vue+elementui表单数组对象深层嵌套之自定义验证规则

需求场景：在Vue+Elementui项目中，需要在表单的循环数组中，对某一深层嵌套的对象属性制定自定义校验规则。

<template>
    <div>
        <el-form :model="form" ref="form" label-width="110px">
            <div v-for="(item,index) in form.list" :key="index">
                <el-col :xs="24"
                      :sm="24"
                      :md="12"
                      :lg="4">
                    <el-form-item label="默认值" :prop="`list.${index}.state`"           :rules="{ required:true, validator: validateState, trigger: 'blur', index:index }">
                      <el-input v-model.number="item.state"></el-input>
                    </el-form-item>
                </el-col>
                <el-col :xs="24"
                        :sm="24"
                        :md="11"
                        :lg="5">
                    <el-form-item label="是否可调">
                      <el-switch active-text="是" inactive-text="否" v-            model="item.adjust.isAdjust">
                      </el-switch>
                    </el-form-item>
                </el-col>
                <el-col :xs="24"
                      :sm="24"
                      :md="12"
                      :lg="8"
                      v-show="item.adjust.isAdjust">
                    <el-form-item label="范围调节" required>
                      <el-col :span="11">
                        <el-form-item :prop="`list.${index}.adjust.min`" :rules="{ required:true, validator: validateMin, trigger: 'blur', index:index }">
                          <el-input v-model.number="item.adjust.min"
                                placeholder="最小值">
                          </el-input>
                        </el-form-item>
                      </el-col>
                      <el-col :span="1">
                       <div style="text-align:center;">至</div>                                        
                      </el-col>
                      <el-col :span="11">
                        <el-form-item :prop="`list.${index}.adjust.max`" :rules="{ required:true, validator: validateMax, trigger: 'blur', index:index }">
                          <el-input v-model.number="item.adjust.max"
                                placeholder="最大值">
                          </el-input>
                        </el-form-item>
                      </el-col>
                    </el-form-item>
                </el-col>
            </div>
        </el-form>
    </div>
</template>
<script>
export default{
    data(){
        return{
            // 此处略过。。。挪用上文
        }
    },
    methods:{
        isEmpty(arg) { 
            if(typeof arg === 'undefined' || arg === null || arg === ''){
                return true
            }
            return false
        },
        validateState(rule,value,callback){
            let min = this.form.list[rule.index].adjust.min
            let max = this.form.list[rule.index].adjust.max
            if(this.isEmpty(value)) {
                return callback(new Error('参数不得为空')))
            }
            if(!this.isEmpty(min) && !this.isEmpty(max) && parseInt(value) <     
parseInt(min)) {
                return callback(new Error('不得小于最小值')))
            }
            if(!this.isEmpty(min) && !this.isEmpty(max) && parseInt(value) > parseInt(max)) {
                return callback(new Error('不得大于最大值'))
            }
            return callback()
        },
    }
}
</script>