js中select动态渲染实现二级联动的代码

<div class="layui-form-item layui-row layui-col-space5">
 <div class="layui-col-md6">
 <label class="layui-form-label">一级分类</label>
 <div class="layui-input-block layui-select-block">
 <select name="oaalFtype" id="oaalFtype" lay-filter="oaalFtype"></select>
 </div>
 </div>
 <div class="layui-col-md6">
 <label class="layui-form-label">二级分类</label>
 <div class="layui-input-block layui-select-block">
 <select name="oaalStype" id="oaalStype" lay-filter="oaalStype"></select>
 </div>
 </div>
 </div>

layui.use(['element', 'form', 'layer'], function(){
var $ = layui.jquery
,element = layui.element
,form = layui.form
,layer = layui.layer;
//初始化下拉框
function initSelect(id,url){
$.post(url,function(result){
var data = result.data;
var arr = new Array();
arr.push("<option value=''>请选择</option>");
$.each(data, function(i,item){
var t = item.text, v = item.value, option = "<option value='"+v+"'>"+t+"</option>";
arr.push(option);
})
$("#"+id).empty();
$("#"+id).append(arr.join(""));
form.render('select');
})
}
//表单提交
form.on('submit(save)',function(data){
var options = {
 url: "${mbase}/saveOaAssetlib.do",
 type: "POST",
 success: function (data) {
 if(data.success){
 layer.alert(data.messages[0],{icon: 1},function(){
 window.close();
 window.opener.location.reload();
 });
 }
 }
 };
 $("#formData").ajaxSubmit(options);
})
//一级分类
var oaalFtype = "${base}/risen/pub/dictCombo.action?uuid=/DICT/OA/ASSETLIB/FTYPE&TYPE=jsn_grid";
initSelect("oaalFtype",oaalFtype);
//批次
var oaalBatch = "${base}/risen/pub/dictCombo.action?uuid=/DICT/OA/ASSETLIB/BATCH&TYPE=jsn_grid";
initSelect("oaalBatch",oaalBatch);
//监控一级分类
form.on('select(oaalFtype)', function(data){//2级联动
//二级分类初始化
var oaalStype = "${base}/risen/pub/dictCombo.action?uuid=/DICT/OA/ASSETLIB/FTYPE/"+encodeURI(data.value)+"&TYPE=jsn_grid";
initSelect("oaalStype",oaalStype);
}); 
});