<template>
    <div class="tab-container">
      <el-tag>mounted times ：{{ createdTimes }}</el-tag>
      <el-alert :closable="false" style="width:200px;display:inline-block;vertical-align: middle;margin-left:30px;" title="Tab with keep-alive" type="success" />
      <el-tabs v-model="activeName" style="margin-top:15px;" type="border-card">
        <el-tab-pane v-for="item in tabMapOptions" :key="item.key" :label="item.label" :name="item.key">
          <keep-alive>
            <tab-pane v-if="activeName==item.key" :type="item.key" @create="showCreatedTimes" />
          </keep-alive>
        </el-tab-pane>
      </el-tabs>
    </div>
  </template>
  
  <script>
  import tabPane from './components/TabPane'
  
  export default {
    name: 'Tab',
    components: { tabPane },
    data() {
      return {
        tabMapOptions: [
          { label: 'China', key: 'CN' },
          { label: 'USA', key: 'US' },
          { label: 'Japan', key: 'JP' },
          { label: 'Eurozone', key: 'EU' }
        ],
        activeName: 'CN',
        createdTimes: 0
      }
    },
    watch: {
      activeName(val) {
        this.$router.push(`${this.$route.path}?tab=${val}`)
      }
    },
    created() {
      // init the default selected tab
      const tab = this.$route.query.tab
      if (tab) {
        this.activeName = tab
      }
    },
    methods: {
      showCreatedTimes() {
        this.createdTimes = this.createdTimes + 1
      }
    }
  }
  </script>
  
  <style scoped>
    .tab-container {
      margin: 30px;
    }
  </style>