parsing XML in JavaScript, trying to get elements by classname

Question

I am trying to parse a large XML file using JavaScript. Looking online, it seems that the easiest way to start is to use the browser's DOM parser. This works, and I can get elements by ID. I can also get the "class" attribute for those elements, and it returns what I would expect. However, I don't appear to be able to get elements by class.

The following was tried in the latest Chrome:

xmlString = '<?xml version="1.0"?>';
xmlString = xmlString + '<example class="test" id="example">content</example>'

parser = new DOMParser();
xmlDoc = parser.parseFromString(xmlString,"text/xml");

xmlDoc.getElementById("example");    
      // returns the example element (good)

xmlDoc.getElementById("example").getAttribute("class");
      // returns "test" (good)

xmlDoc.getElementsByClassName("test");
      // returns [] (bad)

Any ideas?

Which browser? maybe your browser doesn't support this function? — gdoron, May 08 '12 at 17:55
possible duplicate to http://stackoverflow.com/questions/9396354 — Bergi, May 08 '12 at 17:58
This will not work, as you are dealing with an XML document, and HTML-specific properties (like `class`) don't apply. However, you can still get elements by tag name, (i.e. `xmlDoc.getElementsByTagName('example');`) - could you perhaps use this to your advantage? — Jim O'Brien, May 08 '12 at 17:59
ID and ClassName are data types, and in an XML document they are not valid. — adeneo, May 08 '12 at 18:02

score 1 · Answer 1 · edited May 08 '12 at 19:28

1

This should get all elements of a given class, assuming that the tag name will be consistent.

var elements = xmlDoc.getElementsByTagName('Example');
var classArray = [];
for(var i=0;i<elements.length;i++){
    if(elements[i].className=="test"){
        classArray.push(elements[i])
}}

edited May 08 '12 at 19:28

DaveShaw

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answered May 08 '12 at 18:09

empire1138

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That almost works, except .className doesn't exist, at least in Chrome, so you have to use getAttribute('class'). I don't know if it's faster than the jQuery parser, though – Sam Fen May 08 '12 at 18:52

score 0 · Accepted Answer · answered May 08 '12 at 18:02

0

You can use JQuery to parse an XML file by using a class selector. http://jquery.com

answered May 08 '12 at 18:02

marteljn

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ok, it looks like that's the best way if jQuery is available. Thanks. – Sam Fen May 08 '12 at 18:11

score 0 · Answer 3 · answered Dec 30 '16 at 00:47

0

Updating the parser type to HTML as opposed to XML should work.

parser = new DOMParser();
xmlDoc = parser.parseFromString(xmlString,"text/html")

answered Dec 30 '16 at 00:47

boxbit

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parsing XML in JavaScript, trying to get elements by classname

3 Answers3