<template>
    <div class="app-container">
      <div class="filter-container">
        <el-checkbox-group v-model="checkboxVal">
          <el-checkbox label="apple">
            apple
          </el-checkbox>
          <el-checkbox label="banana">
            banana
          </el-checkbox>
          <el-checkbox label="orange">
            orange
          </el-checkbox>
        </el-checkbox-group>
      </div>
  
      <el-table :key="key" :data="tableData" border fit highlight-current-row style="width: 100%">
        <el-table-column prop="name" label="fruitName" width="180" />
        <el-table-column v-for="fruit in formThead" :key="fruit" :label="fruit">
          <template slot-scope="scope">
            {{ scope.row[fruit] }}
          </template>
        </el-table-column>
      </el-table>
    </div>
  </template>
  
  <script>
  const defaultFormThead = ['apple', 'banana']
  
  export default {
    data() {
      return {
        tableData: [
          {
            name: 'fruit-1',
            apple: 'apple-10',
            banana: 'banana-10',
            orange: 'orange-10'
          },
          {
            name: 'fruit-2',
            apple: 'apple-20',
            banana: 'banana-20',
            orange: 'orange-20'
          }
        ],
        key: 1, // table key
        formTheadOptions: ['apple', 'banana', 'orange'],
        checkboxVal: defaultFormThead, // checkboxVal
        formThead: defaultFormThead // 默认表头 Default header
      }
    },
    watch: {
      checkboxVal(valArr) {
        this.formThead = this.formTheadOptions.filter(i => valArr.indexOf(i) >= 0)
        this.key = this.key + 1// 为了保证table 每次都会重渲 In order to ensure the table will be re-rendered each time
      }
    }
  }
  </script>