Simple XPath Position

Create and evaluate simple XPath position expressions.

Installation

Using npm:

npm install simple-xpath-position

Usage

The module provides functions for describing and locating a DOM Node using an XPath expression.

API

fromNode(node, [root])

Convert a Node to an XPath expression.

If the optional parameter root is supplied, the computed XPath expression will be relative to it. Otherwise, the root of the document to which node belongs is used as the root.

Returns a string.

toNode(path, root, [resolver])

Locate a single Node that matches the given XPath expression. The XPath expressions are evaluated relative to the Node argument root.

If the optional parameter resolver is supplied, it will be used to resolve any namespaces within the XPath expression.

Returns a Node or null.

Compatibility

This library should work with any browser.

The presence of a working XPath evaluator is not strictly required. Without it, the library will only support XPath expressions that use a child axis and node names with number literal positions. All XPath expressions generated by this library fit this description. For instance, the library can generate and consume an expression such as /html/body/article/p[3].

For better XPath support, consider bundling an implementation such as the Wicked Good XPath library.

Internet Explorer version 8

• There is no support for namespaces in X(HT)ML documents.

Community

Originally, this code was part of the Annotator project.

Any discussion should happen on the annotator-dev mailing list.

Development

To contribute, fork this repository and send a pull request with your changes, including any necessary test and documentation updates.

Testing

You can run the command-line test suite by executing npm test.

To run the test suite, install the karma test runner with the command npm install -g karma-cli and then run karma start. Karma will print instructions for debugging the tests in a browser.