&#106avascript 调用XML制作连动下拉框-巨人网络通讯

&#106avascript 调用XML制作连动下拉框

作者：何耀
Thursday, June 5 2003 2:44 PM

传统的HTML页面中连动下拉框采用了两种方法：
1）直接将下拉框中的内容hardcode于html的javascript中，调用javascript函数循环写入下拉框中。这种方法不适用于下拉框内容经常改变的情况。因为数据源和javascript程序写死在同一页面。

html>
head>
title>List/title>
meta http-equiv="Content-Type" content="text/html; c
harset=gb2312">
script LANGUAGE="javascript">
!--
var onecount;
onecount=0;

subcat = new Array();
subcat[0] = new Array("徐汇区","01","001");
subcat[1] = new Array("嘉定区","01","002");
subcat[2] = new Array("黄浦区","01","003");
subcat[3] = new Array("南昌市","02","004");
subcat[4] = new Array("九江市","02","005");
subcat[5] = new Array("上饶市","02","006");

onecount=6;

function changelocation(locationid)
{
document.myform.smalllocation.length = 0;

var locationid=locationid;
var i;
document.myform.smalllocation.options[0] = new Option('====所有地区====','');
for (i=0;i onecount; i++)
{
if (subcat[i][1] == locationid)
{
document.myform.smalllocation.options[document.myform.smalllocation.length]
= new Option(subcat[i][0], subcat[i][2]);
}
}

}

//-->
/script>
/head>
body>
form name="myform" method="post">
select name="biglocation"
onChange="changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value)">
option value="01" selected>上海/option>
option value="02">江西/option>
/select>
select name="smalllocation">
option selected value="">==所有地区==/option>
/select>
/form>
script LANGUAGE="javascript">
!--
changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value);
//-->
/script>
/body>
/html>

2）javascript 直接读取数据库，取数据库中的记录写入javascript中，然后和第一种方法一样，调用javascript函数循环写入下拉框中。此方法将数据源与javascript分开，但,公开数据库的连接，从安全角度说，没有多少实用价值。

我的方法是将下拉框中的数据放在XML文件中，用javascript读XML文件，取得下拉框中的内容。

HTML 文件如下：
!-- myfile.html -->

html>
head>
script language="JavaScript" for="window" event="onload">
var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
var i=0;
var j=0;
var subclass_name="";
loadXML();
function loadXML(){
xmlDoc.async="false";
xmlDoc.load("account.xml");
xmlObj=xmlDoc.documentElement;
nodes = xmlDoc.documentElement.childNodes;
document.frm.mainclass.options.length = 0;
document.frm.subclass.options.length = 0;

for (i=0;ixmlObj.childNodes.length;i++){
labels=xmlObj.childNodes(i).getAttribute("display_name");
values=xmlObj.childNodes(i).text;
document.frm.mainclass.add(document.createElement("OPTION"));
document.frm.mainclass.options[i].text=labels;
document.frm.mainclass.options[i].value=values;

}

/script>

script language="JavaScript" >
var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
var i=0;
var j=0;

function deleteOption() {

}

for (i=0;ixmlObj.childNodes.length;i++){

var values="";
var lables="";

if (is_selected=="Y") return;
labels=xmlObj.childNodes(i).getAttribute("display_name");
values=xmlObj.childNodes(i).text;
//alert(labels+ " | "+main);
if (labels==main){

is_selected="Y";

for (j=0;jxmlObj.childNodes(i).childNodes.length;j++){
//subclass_name="document.frm.subclass";
labels=xmlObj.childNodes(i).childNodes(j).getAttribute("display_name");
values=xmlObj.childNodes(i).childNodes(j).text;
//alert(values);
document.frm.subclass.add(document.createElement("OPTION"));
document.frm.subclass.options[j].text=labels;
document.frm.subclass.options[j].value=values;

}

}
}
/script>

title>在HTML中调用XML数据/title>
/head>
body bgcolor="#FFFFFF">
FORM NAME="frm">
类型SELECT NAME="mainclass" OnChange='setsubclass(this[selectedIndex].text)'>/SELECT>
option selected value="" >/option>
子类SELECT NAME="subclass">/SELECT>
/form>
/body>
/html>

account.xml 如下：

?xml version="1.0" encoding="GB2312"?>

item>
class display_name="未选定">
subclass display_name="">Not Available/subclass>
/class>
class display_name="95788主叫卡">
subclass display_name="1152069589-1152069638">dangdang1/subclass>
subclass display_name="1152081031-1152081080">dangdang2/subclass>
subclass display_name="1152547201-1105254750">dangdang3/subclass>
subclass display_name="1152548401-1152548700">dangdang4/subclass>
subclass display_name="1152548701-1152549000">dangdang5/subclass>
subclass display_name="1156000001-1156010000">dangdang6/subclass>
/class>
class display_name="网上注册">
subclass display_name="1152000001-1152001000">zhuce_user1/subclass>
subclass display_name="1151001000-1151005000">zhuce_user2/subclass>
/class>
class display_name="通讯">
subclass display_name="1156030001-1156080000">tongxun/subclass>
/class>