跨浏览器读取XML

这里跨浏览器，但是只能读取字符串XML文档，可以通过Ajax方式load一个XML文档，将文件XML转变为字符串

// 跨浏览器返回XML DOM对象
function getXMLDOM(xmlStr) {
var xmlDom = null;

if (typeof window.DOMParser != 'undefined') {
xmlDom = (new DOMParser).parseFromString(xmlStr, 'text/xml');
var errors = xmlDom.getElementsByTagName('parsererror');
if (errors.length > 0) {
throw new Error('错误信息：' + errors[0].textContent);
}
} else if (typeof window.ActiveXObject != 'undefined') {
var version = ['MSXML2.DOMDocument6.0', 'MSXML2.DOMDocument3.0',
'MSXML2.DOMDocument'];

for (var i = 0; i < version.length; i++) {
try {
var xmlDom = new ActiveXObject(version[i]);
} catch (e) {
// 跳过
}
}
xmlDom.loadXML(xmlStr);
if (xmlDom.parseError != 0) {
throw new Error('错误信息：' + xmlDom.parseError.reason);
}
return xmlDom;
} else {
throw new Error('您的系统或浏览器不支持XML DOM对象！');
}

return xmlDom;
}

序列化XML，序列号的意思，这里就不做解释了哈。

function serializerXML(xmlDom) {
var xml = '';
if (typeof window.XMLSerializer != 'undefined') {
xml = (new XMLSerializer()).serializeToString(xmlDom);
} else if (typeof xmlDom.xml != 'undefined') {
xml = xmlDom.xml;
}
return xml;
}

现在XMLDOM获取到了，我们接下来获取节点，其中xpath为节点名称。

//跨浏览器单一节点
function selectSingleNode(xmlDom, xpath) {
var node = null;
if (typeof xmlDom.evaluate != 'undefined') {		//W3C
var patten = /\[(\d+)\]/;
var flag = xpath.match(patten);
var num = 0;
if (flag !== null) {
num = parseInt(RegExp.$1) + 1;
xpath = xpath.replace(patten, '[' + num + ']');
}
var result = xmlDom.evaluate(xpath, xmlDom, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);
if (result !== null) {
node = result.singleNodeValue;
}
} else if (typeof xmlDom.selectSingleNode != 'undefined') {		//IE
node = xmlDom.selectSingleNode(xpath);
}

return node;
}

获取节点集合

//跨浏览器节点集合
function selectNodes(xmlDom, xpath) {
var nodes = [];
if (typeof xmlDom.evaluate != 'undefined') {		//W3C
var patten = /\[(\d+)\]/;
var flag = xpath.match(patten);
var num = 0;
if (flag !== null) {
num = parseInt(RegExp.$1) + 1;
xpath = xpath.replace(patten, '[' + num + ']');
}
var result = xmlDom.evaluate(xpath, xmlDom, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE, null);
if (result != null) {
var node = null;
while ((node = result.iterateNext()) !== null) {
nodes.push(node);
}
}
} else if (typeof xmlDom.selectNodes != 'undefined') {		//IE
nodes = xmlDom.selectNodes(xpath);
}

return nodes;
}

　　测试代码

var xmlStr = '<root><user id="5">Lee</user><user id="6">Koko</user></root>';
var xmlDom = getXMLDOM(xmlStr);
var nodes = selectNodes(xmlDom, 'root/user');
alert(nodes.length);
alert(serializerXML(nodes[0]));
alert(serializerXML(nodes[1]));