特点：通用性强、实现了script和html分离
一、文件及源码cs.js用函数和类两种方法实现，调用时只要调用一种就可以了。
<!--/** * Function to setup a CascadeSelect * @version build 20060324 * @author KimSoft (jinqinghua [at] gmail.com) * @update */
/** * setupCascadeSelect * @param cascadeSelect select object * @param parent data index of parent * @param nodes array contains data with structure [[parent, text, value],[],...[]] * @param [optional] is onchange */function setupCascadeSelect(cascadeSelect, parent, nodes, isOnChange) { if (isOnChange == null){ isOnChange = false; } cascadeSelect.onchange = function (){ setupCascadeSelect(this, this.options[this.selectedIndex].value, nodes, true); }; cascadeSelect.getAttr = function (attrName) { return this[attrName] ? this[attrName] : this.getAttribute(attrName); }; cascadeSelect.getElementById = function (id) { return this.form.elements[id] ? this.form.elements[id]: document.getElementById(id); }; cascadeSelect.setDisplayStyle = function(value) { if (!this.multiple){ this.style.display = value; } var subElement = this.getElementById(this.getAttr("subElement")); if (subElement != undefined){ subElement.setDisplayStyle = this.setDisplayStyle; } }; nodes.getChildNodesByParent = function (parent) { var childNodes = new Array(); if (parent + "" == ""){ return childNodes; } for (var i = 0; i < nodes.length; i++){ if (nodes[i][0] != undefined && nodes[i][0] == parent){ childNodes[childNodes.length] = nodes[i]; } } return childNodes; }
if(!isOnChange){ cascadeSelect.options.length = 0; var defaultText = cascadeSelect.getAttr("defaultText"); var defaultValue = cascadeSelect.getAttr("defaultValue"); var selectedValue = cascadeSelect.getAttr("selectedValue");
if (defaultText != undefined && defaultValue != undefined){ cascadeSelect.options[cascadeSelect.options.length] = new Option(defaultText, defaultValue); } var childNodes = nodes.getChildNodesByParent(parent); for (var i = 0; i < childNodes.length; i++){ cascadeSelect.options[cascadeSelect.options.length] = new Option(childNodes[i][1], childNodes[i][2]); if (selectedValue != undefined && selectedValue == childNodes[i][2]){ cascadeSelect.selectedIndex = cascadeSelect.options.length - 1; } } }
if (cascadeSelect.options.length > 0){ cascadeSelect.setDisplayStyle(""); var subElement = cascadeSelect.getElementById(cascadeSelect.getAttr("subElement")); if (subElement != undefined){ setupCascadeSelect(subElement, cascadeSelect.options[cascadeSelect.selectedIndex].value, nodes, false); } } else { cascadeSelect.setDisplayStyle("none"); }}
/** * 以类的方法实现连动 */function CascadeSelect(element, parent, nodes){ this.form = element.form; this.nodes = nodes; this.attributes = { "subElement" : "subElement", "defaultText" : "defaultText", "defaultValue" : "defaultValue", "selectedValue" : "selectedValue" } this.build(element, parent, false);}
CascadeSelect.prototype.getElementById = function (id) { return this.form.elements[id] ? this.form.elements[id]: document.getElementById(id);};
CascadeSelect.prototype.getAttribute = function (element, attrName) { return element[attrName] ? element[attrName] : element.getAttribute(attrName);};
CascadeSelect.prototype.getChildNodesByParent = function (parent) { var childNodes = new Array(); if (parent + "" == ""){ return childNodes; } for (var i = 0; i < this.nodes.length; i++){ if (this.nodes[i][0] != undefined && this.nodes[i][0] == parent){ childNodes[childNodes.length] = this.nodes[i]; } } return childNodes; }
CascadeSelect.prototype.setDisplayStyle = function(element, value) { var cs = this; if (!element.multiple){ element.style.display = value; } var subElement = this.getElementById(this.getAttribute(element, this.attributes["subElement"])); if (subElement != undefined){ subElement.setDisplayStyle = function () {cs.setDisplayStyle;} } };
CascadeSelect.prototype.build = function (element, parent, isOnChange) { var cs = this; element.onchange = function () { cs.build(this, this.options[this.selectedIndex].value, true); } if(!isOnChange){ element.options.length = 0; var defaultText = this.getAttribute(element, this.attributes["defaultText"]); var defaultValue = this.getAttribute(element, this.attributes["defaultValue"]); var selectedValue = this.getAttribute(element, this.attributes["selectedValue"]); //alert(selectedValue);
