Selecting xml node by attribute id

My aim is simple, I just need to get the value by an attrbiute. For example consider this xml:

<?xml version="1.0" encoding="UTF-8"?>
<preferences>
    <custom-preferences>
        <staging>
             <preference preference-id="foo">true</preference>
             <preference preference-id="bar">true</preference>
        </staging>
    <custom-preferences>
<preferences>
</xml>

The xml is in a file, this is what I have so far:

var fs = require('fs'),
xml2js = require('xml2js');
 
var parser = new xml2js.Parser();
fs.readFile(pref, function(err, data) {parser.parseString(data, function (err, result) {

    console.log(result.preferences['custom-preferences'][0].staging[0].preference[0]);

    });
});

So if I hard code the index it will work, but can I select the node where preference-id = foo or bar etc.

I'm trying to avoid reading the parent node and performing a for each. I am happy and willing to use other package or libraries if it will help me to achieve the goal.

Solution

It is possible by jsdom or xml.etree.ElementTree

Code by node.js

const jsdom = require("jsdom");

const response = `
<?xml version="1.0" encoding="UTF-8"?>
<preferences>
    <custom-preferences>
        <staging>
             <preference preference-id="foo">true</preference>
             <preference preference-id="bar">true</preference>
        </staging>
    </custom-preferences>
</preferences>`

const dom = new jsdom.JSDOM(response);
console.log('foo: '   + dom.window.document.querySelector('[preference-id="foo"]').textContent)
console.log('bar: '   + dom.window.document.querySelector('[preference-id="bar"]').textContent)

Result

$ node find-attribute.js
foo: true
bar: true

Code by Python

import xml.etree.ElementTree as ET
document = """\
<?xml version="1.0" encoding="UTF-8"?>
<preferences>
    <custom-preferences>
        <staging>
             <preference preference-id="foo">true</preference>
             <preference preference-id="bar">true</preference>
        </staging>
    </custom-preferences>
</preferences>
"""

root = ET.fromstring(document)
print("preference-id='foo' " + root.find(".//*[@preference-id='foo']").text)
print("preference-id='bar' " + root.find(".//*[@preference-id='bar']").text)

Result

$ python find-attribute.py
preference-id='foo' true
preference-id='bar' true