如何操作vue input输入校验字母数字组合且长度小于30

<Input v-model="form.glhm" placeholder="请输入关联交易号" style="width:240px" @on-blur="validateJyh(form.glhm)"></Input> 
validateJyh(glhm){//校验关联交易号 
    var reg = /^[A-Za-z0-9]{1,30}$/; 
    if(!reg.test(glhm)){ 
     this.$Message.error("请输入字母或数字组成的交易关联号"); 
     this.form.glhm = ''; 
    } 
   },

var tr = document.getElementById("Id1"), // 取得ID为Id1的tr对象
 inps = tr.getElementsByTagName('input'); // 从tr 对象中获取所有input对象
for(var i = 0, len = inps.length; i < len; i++) {
 inps[i].value = ''; // 将每一个input的value置为空
}
document.getElementById("t").getElementsByTagName('input')[0].value='';

<el-input
@change="checkNo(searchForm.msel.mselTotalConsumTimes)"
type = "text"
onkeypress="return event.keyCode>=48&&event.keyCode<=57"
size="small"
:maxlength="6"
style="width: 120px"
v-model="searchForm.msel.mselTotalConsumTimes"></el-input>
 次
</el-col>
checkNo(value){
let reg = /^[1-9]\d*$/;
if (value) {
if (value >
999999 || new
RegExp(reg).test(value) ==
false) {
setTimeout(() 
=> {
this.searchForm.msel.mselTotalConsumTimes ='';
   }, 500);
}
}
},