jquery select操作和联动操作

 (function(){
     //select操作
     $.fn.loadSelect = function(opt){
         opt = $.extend({}, {
             required:false,//为真则添加<option value="" selected="selected">required值</option>
             nodata:null,//子级无数据时 select 的状态。可设置为："none"(display隐藏) | "hidden"(visibility隐藏) | 无
             data:[],
             loadCall:function(){}
         }, opt);
         var d = {}, callback = function(data, s){
             var html = '';
             $.each(data||[], function(i,n){
                 d = n.id ? n : {
                     id:i,
                     text:n
                 };
                 html += '<option value="'+d.id+'"'+((opt.def != undefined && (opt.def == d.id || opt.def == d.text)) ? ' selected="selected"' : '')+'>'+d.text+'</option>';
             });
             s.html(r+html);
             (r || html) && s.trigger('change');
             switch(opt.nodata){
                 case 'none':
                     html === '' ? s.hide() : s.show();
                     break;
                 case 'hidden':
                     s.css('visibility', html === '' ? 'hidden' : 'visible');
                     break;
             }
             $.isFunction(opt.loadCall) && opt.loadCall.call(s);
         }, r = opt.required ? '<option value="">'+($.type(opt.required) == 'string' ? opt.required : '-请选择-')+'</option>' : '';
         return this.each(function(){
             var s = $(this);
             if(s.is('select')){
                 if(typeof(opt.data) === 'string'){
                     s.empty();
                     $.getJSON(opt.data, function(json){
                         callback(json, s);
                     });
                 }else{
                     callback(opt.data, s);
                 }
             }
         });
     },
     //select联动
     $.fn.linkage = function(opt){
         opt = $.extend({}, {
             build:true,//自动创建不存在的?
             selects:['#city', '#area'],//子集select,按顺序,jquery选择器(.#)
             seldef:[],//默认值,1以后和上项对应,可是id或者text
             required:true,
             nodata:'',
             url:'/company/getCity.html?id={$id}',//子数据,string,{$id} or {$text}页码信息
             data:[],//父级的数据
             def:0//父级默认值
         }, opt);
         var mkSelect = function(i){
             var n = child[i], nN = $(n);
             if( i && n && opt.build && nN.length === 0 ){
                 var sn = n.substr(1), ci = n.substr(0, 1) == '#' ? 'id="'+sn+'"' : 'class="'+sn+'"';
                 nN = $(child[i-1]).after('<select name="'+sn+'" '+ci+'></select>').next();
             }

             !nN.data('linkage') && nN.change(function(){
                 mkSelect(i+1).loadSelect({
                     data: this.value ? opt.url.sprintf({
                         id: this.value,
                         text: this.selectedIndex >= 0 ? this.options[this.selectedIndex].text : ''
                     }) : [],
                     nodata:opt.nodata,
                     required:opt.required,
                     def:opt.seldef[i]||''
                 });
             }).data('linkage', true);

             return nN;
         }, child = opt.selects||[];
         child.unshift(this);
         var s = mkSelect(0);
         opt.data.length && s.loadSelect({
             data:opt.data,
             def:opt.def
         });
         return this;
     },
     //jquery.printf
     String.prototype.sprintf = function(data, def) {
         return this.replace(/(?:\{\$)([\w\d\-\_]+)(?:\})/g, function() {
             return data[arguments[1]]||def||'';
         });
     }
 });

示例:

 <div class="jumbotron">
     <h1>联动测试</h1>
     <select name="" id="addr_prv"></select>
 </div>
 <script type="text/javascript">
     In.ready(function(){
         $('#addr_prv').linkage({data:'/company/getCity.html',seldef:[37,567]});
     });
 </script>