XML Volume Practical Tips (4): Menu Linkage
Motivation:
Now let's do a small example of applying XML in IE: solving the linkage problem of double drop-down menus. Perhaps the most common example is to select a province and then change the city options, so let's try to use XML to complete it.
I have implemented some of the functions introduced before directly using XML+XSL files. You may not be very familiar with its usage, so I will use HMTL+XML this time, hoping to make everyone more familiar with it. Clear understanding - "XML can be so simple!":)
Materials:
XML Volume Select Menu Linkage
There are 2 files: Citys.xml and CitySelect.htm
Function:
After selecting a province, the corresponding city can be automatically displayed, which is convenient for users, effectively improves data interaction, and makes your page more colorful.
Effect:
Browse here
Code:
Citys.xml
<?xml version="1.0" encoding="gb2312"?>
<China>
<State id="1" name="江西">
<City>九江</City>
<City>南昌</City>
<City>庐山</City>
<City>景德镇</City>
</State>
<State id="2" name="北京">
<City>北京西</City>
<City>居庸关</City>
<City>清华园</City>
<City>周口店</City>
</State>
<State id="3" name="福建">
<City>福州</City>
<City>厦门</City>
<City>漳州</City>
</State>
<State id="4" name="甘肃">
<City>兰州</City>
<City>洛门</City>
<City>嘉峪关</City>
</State>
<State id="5" name="广东">
<City>广州</City>
<City>深圳</City>
<City>东莞</City>
<City>石牌</City>
</State>
<State id="6" name="安徽">
<City>合肥</City>
<City>黄山</City>
<City>九龙岗</City>
<City>马鞍山</City>
</State>
</China>CitySelect.htm
Custom function: ChooseState
(Read the province in XML data name and added to SelState's drop-down list)
function ChooseState()
{
var source;
var sourceName = "Citys.xml";
var source = new ActiveXObject('Microsoft.XMLDOM'); //创建一个 MSXML解析器实例
source.async = false;
source.load(sourceName); //装入XML文档
root = source.documentElement; //设置文档元素为根节点元素
sortField=root.selectNodes("//@name"); //搜索属性中含有name的所有节点
for(var i=0;i<sortField.length;++i) //增加省份名称到下拉列表
{
var oOption = document.createElement('OPTION');
oOption.text = " "+sortField[i].text+" ";
oOption.value = sortField[i].text;
form1.SelState.options.add(oOption);
}
ChooseCity();
}Custom function: ChooseCity
(Read the corresponding city in the XML data based on the currently selected province name name and added to SelCity's drop-down list)
function ChooseCity()
{
x=form1.SelState.selectedIndex; //读取省份下拉框的当前选项
y=form1.SelState.options[x].value;
sortField=root.selectNodes("//State[@name='"+y+"']/City&q uot;); //搜索name属性值等于
参数y的State节点下的所有city节点
for(var i=form1.SelCity.options.length-1;i>=0;--i) //撤消原来的列表项
{
form1.SelCity.options.remove(i)
}
for(var i=0;i<sortField.length;++i) //增加城市名称到下拉列表
{
var oOption = document.createElement('OPTION');
oOption.text = " "+sortField[i].text+" ";
oOption.value = sortField[i].text;
form1.SelCity.options.add(oOption);
}
}
Form source code
<BODY onLoad="ChooseState()"> <FORM action="" method="post" id="form1" name="form1"> <SELECT name="SelState" id="SelState" onchange="ChooseCity()" > </SELECT> <SELECT name="SelCity" id="SelCity" > </SELECT> </FORM> </BODY>
Postscript:
Just started learning When it comes to XML, I also have the same confusion as everyone else - "I have learned XML, but how should I use this XML?" This problem has hindered me for a long, long time...
Because e-commerce and software development are my expertise, I thought it would be better to start with what I am most familiar with. So I implemented some of the most commonly used functions in website construction in XML. You can do it too!
The above is the practical tips for XML volume (4): menu linkage content. For more related content, please pay attention to the PHP Chinese website (m.sbmmt.com)!
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