vue中使用element-ui导航菜单对接后台数据

<template>
    <div class="sidebar">
        <el-menu
            class="sidebar-el-menu"
            :default-active="onRoutes"
            background-color="#324157"
            text-color="#bfcbd9"
            active-text-color="#20a0ff"
            unique-opened
            router>
        // 循环items菜单数据
            <template v-for="item in items">
            // v-if="item.subs" 判断这一项数据是否有子项菜单
                <template v-if="item.subs">
                    <el-submenu :index="item.index" :key="item.index">
                        <template slot="title">
                            <i :class="item.icon"></i>
                            <span slot="title">{{ item.title }}</span>
                        </template>
                        <template v-for="subItem in item.subs">
                            <el-submenu
                                v-if="subItem.subs"
                                :index="subItem.index"
                                :key="subItem.index">
                                <template slot="title">{{ subItem.title }}</template>
                                <el-menu-item
                                    v-for="(threeItem,i) in subItem.subs"
                                    :key="i"
                                    :index="threeItem.index">{{ threeItem.title }}</el-menu-item>
                            </el-submenu>
                            <el-menu-item
                                v-else
                                :index="subItem.index"
                                :key="subItem.index">{{ subItem.title }}</el-menu-item>
                        </template>
                    </el-submenu>
                </template>
                // 一级菜单
                <template v-else>
                    <el-menu-item :index="item.index" :key="item.index">
                        <i :class="item.icon"></i>
                        <span slot="title">{{ item.title }}</span>
                    </el-menu-item>
                </template>
            </template>
        </el-menu>
    </div>
</template>