var isIE    = navigator.userAgent.indexOf("MSIE")>0;
var XMLJS = function(){};

XMLJS.apply = function(o, c, defaults){
    if(defaults){
        // no "this" reference for friendly out of scope calls
        XMLJS.apply(o, defaults);
    }
    if(o && c && typeof c == 'object'){
        for(var p in c){
            o[p] = c[p];
        }
    }
    return o;
};

XMLJS.apply(XMLJS, {
	docObjs : new Array,
	/**
	 * 初始化xml对象文件连接池
	 */
	initDocs : function(count)
	{
		if(count == null) 
			count = 3;
		
		for(var i = 0; i < count; i++)
		{
			XMLJS.docObjs[i] = new Object;
			if(isIE)
			{
				XMLJS.docObjs[i].doc = new ActiveXObject('Microsoft.XMLDOM');
				XMLJS.docObjs[i].doc.async = false;
				XMLJS.docObjs[i].free = true;
			}
			else
			{
				XMLJS.docObjs[i].doc = new DOMParser();
				//XMLJS.docObjs[i].doc = document.implementation.createDocument("", "", null);
				XMLJS.docObjs[i].doc.async = false;
				XMLJS.docObjs[i].free = true;
			}
	
		}
	},
	
	
	/**
	 * 获得空闲xml文件docObj对象
	 */
	getFreeDocObj : function ()
	{
		var docObj = null;
		
		for(var i = 0; i < XMLJS.docObjs.length; i++)
		{
			if(XMLJS.docObjs[i].free)
			{
				XMLJS.docObjs[i].free = false;
				docObj = XMLJS.docObjs[i];
				break;
			}
		}
		
		return docObj;
	},
	
	/**
	 * 解析xml
	 */
	parseXML : function (xmlContent)
	{
		xmlContent = xmlContent.replace(/&lt;/g,"<");
	 	xmlContent = xmlContent.replace(/&gt;/g,">");
	 	xmlContent = xmlContent.replace(/&quot;/g,"'");
	 
		var docObj = XMLJS.getFreeDocObj();
		if(isIE)
		{ 
			docObj.doc.loadXML (xmlContent);//解析字符串不能用load必须用loadXML.(load解析载入文档的)
			var doc = docObj.doc;
			docObj.free = true;
			return doc;
		}
		else
		{
			var XmlDom = docObj.doc.parseFromString(xmlContent,"text/xml");
			docObj.free = true;
			return XmlDom;
		}
	},
	
	/**
	 * 解析xml
	 */
	parseXML2 : function (xmlContent)
	{
		xmlContent = xmlContent.replace(/&lt;/g,"<");
	 	xmlContent = xmlContent.replace(/&gt;/g,">");
	 	xmlContent = xmlContent.replace(/&quot;/g,"'");
	 	
		var xmlDoc;
		if(isIE)
		{ 
			xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
			xmlDoc.async = false;
			xmlDoc.loadXML(xmlContent);
			return xmlDoc;
		}
		else
		{
			xmlDoc = new DOMParser();
			var XmlDom = xmlDoc.parseFromString(xmlContent,"text/xml");
			return XmlDom;
		}
	},
	
	/**
	 * 获取xml子节点
	 * @param{domNode}dom节点
	 * @param{subNodeName}子节点名称
	 */
	getXMLSubNodes : function (domNode, subNodeName)
	{
		var subNodes = [];
		
		var currentNode = domNode;
		var childNodes = null;
		
		var paths = subNodeName.split ("/");
		
		for (var i = 0; paths != null && i < paths.length-1; i++)
		{
			if (paths[i] == "")
				continue;
			
			childNodes = currentNode.childNodes;
		
			for (var j = 0; childNodes != null && j < childNodes.length; j++)
			{
				if (childNodes[j].nodeName.toLowerCase() == paths[i].toLowerCase())
				{
					currentNode = childNodes[j];
					break;
				}
			}
		}
		
		childNodes = currentNode.childNodes;
		
		for (var i = 0; i < childNodes.length; i++)
		{
			if (childNodes[i].nodeName.toLowerCase() == paths[paths.length-1].toLowerCase())
				subNodes.push (childNodes[i]);
		}
		
		return subNodes;
	},
	
	/**
	 * 获取xml根节点
	 * @param{doc}xml对象
	 */
	getXMLRootNode : function (doc)
	{
		if (doc == null)
			return null;
		
		return doc.documentElement;
	},
	
	getXMLChildNodes: function(root)
	{
		var itemNodes = [];
		var nodes = root.childNodes;
		
		for(var i=0;i<nodes.length;i++)
		{
			if(nodes[i].nodeType == 1)
			{
				itemNodes.push(nodes[i]);
				//alert(nodes[i].nodeName +  nodes[i].nodeType);
			}
		}
		
		return itemNodes;
	},
	
	getXMLChildNode: function(doc_el, nodeName)
	{
		var element = doc_el.getElementsByTagName (nodeName);
		return element.documentElement;
	},
	
	/**
	 * 获取xml节点的值
	 * @param{doc}xml对象
	 * @param{NodeName}节点名称
	 */
	getXMLNodeValue : function (doc,nodeName)
	{
		if (doc == null)
		{
			return null;
		}
		return XMLJS.getXMLSingleNodeValue (doc.documentElement, nodeName);
	},
	
	/**
	 * 简化 DOM 访问的函数
	 * @param{doc_el} req.responseXML.documentElement
	 * @param{name} getElementsByTagName("name"), element name
	 * @param{idx} element index,exp:elements[0].firstChild.data
	 * @return nodevalue
	 * 
	 */
	getXMLSingleNodeValue: function(doc_el, nodeName)
	{
		var element = doc_el.getElementsByTagName (nodeName);
		var nodevalue = "";
		if(element[0].firstChild != null)
		{
			nodevalue =element[0].firstChild.nodeValue;
		}
		return nodevalue;
		//return element[0].firstChild.nodeValue;
	},
	
	/**
	 * 获取xml节点的值
	 * @param{doc}xml对象
	 * @param{NodeName}节点名称
	 */
	getAttributeNodeValues : function (doc_el,nodeName,attributeName)
	{
		if (doc_el == null)
		{
			return null;
		}
		var values = [];
		var len = doc_el.length;
		var value = "";
		for(var i = 0; i < len; i++)
		{
			if(doc_el[i].nodeName == nodeName)
			{
				value = doc_el[i].getAttribute(attributeName);
				values.push(value);
			}
		}
		return values;
	},
	
	/**
	 * 获取节点属性值的方法
	 * @param{doc_el} req.responseXML.documentElement
	 * @param{attributeName} node Attribute name
	 * @return nodevalue
	 * 
	 */
	getAttributeNodeValue: function(doc_el,attributeName)
	{
		var nodevalue = "";
		if(doc_el != null)
		{
			nodevalue =doc_el.getAttribute(attributeName);
		}
		return nodevalue;
	}
	
});
 /**
 * @deprecated 调用初始化xml文件对象方法,必须在定义后才能调用
 * 
 */
XMLJS.initDocs();