javascript跨浏览器操作xml

//跨浏览器获取xmlDom

 function getXMLDOM(xmlStr) {
     var xmlDom = null;
     if (typeof window.DOMParser != 'undefined') {
         xmlDom = (new DOMParser).parseFromString(xmlStr,'text/xml'); //创建xmlDom对象
         var errors = xmlDom.getElementsByTagName('parsererror');
         if(errors.length > 0) {
             throw new Error('XML格式有误:'+errors[0].textContent);
         }
         return xmlDom;
     } else if (typeof window.ActiveXObject != 'undefined') {
         var version = [
             'MSXML2.DOMDocument.6.0',
             'MSXML2.DOMDocument.3.0',
             'MSXML2.DOMDocument'
         ];
         for(var i=0;i<version.length;i++) {
             try {
                 var xmlDom = new ActiveXObject(version[i]);
             } catch (e) {
                 //遇到错误跳过,继续执行try
             }
         }
         xmlDom.loadXML(xmlStr);
         if(xmlDom.parseError != 0) { //使用 !+ 号
             throw new Error('错误信息为:' + xmlDom.parseError.reason);
         }
         return xmlDom;
     } else {
         throw new Error('系统或浏览器不支持xmlDom对象!');
     }
     return xmlDom;
 }

/*
DOM2没有序列化XML的属性，XMLSerializer类型来帮助序列化XML字符串。
IE9、Safari、Chrome和Opera都支持这个类型。
*/

 function serializerXML(xmlDom) {
     var xml = null;
     if(typeof window.XMLSerializer != 'undefined') {//w3c的序列化
             var serializer = new XMLSerializer();
             xml = serializer.serializeToString(xmlDom);
     } else if(typeof xmlDom.xml != 'undefined') { //ie直接序列化
             xml = xmlDom.xml;
     }
     return xml;
 }

//跨浏览器获取xml单一节点

 function selectSingleNode(xmlDom,xpath) {
     var node = null;
     if(typeof xmlDom.evaluate != 'undefined') { //w3c
         var patt = /\[(\d+)\]/;
         var num = null;
         var flag = xpath.match(patt);
         if (flag) {
             num = parseInt(RegExp.$1) + 1;//w3c下标从1开始,如0加1
             xpath = xpath.replace(patt,'['+num+']'); //root/user[1]
         }
         var result = xmlDom.evaluate(xpath,xmlDom,null,XPathResult.FIRST_ORDERED_NODE_TYPE,null);
         if(result != null) {
             node = result.singleNodeValue; //w3c默认的下标是1
         }
     } else if (typeof xmlDom.selectSingleNode != 'undefined') {//ie中unknown而非 undefined
         node = xmlDom.selectSingleNode(xpath);
     }
     return node;
 }

//跨浏览器获取xml所有节点

 function selectNodes(xmlDom,xpath) {
     var nodes = [];
     if(typeof xmlDom.evaluate != 'undefined') { //w3c
         var patt = /\[(\d+)\]/;
         var num = null;
         var flag = xpath.match(patt);
         if(flag) {
             num = parseInt(RegExp.$1) + 1;
             xpath = xpath.replace(patt,'['+num+']');
         }
         var result = xmlDom.evaluate(xpath,xmlDom,null,XPathResult.ORDERED_NODE_ITERATOR_TYPE,null);
         var node = null;
         if(result != null) {
             while ((node = result.iterateNext()) !== null) {
                 nodes.push(node);
             }
         }
     } else if (typeof xmlDom.selectNodes != 'undefined') { //unkonwn
         nodes = xmlDom.selectNodes(xpath);
     }
     return nodes;
 }

 var xmlStr = '<root><name id="d1">du1</name><name id="d2">du2</name></root>';
 var xmlDom = getXMLDOM(xmlStr);
 var nodes = selectNodes(xmlDom,'root/name');
 //alert(nodes.length);
 //alert(serializerXML(xmlDom)); //序列化xmlStr
 //alert(serializerXML(selectSingleNode(xmlDom,'root/name[0]'))); //序列化单一节点

 alert(serializerXML(nodes[0]));//<name id="d1">du1</name>
 alert(serializerXML(nodes[1]));