(() => {
      const page1Data = [
        { id: "1", date: "2016-05-03", name: "王小虎", address: "上海市普陀区金沙江路 1518 弄" },
        { id: "2", date: "2016-05-02", name: "王小虎", address: "上海市普陀区金沙江路 1518 弄" },
      ];
      const page2Data = [
        { id: "3", date: "2016-05-03", name: "雷军", address: "上海市普陀区金沙江路 1518 弄" },
        { id: "4", date: "2016-05-02", name: "雷军", address: "上海市普陀区金沙江路 1518 弄" },
      ];

      if (page === 1) {
        resolve(page1Data);
      }
      if (page === 2) {
        resolve(page2Data);
      }
    }, 1000);
  });
};

export default {
  name: "App",
  data() {
    return {
      page: 1,
      tableData: [],
      multipleSelection: [],
    };
  },

  methods: {
    setPage(page) {
      this.page = page;
    },
    async getTableData(page) {
      const data = await fetchData(page);
      this.tableData = data;
    },
    handleSelectionChange(val) {
      console.log("val", val); //在此处添加父子节点联动逻辑
    },
  },
  watch: {
    page: {
      immediate: true,
      handler(val) {
        this.getTableData(val);
      },
    },
  },
};
</script>