element-ui设置级联选择器表单验证

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

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

</el-form>

/*表单验证*/
ruleForm: {
    sorts: '',
},
/*验证规则*/
rules: {
    sorts: [
        {required: true, message: '请选择分类', trigger: 'change'}
    ],
},

}