if (defaultText != undefined && defaultValue != undefined){ element.options[element.options.length] = new Option(defaultText, defaultValue); } var childNodes = this.getChildNodesByParent(parent); for (var i = 0; i < childNodes.length; i++){ element.options[element.options.length] = new Option(childNodes[i][1], childNodes[i][2]); //alert("childNodes[i][2]:" + childNodes[i][2]); if (selectedValue != undefined && selectedValue == childNodes[i][2]){ alert(selectedValue); element.selectedIndex = element.options.length - 1; } } }
if (element.options.length > 0){ this.setDisplayStyle(element, ""); var subElement = this.getElementById(this.getAttribute(element, this.attributes["subElement"])); if (subElement != undefined){ this.build(subElement, element.options[element.selectedIndex].value, false); } } else { this.setDisplayStyle(element, "none"); }}//-->
二、demo加说明
demo_cs2.htm
<html><body><script language="JavaScript" type="text/javascript" src="cs.js"></script><script language="JavaScript" type="text/javascript"><!--/*生成联动菜单数组，可以从数据库生成，形式如下[[parent, text, value], [parent, text, value]]优化部分：一、用数据直接量减少生成的字符，数据结构简单二、parent,value部分尽量使用数字形式，value部分尽量使用单引号，以减少生成的数据大小*/var aryCertType = [[0,'外语证书',671],[71,'大学英语四级',672],[71,'大学英语六级',673],[71,'剑桥商务英语证书',674],[71,'英语专业四级',675],[71,'英语专业六级',676],[71,'英语专业八级',677],[71,'托福',678],[71,'国际英文水平测试',679],[671,'中级口译证书',680],[671,'高级口译证书',681],[671,'日语一级证书',682],[671,'日语二级证书',683],[671,'日语三级证书',684],[671,'日语四级证书',685],[671,'俄语四级证书',686],[671,'俄语六级证书',687],[671,'法语四级证书',688],[671,'法语六级证书',689],[671,'德语四级证书',690],[671,'德语六级证书',691],[671,'GRE',692],[671,'GMAT',693],[671,'FCE',694],[671,'全国公共英语等级考试',695],[0,'计算机证书',696],[696,'全国计算机应用技术证书',697],[696,'全国计算机软件技术资格与水平考试',698],[696,'初级程序员',699],[696,'程序员',700],[696,'高级程序员',701],[696,'系统分析员',702],[696,'全国计算机等级一级',703],[696,'全国计算机等级二级',704],[696,'全国计算机等级三级A',705],[696,'全国计算机等级四级',706],[696,'微软认证专家',707],[696,'微软认证系统工程师',708],[696,'微软认证系统开发师',709],[696,'Cisco认证网络规划和网络支持工程师',710],[696,'Cisco认证网络专家',711],[696,'Novell授权网络管理师',712],[696,'Novell授权网络工程师',713],[696,'Novell授权高级网络工程师',714],[696,'Novell授权Internet专家',715],[696,'Intel认证方案咨询专家',716],[696,'SUN认证Java程序员',717],[696,'3com认证网络大师',718],[696,'Adobe认证专家',719],[696,'Lotus专家认证应用开发师',720],[696,'Lotus专家认证系统管理师',721],[696,'Sybase认证考试',722],[696,'Cisco认证网络支持工程师',723],[696,'Cisco认证资深网络支持工程师',724],[696,'Cisco认证网络设计工程师',725],[696,'Cisco认证资深网络设计工程师',726],[696,'计算机初级',727],[696,'计算机中级',728],[696,'网络初级证书',729],[696,'全国计算机等级三级B',730],[0,'会计证书',731],[731,'注册会计师',732],[731,'会计上岗证',733],[731,'助理会计师',734],[731,'中级会计师',735],[731,'高级会计师',736],[731,'会计电算化证书',737],[731,'国际财务会计证书',738],[0,'职称证书',739],[739,'初级工程师',740],[739,'中级工程师',741],[739,'高级工程师',742],[739,'助理工程师',743],[739,'初级经济师',744],[739,'中级经济师',745],[739,'高级经济师',746],[740,'助理经济师',747]]
/*文档加载完成时给控件加载自定义属性subElement: 可选的。指定一个子对象，必须为一个HTML Select控件 selectedValue: 可选的。指定选定的值，在回显示时非常方便defaultText: 可选的。默认文本defaultValue: 可选的。默认值优化的好处：一、集中到Script里，方便管理二、防止一些编辑器报告讨厌的XX标准不支持此属性的警告三、让网页通过标准验证*/window.onload = function(){ form = document.forms[0]; form.certType.setAttribute("subElement", "certName"); //form.certType.setAttribute("selectedValue", 739); form.certType.setAttribute("defaultText", "不限1级"); form.certType.setAttribute("defaultValue", ""); form.certName.setAttribute("selectedValue", 746); form.certName.setAttribute("defaultText", "不限2级"); form.certName.setAttribute("defaultValue", "");
/*调用优化后的好处：一、只要一个方法，调用方便，重用性高二、优化了算法，执行速度快*/ //setupCascadeSelect(form.certType, 0, aryCertType, false); new CascadeSelect(form.certType, 0, aryCertType);}--></script><form name="form1" method="post" action=""> <select name="certType"> </select> <select name="certName" οnchange="alert('xx');"> </select></form><div id="times"></div></body></html>
三、不足的地方
1、onchange事件被重定义了，如果想在onchage执行其它的东东，想办法吧。:)
2、修改时的回显
