js基于json的级联下拉框

级联下拉列表是项目中常用到的。比如省市县，比如企业性质等，做成一个js通用组件，

在静态页出来后可以直接插入，将数据和html静态页做一个解耦。

贴出来抛砖引玉吧。

/**
 * @author sunfengjia edit
 * 说明：         使用json数据格式，生成N级下拉框
 * params:
 * data:          json对象
 * select:      级联下拉框名称

    调用eg：
       var comboselect = ComboSelectFactory(data, 'p1', 'p2', 'p3', 'p4');

    idKey: 数据的id字段名
    textKey: 数据的显示文本字段名
    parentIdKey: 数据的父节点字段名
    topParentValue:最顶层的值
    设定下拉列表 idKey,textKey,parentIdKey,topParent名称的方法eg:
    comboselect.setProperties({idKey:'id',textKey:'text',parentIdKey:'parentid',topParentValue:'-1'});

    初始化下拉列表集合的方法eg:
    comboselect.initSelect('gd');
 */

var topParentValue = "-";
var idKey = "id", textKey = "text", parentIdKey = "parentid";

var ComboSelectFactory = function(data){
    return new ComboSelect(arguments);
}

var ComboSelect = function(data){
    this.myData = [].slice.call(data, 0, 1)[0];
    this.ids     = [].slice.call(data, 1);
    this.setProperties({});
}

ComboSelect.prototype.setProperties = function(opt){
    this.topParentValue = opt.topParentValue || topParentValue;
    this.idKey             = opt.idKey || idKey;
    this.textKey         = opt.textKey || textKey;
    this.parentIdKey     = opt.parentIdKey || parentIdKey;

    for(var i=0, len=this.ids.length-1; i<len; i++){
        var o = this.$(this.ids[i]);
        //给第i个select添加change事件，初始化该下拉列表的下级select
        this.addEventHandler(o, 'change', this.eventHandle(o,i));
    }

    this.initChild(null, 0);
}

ComboSelect.prototype.eventHandle = function(o,i) {
    var self     = this;
    var oreg    = o;
    var index    = i+1;
    return function() {
        self.initChild(oreg, index);
    }
}

/**
 * 说明：              当select选定一个option后，根据该option的值，查找 parentID 为该 optionID 的项，
 *                    生成option，插入下级select。
 * @params:
 *         oSelect:     父级select对象
 *         index:       父级select索引
 */
ComboSelect.prototype.initChild = function(oSelect, index){
    var p = null == oSelect ? this.topParentValue : oSelect.options[oSelect.selectedIndex].value;
    var ds = this.getChilds(p);
    this.clearSelect(index);
    var child = this.$(this.ids[index]);
    for(var i=0, len=ds.length; i<len; i++){
        var currentObj = ds[i];
        child.options[child.length] = new Option(currentObj[this.textKey], currentObj[this.idKey]);
    }
}

/**
 * 说明：              查找指定ID的子
 * @params:
 *        parentID:     查找该ID的子
 *        returns:    子的array
 */
ComboSelect.prototype.getChilds = function(parentID) {
    var childs = [];
    for(var i=0, len=this.myData.length; i<len; i++){
        if(parentID == this.myData[i][this.parentIdKey]){
            childs.push(this.myData[i]);
        }
    }
    return childs;
}

/**
 * 说明：              将索引以下的select清空
 * @params:
 *         index:      父级对象索引
 */
ComboSelect.prototype.clearSelect = function(index) {
    for(var i=index, len=this.ids.length; i<len; i++){
        this.$(this.ids[i]).length=1;
    }
}

/**
 * 说明：              初始化下拉列表集合。
 * @params:
 *         id:         选中项ID
 */
ComboSelect.prototype.initSelect = function(id){
    var parentids = [];
    parentids = this.getParent(id);
    for (var i=0, len=this.ids.length; i<len; i++){
        //顶层直接初始化，子级select用父级的选中值初始化
        if(i==0){
            this.initChild(null, 0);
        }else{
            this.initChild(this.$(this.ids[i-1]),i);
        }
        if(parentids[i]!=null){
            this.$(this.ids[i]).value = parentids[i][this.idKey];
        }
    }
}

