Parse XML using JavaScript [duplicate]

Question

I need to be able to parse XML using JavaScript. The XML will be in a variable. I would prefer not to use jQuery or other frameworks.

I have looked at this, XML > jQuery reading.

Millisent

I may be going to use PhoneGap to package the app and I don't know if that will work. – Millisent

Answer 1

I'm guessing from your last question, asked 20 minutes before this one, that you are trying to parse (read and convert) the XML found through using GeoNames' FindNearestAddress.

If your XML is in a string variable called txt and looks like this:

<address>
  <street>Roble Ave</street>
  <mtfcc>S1400</mtfcc>
  <streetNumber>649</streetNumber>
  <lat>37.45127</lat>
  <lng>-122.18032</lng>
  <distance>0.04</distance>
  <postalcode>94025</postalcode>
  <placename>Menlo Park</placename>
  <adminCode2>081</adminCode2>
  <adminName2>San Mateo</adminName2>
  <adminCode1>CA</adminCode1>
  <adminName1>California</adminName1>
  <countryCode>US</countryCode>
</address>

Then you can parse the XML with Javascript DOM like this:

if (window.DOMParser)
{
    parser = new DOMParser();
    xmlDoc = parser.parseFromString(txt, "text/xml");
}
else // Internet Explorer
{
    xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
    xmlDoc.async = false;
    xmlDoc.loadXML(txt);
}

And get specific values from the nodes like this:

//Gets house address number
xmlDoc.getElementsByTagName("streetNumber")[0].childNodes[0].nodeValue;

//Gets Street name
xmlDoc.getElementsByTagName("street")[0].childNodes[0].nodeValue;

//Gets Postal Code
xmlDoc.getElementsByTagName("postalcode")[0].childNodes[0].nodeValue;

JSFiddle

---

Feb. 2019 edit:

In response to @gaugeinvariante's concerns about xml with Namespace prefixes. Should you have a need to parse xml with Namespace prefixes, everything should work almost identically:

NOTE: this will only work in browsers that support xml namespace prefixes such as Microsoft Edge

// XML with namespace prefixes 's', 'sn', and 'p' in a variable called txt
txt = `
<address xmlns:p='example.com/postal' xmlns:s='example.com/street' xmlns:sn='example.com/streetNum'>
  <s:street>Roble Ave</s:street>
  <sn:streetNumber>649</sn:streetNumber>
  <p:postalcode>94025</p:postalcode>
</address>`;

//Everything else the same
if (window.DOMParser)
{
    parser = new DOMParser();
    xmlDoc = parser.parseFromString(txt, "text/xml");
}
else // Internet Explorer
{
    xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
    xmlDoc.async = false;
    xmlDoc.loadXML(txt);
}

//The prefix should not be included when you request the xml namespace
//Gets "streetNumber" (note there is no prefix of "sn"
console.log(xmlDoc.getElementsByTagName("streetNumber")[0].childNodes[0].nodeValue);

//Gets Street name
console.log(xmlDoc.getElementsByTagName("street")[0].childNodes[0].nodeValue);

//Gets Postal Code
console.log(xmlDoc.getElementsByTagName("postalcode")[0].childNodes[0].nodeValue);

Examination

Note that you can use jquery to quickly access the values, like $(xmlDoc).find('street:eq(0) :eq(0)').html() instead of xmlDoc.getElementsByTagName("streetNumber")[0].childNodes[0].nodeValue; – Removal

Looking up and integrating OP's other questions' answers is what I call high-level SO game. I'm impressed, well done! – Introduction

It works in >= IE6 :O – Stander

This does no work on Edge or IE if the tags have namespaces like <m:properties> – Zaragoza

@Zaragoza I don't seem to be having any issues with that... I'll add an example to my answer. – Examination

xmlDoc.getElementsByTagName("streetNumber")[0].innerHTML ...... OR ...... xmlDoc.getElementsByTagName("streetNumber")[0].textContent ??????? – Mineralogy

Answer 2

The following will parse an XML string into an XML document in all major browsers, including Internet Explorer 6. Once you have that, you can use the usual DOM traversal methods/properties such as childNodes and getElementsByTagName() to get the nodes you want.

var parseXml;
if (typeof window.DOMParser != "undefined") {
    parseXml = function(xmlStr) {
        return ( new window.DOMParser() ).parseFromString(xmlStr, "text/xml");
    };
} else if (typeof window.ActiveXObject != "undefined" &&
       new window.ActiveXObject("Microsoft.XMLDOM")) {
    parseXml = function(xmlStr) {
        var xmlDoc = new window.ActiveXObject("Microsoft.XMLDOM");
        xmlDoc.async = "false";
        xmlDoc.loadXML(xmlStr);
        return xmlDoc;
    };
} else {
    throw new Error("No XML parser found");
}

Example usage:

var xml = parseXml("<foo>Stuff</foo>");
alert(xml.documentElement.nodeName);

Which I got from https://mcmap.net/q/125843/-xml-parsing-of-a-variable-string-in-javascript.

Birdsong