## xpath
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DOM 3 XPath 1.0 implemention and helper for JavaScript, with node.js support.
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Originally written by Cameron McCormack ([blog](http://mcc.id.au/xpathjs)).
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Additional contributions from
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Yaron Naveh ([blog](http://webservices20.blogspot.com/))
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goto100
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Thomas Weinert
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Jimmy Rishe
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and [others](https://github.com/goto100/xpath/graphs/contributors)
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## Install
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Install with [npm](http://github.com/isaacs/npm):
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npm install xpath
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xpath is xml engine agnostic but I recommend to use [xmldom](https://github.com/jindw/xmldom):
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npm install xmldom
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## API Documentation
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Can be found [here](https://github.com/goto100/xpath/blob/master/docs/xpath%20methods.md). See below for example usage.
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## Your first xpath:
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`````javascript
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var xpath = require('xpath')
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, dom = require('xmldom').DOMParser
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var xml = "<book><title>Harry Potter</title></book>"
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var doc = new dom().parseFromString(xml)
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var nodes = xpath.select("//title", doc)
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console.log(nodes[0].localName + ": " + nodes[0].firstChild.data)
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console.log("Node: " + nodes[0].toString())
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`````
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➡
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title: Harry Potter
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Node: <title>Harry Potter</title>
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### Alternatively
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Using the same interface you have on modern browsers ([MDN])
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`````javascript
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var node = null;
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var xml = "<book author='J. K. Rowling'><title>Harry Potter</title></book>"
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var doc = new dom().parseFromString(xml)
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var result = xpath.evaluate(
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"/book/title", // xpathExpression
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doc, // contextNode
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null, // namespaceResolver
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xpath.XPathResult.ANY_TYPE, // resultType
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null // result
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)
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node = result.iterateNext();
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while (node) {
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console.log(node.localName + ": " + node.firstChild.data);
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console.log("Node: " + node.toString());
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node = result.iterateNext();
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}
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`````
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➡
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title: Harry Potter
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Node: <title>Harry Potter</title>
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## Evaluate string values directly:
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`````javascript
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var xml = "<book><title>Harry Potter</title></book>";
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var doc = new dom().parseFromString(xml);
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var title = xpath.select("string(//title)", doc);
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console.log(title);
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`````
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➡
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Harry Potter
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## Namespaces
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`````javascript
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var xml = "<book><title xmlns='myns'>Harry Potter</title></book>"
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var doc = new dom().parseFromString(xml)
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var node = xpath.select("//*[local-name(.)='title' and namespace-uri(.)='myns']", doc)[0]
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console.log(node.namespaceURI)
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`````
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➡
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myns
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## Namespaces with easy mappings
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`````javascript
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var xml = "<book xmlns:bookml='http://example.com/book'><bookml:title>Harry Potter</bookml:title></book>"
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var select = xpath.useNamespaces({"bookml": "http://example.com/book"});
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console.log(select('//bookml:title/text()', doc)[0].nodeValue);
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`````
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➡
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Harry Potter
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## Default namespace with mapping
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`````javascript
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var xml = "<book xmlns='http://example.com/book'><title>Harry Potter</title></book>"
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var select = xpath.useNamespaces({"bookml": "http://example.com/book"});
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console.log(select('//bookml:title/text()', doc)[0].nodeValue);
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`````
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➡
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Harry Potter
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## Attributes
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`````javascript
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var xml = "<book author='J. K. Rowling'><title>Harry Potter</title></book>"
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var doc = new dom().parseFromString(xml)
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var author = xpath.select1("/book/@author", doc).value
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console.log(author)
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`````
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➡
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J. K. Rowling
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[MDN]: https://developer.mozilla.org/en/docs/Web/API/Document/evaluate
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## License
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MIT
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