/**
 * 说明：              得到指定ID的父级array
 * @params:
 *         id:         选中项ID
 */
ComboSelect.prototype.getParent = function(id) {
    var parents = [];
    for(var i=0, len=this.myData.length; i<len; i++){
        if(id == this.myData[i][this.idKey]){
            if(this.myData[i][this.parentIdKey] == this.topParentValue){
                parents.push(this.myData[i]);
                break;
            }else{
                parents = this.getParent(this.myData[i][this.parentIdKey]);
                parents.push(this.myData[i]);
            }
        }
    }
    return parents;
}

ComboSelect.prototype.$ = function(sid) {
    return document.getElementById(sid);
}

ComboSelect.prototype.addEventHandler = function(oTarget, sEventType, fnHandler) {
    if (oTarget.addEventListener) {
        oTarget.addEventListener(sEventType, fnHandler, false);
    } else if (oTarget.attachEvent) {
        oTarget.attachEvent("on" + sEventType, fnHandler);
    } else {
        oTarget["on" + sEventType] = fnHandler;
    }
}

html页面中的调用

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

<script type='text/javascript' src='scripts/ComboSelect.js'></script>

</head>
<script type="text/javascript">

/*-- 数据定义 ---------------------------*/
    var data = [];

    data.push({id:'cn', text:'中国', parentid:'-'});

    data.push({id:'fj', text:'福建', parentid:'cn'});
    data.push({id:'gd', text:'广东', parentid:'cn'});

    data.push({id:'fz', text:'福州', parentid:'fj'});
    data.push({id:'xm', text:'厦门', parentid:'fj'});
    data.push({id:'ly', text:'龙岩', parentid:'fj'});

    data.push({id:'fz-fq', text:'福州1', parentid:'fz'});
    data.push({id:'fz-mh', text:'福州2', parentid:'fz'});
    data.push({id:'fz-cl', text:'福州3', parentid:'fz'});

    data.push({id:'xm-dn', text:'厦门1', parentid:'xm'});
    data.push({id:'xm-jm', text:'厦门2', parentid:'xm'});
    data.push({id:'xm-xl', text:'厦门3', parentid:'xm'});

    data.push({id:'yl-xl', text:'龙岩1', parentid:'ly'});
    data.push({id:'yl-lc', text:'龙岩2', parentid:'ly'});
    data.push({id:'yl-sh', text:'龙岩3', parentid:'ly'});
    data.push({id:'yl-wp', text:'龙岩4', parentid:'ly'});

    data.push({id:'gz', text:'广州', parentid:'gd'});
    data.push({id:'sz', text:'深圳', parentid:'gd'});
    data.push({id:'mx', text:'梅县', parentid:'gd'});

    data.push({id:'gz-fq', text:'广州1', parentid:'gz'});
    data.push({id:'gz-mh', text:'广州2', parentid:'gz'});
    data.push({id:'gz-cl', text:'广州3', parentid:'gz'});

    data.push({id:'sz-dn', text:'深圳1', parentid:'sz'});
    data.push({id:'sz-jm', text:'深圳2', parentid:'sz'});
    data.push({id:'sz-xl', text:'深圳3', parentid:'sz'});

    data.push({id:'mx-xl', text:'梅县1', parentid:'mx'});
    data.push({id:'mx-lc', text:'梅县2', parentid:'mx'});
    data.push({id:'mx-sh', text:'梅县3', parentid:'mx'});
    data.push({id:'mx-wp', text:'梅县4', parentid:'mx'});

    data.push({id:'ny', text:'纽约', parentid:'am'});
    data.push({id:'hsd', text:'华盛顿', parentid:'am'});
    data.push({id:'am', text:'美国', parentid:'-'});

function makeArray(arg1, arg2){
    return [ this, arg1, arg2 ];
}
//在onload后执行
window.onload = function() {
    comboselect = ComboSelectFactory(data, 'p1', 'p2', 'p3', 'p4');
    comboselect.setProperties({idKey:'id', texKey:'text', parentIdKey:'parentid', topParentValue:'-'});
    comboselect.initSelect('mx-wp');
}
</script>
<body>
    <select id="p1"><option>-选择-</option></select><br/>
    <select id="p2"><option>-选择-</option></select><br/>
    <select id="p3"><option>-选择-</option></select><br/>
    <select id="p4"><option>-选择-</option></select>
</body>  

</html>

comboselect.setProperties方法可以根据数据值自己自定义

代码已上传https://github.com/sunfengjiajia/spring-boot-test