element-ui設置級聯選擇器表單驗證

data(){
<el-form :model="ruleForm" :rules="rules" ref="ruleForm" label-width="100px" class="demo-ruleForm">

<el-form-item label="選擇分類" prop="sorts">
                        <el-cascader
                                     :options="options"
                                     change-on-select
                                     filterable
                                     v-model="ruleForm.sorts"
                                     clearable></el-cascader>
                    </el-form-item>

</el-form>

/*表單驗證*/
ruleForm: {
    sorts: '',
},
/*驗證規則*/
rules: {
    sorts: [
        {required: true, message: '請選擇分類', trigger: 'change'}
    ],
},

}