如何在IE和Firefox中解析javascript中的XML？

Question

我正在尝试编写一段代码来解析IE和Firefox中的javascript.

以下适用于IE,并且功能无需在firefox中抱怨

function XmlDom(sXml){
    var oXml;
    if (window.ActiveXObject) {
        // ie
        oXml = new ActiveXObject("Microsoft.XMLDOM");
        oXml.resolveExternals = false;
        oXml.async = false;
        oXml.loadXML(sXml);
    }
    else if (window.DOMParser){

        var parser = new DOMParser(); 
        oXml = parser.parseFromString(sXml, "text/xml");

    }
return oXml
}

以下适用于IE,但在Firefox下会出现错误(因为childNodes不存在)

var oXml = XmlDom(sourceXML);
var listHtml = "";
if (oXml.firstChild != null) {
    var childNodes = null;
    try {
        childNodes = oXml.lastChild.lastChild.firstChild.childNodes;
    }
    if (childNodes != null && childNodes.length > 0) {

        for (var i = 0; i < childNodes.length; i++) {

            var vehicleName = NodeText(SelectSingleNode(childNodes[i], 'VehicleName', 'VehicleName'));
            var vehicleId = NodeText(SelectSingleNode(childNodes[i], 'VehicleId', 'VehicleId'));

        }
    }
}

使用jquery给我在firefox下的正确行为,但在IE中不能正常工作(它找到正确数量的车辆,但每个都有一个空id和名称)

 $(sourceXml).find("Table1").each(function() {
        var vehicleId = $(this).find("VehicleId").text();
        var vehicleName = $(this).find("VehicleName").text();
    });

我坚信这两种方法都应该奏效.但是出了点问题.我爱一只手.

<?xml version="1.0" encoding="utf-16"?>
<DataSet>
  <xs:schema id="NewDataSet" xmlns="" xmlns:xs="http://www.w3.org/2001/XMLSchema"     xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" xmlns:msprop="urn:schemas-microsoft-com:xml-msprop">
    <xs:element name="NewDataSet" msdata:IsDataSet="true" msdata:UseCurrentLocale="true">
      <xs:complexType>
        <xs:choice minOccurs="0" maxOccurs="unbounded">
          <xs:element name="Table1">
            <xs:complexType>
              <xs:sequence>
                <xs:element name="VehicleId" msprop:metadatacolumnname="VehicleId" msprop:caption="VehicleId" type="xs:string" minOccurs="0" />
                <xs:element name="VehicleName" msprop:metadatacolumnname="VehicleName" msprop:caption="VehicleName" type="xs:string" minOccurs="0" />
            <xs:element name="SendAlarms" msprop:metadatacolumnname="SendAlarms" msprop:caption="SendAlarms" type="xs:string" minOccurs="0" />
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:choice>
  </xs:complexType>
  </xs:element>
  </xs:schema>
  <diffgr:diffgram xmlns:msdata="urn:schemas-microsoft-com:xml-msdata"   xmlns:diffgr="urn:schemas-microsoft-com:xml-diffgram-v1">
<NewDataSet>
  <Table1 diffgr:id="Table11" msdata:rowOrder="0" diffgr:hasChanges="inserted">
    <VehicleId>8</VehicleId>
    <VehicleName>AIS Gate</VehicleName>
    <SendAlarms>False</SendAlarms>
  </Table1>
  <Table1 diffgr:id="Table12" msdata:rowOrder="1" diffgr:hasChanges="inserted">
    <VehicleId>82</VehicleId>
    <VehicleName>Amigos</VehicleName>
    <SendAlarms>False</SendAlarms>
  </Table1> 
</NewDataSet>
</diffgr:diffgram>
</DataSet>

Answer 1

问题是Firefox的XML解析器没有忽略空白文本节点,而IE是,这意味着它oXml.lastChild.lastChild实际上是一个文本节点而且没有子节点.我不知道DOMParser在Firefox(和其他浏览器)中发现如何忽略空白节点,因此您必须以两种方式解决它:在将其传递给解析器parseFromString()方法之前删除空格,或者您以过滤掉空白文本节点的方式遍历XML DOM.

Firefox 3.5及更高版本支持DOM元素遍历API,这意味着你可以像使用性质firstElementChild,lastElementChild,nextElementSibling和previousElementSibling.Firefox 3.5还支持children元素的属性,该元素是作为元素的所有子节点的集合.Safari,Chrome和Opera的最新版本(我不确定具体细节)也支持这些属性.

最后一个选项使用标准DOM Level 1方法,因此可以在所有浏览器中使用,它是在遍历DOM之前手动删除所有空白节点.以下函数将以递归方式执行此操作:

function removeWhiteSpaceNodes(node) {
    var child = node.firstChild, nextChild;
    while (child) {
        nextChild = child.nextSibling;
        if (child.nodeType == 3 && /^\s*$/.test(child.nodeValue)) {
            node.removeChild(child);
        } else if (child.hasChildNodes()) {
            removeWhiteSpaceNodes(child);
        }
        child = nextChild;
    }
}