在 XML 文档中搜索某个元素/属性值并返回该元素

Question

所以我得到了这段代码，它从 XML（产品目录）中获取元素并将它们列在表中。我现在要做的是从该 XML 中返回只有 1 个包含所有元素的产品。例如，我想从目录中只获取我想查看的具有特定序列号的产品。

这是我的 XML 文档：

<CATALOG>
    <PRODUCT>
       <SERIAL>123ABC</SERIAL>
       <PRODNR>1234</PRODNR>
       <PRODNM>COOLER</PRODNM>
       <ACCNAME>JOHN</ACCNAME>
       <NRDOC>0001</NRDOC>
    </PRODUCT>
    <PRODUCT>
       <SERIAL>234BCD</SERIAL>
       <PRODNR>2345</PRODNR>
       <PRODNM>MOUSEPAD</PRODNM>
       <ACCNAME>STEVE</ACCNAME>
       <NRDOC>0002</NRDOC>
    </PRODUCT>
    <PRODUCT>
       <SERIAL>345CDE</SERIAL>
       <PRODNR>3456</PRODNR>
       <PRODNM>KEYBOARD</PRODNM>
       <ACCNAME>WILLIAM</ACCNAME>
       <NRDOC>0003</NRDOC>
    </PRODUCT>
    <PRODUCT>
       <SERIAL>456DEF</SERIAL>
       <PRODNR>4567</PRODNR>
       <PRODNM>MOUSE</PRODNM>
       <ACCNAME>MARCUS</ACCNAME>
       <NRDOC>0004</NRDOC>
    </PRODUCT>
</CATALOG>

这是我目前的代码：

function loadXMLDoc(url) {
var serialNumber = document.getElementById('searchBox').value;
var xmlhttp;
var txt, xx, x, i;
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
    xmlhttp = new XMLHttpRequest();
}
else {// code for IE6, IE5
    xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function () {
    if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        txt = "<table border='1'><tr><th>Product number</th><th>Product name</th><th>Account name</th><th>Document number</th></tr>";
        x = xmlhttp.responseXML.documentElement.getElementsByTagName("PRODUCT");
        for (i = 0; i < x.length; i++) {
            txt = txt + "<tr>";
            xx = x[i].getElementsByTagName("PRODNM");
            {
                try {
                    txt = txt + "<td>" + xx[0].firstChild.nodeValue + "</td>";
                }
                catch (er) {
                    txt = txt + "<td>&nbsp;</td>";
                }
            }
            xx = x[i].getElementsByTagName("PRODNR");
            {
                try {
                    txt = txt + "<td>" + xx[0].firstChild.nodeValue + "</td>";
                }
                catch (er) {
                    txt = txt + "<td>&nbsp;</td>";
                }
            }
            xx = x[i].getElementsByTagName("ACCNAME");
            {
                try {
                    txt = txt + "<td>" + xx[0].firstChild.nodeValue + "</td>";
                }
                catch (er) {
                    txt = txt + "<td>&nbsp;</td>";
                }
            }
            xx = x[i].getElementsByTagName("NRDOC");
            {
                try {
                    txt = txt + "<td>" + xx[0].firstChild.nodeValue + "</td>";
                }
                catch (er) {
                    txt = txt + "<td>&nbsp;</td>";
                }
            }
            txt = txt + "</tr>";
        }
        txt = txt + "</table>";
        document.getElementById('showTable').innerHTML = txt;
    }
}
xmlhttp.open("GET", url, true);
xmlhttp.send();

}

Answer 1

我会使用 XPath 来选择必要的 PRODUCT 节点：

var path = '//SERIAL[text()="' + serialNumber + '"]/..';
var x = document.evaluate(path, xmlhttp.responseXML.documentElement, null, 9, null).singleNodeValue;

_{注意：（document.selectNodes(xpath) 用于 IE）}

演示：http://plnkr.co/edit/9hp6kM5OT8LEYrTCrCqN?p=preview

或者您可以简单地遍历所有 PRODUCT 节点并过滤具有搜索 ID 的节点。