<template>
  <el-row>
    <el-col :span="24">
      <el-row ref="headerMenu" class="header-menu">
        <el-col :span="24">
          <el-menu router mode="horizontal">
            <el-menu-item index="1" route="/global-overview">全局概览</el-menu-item>
            <el-menu-item index="2" route="/e-commerce-business">电商业务</el-menu-item>
            <el-menu-item index="3" route="/douniao-business">抖鸟业务</el-menu-item>
            <el-menu-item index="4" route="/administrative-business">行政业务</el-menu-item>
            <el-menu-item index="5" route="/admin">管理员入口</el-menu-item>
          </el-menu>
        </el-col>
      </el-row>

      <el-row ref="routerView">
        <router-view></router-view>
      </el-row>

    </el-col>
  </el-row>
</template>

<script>
export default {
  name: "home-page",
  mounted() {
    /**
     * when the component is hung, dynamically obtain the height of the header menu,
     * and set this value to router view as margin top
     */
    this.$refs.routerView.$el["style"].marginTop = `${this.$refs.headerMenu.$el["offsetHeight"]}px`;
  }
}
</script>

<style scoped>
.header-menu {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 999;
}

</style>