Harry Potter

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:

````

javascript

var xpath = require('xpath');

var dom = require('@xmldom/xmldom').DOMParser;



var xml = "Harry Potter";

var doc = new dom().parseFromString(xml, 'text/xml');

var nodes = xpath.select("//title", doc);



console.log(nodes[0].localName + ": " + nodes[0].firstChild.data);

console.log("Node: " + nodes[0].toString());

```



➡



    title: Harry Potter

    Node: Harry Potter



$3



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

```

javascript

var node = null;

var xml = "Harry Potter";

var doc = new dom().parseFromString(xml, 'text/xml');

var result = xpath.evaluate(

    "/book/title",            // xpathExpression

    doc,                        // contextNode

    null,                       // namespaceResolver

    xpath.XPathResult.ANY_TYPE, // resultType

    null                        // result

);



node = result.iterateNext();

while (node) {

    console.log(node.localName + ": " + node.firstChild.data);

    console.log("Node: " + node.toString());



    node = result.iterateNext();

}

```



➡



    title: Harry Potter

    Node: Harry Potter



Evaluate string values directly:

```

javascript

var xml = "Harry Potter";

var doc = new dom().parseFromString(xml, 'text/xml');

var title = xpath.select("string(//title)", doc);



console.log(title);

```



➡



    Harry Potter



Namespaces

```

javascript

var xml = "Harry Potter";

var doc = new dom().parseFromString(xml, 'text/xml');

var node = xpath.select("//*[local-name(.)='title' and namespace-uri(.)='myns']", doc)[0];



console.log(node.namespaceURI);

```



➡



    myns



Namespaces with easy mappings

```

javascript

var xml = "Harry Potter"

var select = xpath.useNamespaces({"bookml": "http://example.com/book"});



console.log(select('//bookml:title/text()', doc)[0].nodeValue);

```



➡



    Harry Potter



Default namespace with mapping

```

javascript

var xml = "Harry Potter"

var select = xpath.useNamespaces({"bookml": "http://example.com/book"});



console.log(select('//bookml:title/text()', doc)[0].nodeValue);

```



➡



    Harry Potter



Attributes

```

javascript

var xml = "Harry Potter";

var doc = new dom().parseFromString(xml, 'text/xml');

var author = xpath.select1("/book/@author", doc).value;



console.log(author);

````
➡

J. K. Rowling

[MDN]: https://developer.mozilla.org/en/docs/Web/API/Document/evaluate

License

MIT