js解析xml浏览器兼容性处理

/******************************************************************************
    说明：xml解析类
******************************************************************************/


function XMLDOCDocument() {
    this.xmlDoc = null;
    this.async = false;
    this.xml = null;
};


function createDocument() {
    if (typeof arguments.callee.activeXString != "string") {
        var versions = ["MSXML2.DOMDocument.6.0", "MSXML2.DOMDocument.3.0", "MSXML2.DOMDocument"],
        i, len;
        for (i = 0, len = versions.length; i < len; i++) {
            try {
                new ActiveXObject(versions[i]);
                arguments.callee.activeXString = versions[i];
                ActiveXObject(arguments.callee.activeXString);
                break;
            } catch (ex) {
                //跳过
            }
        }
    }
    return new ActiveXObject(arguments.callee.activeXString);
};
/*
描述：加载xml
*/
XMLDOCDocument.prototype.loadXML = function (xmlInfo) {
    //判断浏览器的类型
    //支持IE浏览器

    var isLoad = false;
    var xmlDomVersions = ['MSXML.2.DOMDocument.6.0', 'MSXML.2.DOMDocument.3.0', 'Microsoft.XMLDOM'];
    for (var i = 0; i < xmlDomVersions.length; i++) {
        try {
            this.xmlDoc = new ActiveXObject(xmlDomVersions[i]);
            this.xmlDoc.async = this.async;
            this.xmlDoc.loadXML(xmlInfo); //loadXML方法载入xml字符串
            this.xml = this.xmlDoc.documentElement.outerHTML;
            isLoad = true;
            break;
        } catch (e) {
        }
    }
    if (!isLoad) {
        if (typeof DOMParser != "undefined") {
            this.xmlDoc = (new DOMParser()).parseFromString(xmlInfo, "text/xml");
            this.xml = this.xmlDoc.documentElement.outerHTML;
            var errors = this.xmlDoc.getElementsByTagName("parsererror");
            if (errors.length) {
                throw new Error("XML parsing error:" + errors[0].textContent);
            }
        } else {
            throw new Error("No XML parser available.");
        }
    }
};

/*
说明：选择所有符合条件的节点
*/
XMLDOCDocument.prototype.selectNodes = function (xPath) {
    return this.xmlDoc.selectNodes(xPath);
};
/*
说明：选择一个符合条件的节点
*/
XMLDOCDocument.prototype.selectSingleNode = function (xPath) {
    return this.xmlDoc.selectSingleNode(xPath);
};


/*
说明：创建新节点
*/
XMLDOCDocument.prototype.createElement = function (nodeName) {
    return this.xmlDoc.createElement(nodeName);
};

/*
说明：创建新属性
*/
XMLDOCDocument.prototype.createAttribute = function (attrName) {
    return this.xmlDoc.createAttribute(attrName);
};
/*
说明：获得xml字符串
*/
XMLDOCDocument.prototype.getXml = function () {
    //return this.xmlDoc.xml;
    if (typeof this.xmlDoc.xml != "undefined") {

        return this.xmlDoc.xml;
    }
    else if (typeof XMLSerializer != "undefined") {
        return (new XMLSerializer()).serializeToString(this.xmlDoc);
    } else {
        throw new Error("Could not serialize XML DOM.");
    }
};
/*
说明：获得xml字符串
*/
XMLDOCDocument.prototype.toString = function () {
    //return this.xmlDoc.xml;
    if (typeof this.xmlDoc.xml != "undefined") {

        return this.xmlDoc.xml;
    }
    else if (typeof XMLSerializer != "undefined") {
        return (new XMLSerializer()).serializeToString(this.xmlDoc);
    } else {
        throw new Error("Could not serialize XML DOM.");
    }
};




// check for XPath implementation 
if (document.implementation.hasFeature("XPath", "3.0")) {
    // prototying the XMLDocument 
    XMLDocument.prototype.selectNodes = function (cXPathString, xNode) {
        if (!xNode) {
            xNode = this;
        }
        var oNSResolver = this.createNSResolver(this.documentElement)
        var aItems = this.evaluate(cXPathString, xNode, oNSResolver, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null)
        var aResult = [];
        for (var i = 0; i < aItems.snapshotLength; i++) {
            aResult[i] = aItems.snapshotItem(i);
        }
        return aResult;
    };

    // prototying the Element 
    Element.prototype.selectNodes = function (cXPathString) {
        if (this.ownerDocument.selectNodes) {
            return this.ownerDocument.selectNodes(cXPathString, this);
        }
        else {
            throw "For XML Elements Only";
        }
    };

    // prototying the XMLDocument 
    XMLDocument.prototype.selectSingleNode = function (cXPathString, xNode) {
        if (!xNode) { xNode = this; }
        var xItems = this.selectNodes(cXPathString, xNode);
        if (xItems.length > 0) {
            return xItems[0];
        }
        else {
            return null;
        }
    };

    // prototying the Element 
    Element.prototype.selectSingleNode = function (cXPathString) {
        if (this.ownerDocument.selectSingleNode) {
            return this.ownerDocument.selectSingleNode(cXPathString, this);
        }
        else { throw "For XML Elements Only"; }
    }

    Element.prototype.__defineGetter__("innerText",
        function () {
            return this.textContent;
        }
    );

    Element.prototype.__defineSetter__("innerText",
        function (sText) {
            this.textContent = sText;
        }
    );

};