libxml-to-js

About

This is a XML to JavaScript object parser. It uses the libxmljs module for the actual XML parsing. It aims to be an easy xml2js v1 replacement, but it doesn't follow the xml2js API.

libxml-to-js uses the string parser method of libxmljs. Basically a modified version of the algorithm from here in order to fit the formal specifications of xml2js output.

Installation

npm install libxml-to-js

The installation of the underlying dependency, libxmljs, fails if you don't have gcc (or compatible compiler), the libxml2 development headers, and the xml2-config script. Under various Linux distributions you may install the appropriate libxml2 development package: libxml2-dev (Debian, Ubuntu, etc), libxml2-devel (RHEL, CentOS, Fedora, etc).

Usage mode

var parser = require('libxml-to-js');
var xml = 'xml string';

parser(xml, function (error, result) {
  if (error) {
    console.error(error);
  } else {
    console.log(result);
  }
});

With XPath query:

parser(xml, '//xpath/query', function (error, result) {
  if (error) {
    console.error(error);
  } else {
    console.log(result);
  }
});

Gotcha

Due to the fact that libxmljs does not have any method for returning the namespace attributes of a specific element, the returned namespaces aren't returned as expected:

• the returned namespaces are only the actual used namespaces by the XML document. If there are unused namespaces, they aren't returned. This is a consequence of the fact that the namespaces are pushed into the returned object as they are detected by the parsing recursion.
• the returned namespaces are attached as attributes to the root element, into the xmlns key in order to keep the code simple.

Example from the WordPress RSS 2 feed:

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0"
  xmlns:content="http://purl.org/rss/1.0/modules/content/"
  xmlns:wfw="http://wellformedweb.org/CommentAPI/"
  xmlns:dc="http://purl.org/dc/elements/1.1/"
  xmlns:atom="http://www.w3.org/2005/Atom"
  xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
  xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
  >
<!-- the rest of the doc -->
</rss>

is parsed as:

{ '@':
  { version: '2.0',
    xmlns:
      { atom: 'http://www.w3.org/2005/Atom',
        sy: 'http://purl.org/rss/1.0/modules/syndication/',
        dc: 'http://purl.org/dc/elements/1.1/',
        content: 'http://purl.org/rss/1.0/modules/content/',
        wfw: 'http://wellformedweb.org/CommentAPI/',
        slash: 'http://purl.org/rss/1.0/modules/slash/' } },
// the rest of the doc
}

Contributors

• @Brian White: The original algorithm for converting a parsed XML doc into JavaScript object.
• @Marsup: XPath queries support.
• @VirgileD: improved text kludge and namespaces support
• @Richard Anaya: fix for #6
• @TokyoIncidents: fixes a couple of global variables leaks #10
• @XApp-Studio: more support for CDATA elements #13