xpath

DOM 3 XPath 1.0 implemention and helper for JavaScript, with node.js support.

Originally written by Cameron McCormack (blog).

Additional contributions from
Yaron Naveh (blog)
goto100
Thomas Weinert
Jimmy Rishe
and others

Install

Install with npm:

npm install xpath

xpath is xml engine agnostic but we recommend xmldom:

npm install @xmldom/xmldom

API Documentation

Can be found here. See below for example usage.

Your first xpath:

1var xpath = require('xpath');
2var dom = require('@xmldom/xmldom').DOMParser;
3
4var xml = "<book><title>Harry Potter</title></book>";
5var doc = new dom().parseFromString(xml, 'text/xml');
6var nodes = xpath.select("//title", doc);
7
8console.log(nodes[0].localName + ": " + nodes[0].firstChild.data);
9console.log("Node: " + nodes[0].toString());

➡

title: Harry Potter
Node: <title>Harry Potter</title>

Alternatively

Using the same interface you have on modern browsers (MDN)

1var node = null;
2var xml = "<book author='J. K. Rowling'><title>Harry Potter</title></book>";
3var doc = new dom().parseFromString(xml, 'text/xml');
4var result = xpath.evaluate(
5    "/book/title",            // xpathExpression
6    doc,                        // contextNode
7    null,                       // namespaceResolver
8    xpath.XPathResult.ANY_TYPE, // resultType
9    null                        // result
10);
11
12node = result.iterateNext();
13while (node) {
14    console.log(node.localName + ": " + node.firstChild.data);
15    console.log("Node: " + node.toString());
16
17    node = result.iterateNext();
18}

➡

title: Harry Potter
Node: <title>Harry Potter</title>

Evaluate string values directly:

1var xml = "<book><title>Harry Potter</title></book>";
2var doc = new dom().parseFromString(xml, 'text/xml');
3var title = xpath.select("string(//title)", doc);
4
5console.log(title);

➡

Harry Potter

Namespaces

1var xml = "<book><title xmlns='myns'>Harry Potter</title></book>";
2var doc = new dom().parseFromString(xml, 'text/xml');
3var node = xpath.select("//*[local-name(.)='title' and namespace-uri(.)='myns']", doc)[0];
4
5console.log(node.namespaceURI);

➡

myns

Namespaces with easy mappings

1var xml = "<book xmlns:bookml='http://example.com/book'><bookml:title>Harry Potter</bookml:title></book>"
2var select = xpath.useNamespaces({"bookml": "http://example.com/book"});
3
4console.log(select('//bookml:title/text()', doc)[0].nodeValue);

➡

Harry Potter

Default namespace with mapping

1var xml = "<book xmlns='http://example.com/book'><title>Harry Potter</title></book>"
2var select = xpath.useNamespaces({"bookml": "http://example.com/book"});
3
4console.log(select('//bookml:title/text()', doc)[0].nodeValue);

➡

Harry Potter

Attributes

1var xml = "<book author='J. K. Rowling'><title>Harry Potter</title></book>";
2var doc = new dom().parseFromString(xml, 'text/xml');
3var author = xpath.select1("/book/@author", doc).value;
4
5console.log(author);

➡

J. K. Rowling

License

MIT