json2xml NodeJS Module - Convert an xml2js JSON object back to XML

json2xml.js

/**
 *	json2xml NodeJS Module - Convert an xml2js JSON object back to XML
 *	
 *	Redsandro - changed into requirable
 *	
 *	@author Derek Anderson
 *	@copyright 2011 Media Upstream
 *	@license MIT License
 *	@url https://gist.github.com/1495793
 *
 *	Usage:
 *			json2xml = require('./json2xml').json2xml;
 *
 *			json2xml({"jsonObject": "@": { "attribute": "value", "foo": "bar" }}, "rootElement", function(xml) {
 *				console.log(xml); // log the XML data
 *			});		
 *
 * License
 * -------
 * 
 * Copyright (c) 2011 Derek Anderson / Media Upstream
 * https://gist.github.com/1495793
 * 
 * Copyright (c) 2012 Redsandro - Turned into NodeJS Module
 * http://www.redsandro.com/
 * 
 * The MIT License (MIT)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining 
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included 
 * in all copies or substantial portions of the Software.
 */



exports.json2xml = function(json, root, cb){
	var recursion = 0;
	var xml = '<?xml version="1.0" ?>';
	var isArray = function(obj) { return obj.constructor == Array; };
	
	var parseAttributes = function(node){
		for(key in node){
			var value = node[key];
			xml += ' ' + key +'="'+ value +'"';
		};
	xml += '>';
	};
	
	var parseNode = function(node, parentNode){
		recursion++;
		// Handle Object structures in the JSON properly
		if(!isArray(node)){
			xml += '<'+ parentNode;
			if(typeof node == 'object' && node['@']){
				parseAttributes(node['@']);
			} else {
				xml += '>';
			}
			for(key in node){
				var value = node[key];
				// text values
				if(typeof value == 'string'){
					if(key === '#'){
						xml += value;
					} else {
						xml += '<'+ key +'>'+ value + '</'+key+'>';
					}
				}
				// is an object
				if(typeof value == 'object' && key != '@'){
					parseNode(node[key], key);
				}
			}
			recursion--;
			xml += '</'+ parentNode +'>';
		}
		
		// Handle array structures in the JSON properly
		if(isArray(node)){
			for(var i=0; i < node.length; i++){
				parseNode(node[i], parentNode);
			}
			recursion--;
		}
		
		if (recursion === 0) { cb(xml); }
	};
	parseNode(json, root); // fire up the parser!
};

The example does not work with node.js.
The JSON object is invalid in that case, with valid JSON there is no way to add attributes to a node.

This does work with node.js and it is proper json.
As you can see, attributes are added in a key called '@'.

There is a curly bracket missing, the proper notation for the JSON object is {"jsonObject": {"@": { "attribute": "value", "foo": "bar" }}}

Looks like it doesn't work right with arrays :(

 in {"trk":{"trkseg":[{"trkpt":{"time":9}},{"trkpt":{"time":0}}]}}
 out <?xml version="1.0" ?><gpx><trk><trkseg><trkpt></trkpt></trkseg><trkseg><trkpt></trkpt></trkseg></trk></gpx>

Hey @ql - sorry I hadn't seen this message. I just borrowed someone's code and node-ified it. Worked for my purposes.

Of course a bit further down the journey, we are better off just like to use someone's npm package. There is however some choice, and there's no clear winner.

• https://github.com/oozcitak/xmlbuilder-js
• https://github.com/estheban/node-json2xml
• https://github.com/dylang/node-xml
• https://github.com/chilts/data2xml
• https://github.com/davidcalhoun/jstoxml
• https://github.com/soldair/node-jsontoxml
• https://github.com/tlhunter/node-easyxml
• https://github.com/michaelkourlas/node-js2xmlparser

This one is just not very nicely written imo, and has some non-versatile tricks like removing the s from array keys.

• https://github.com/tlhunter/node-easyxml

We should probably remove the ones that cannot easily convert an object to xml attributes without renaming all the keys.

• https://github.com/oozcitak/xmlbuilder-js

Now these modules allow for multiple root elements, which is not allowed in XML, so I don't trust these are mature modules:

• https://github.com/estheban/node-json2xml
• https://github.com/dylang/node-xml
• https://github.com/davidcalhoun/jstoxml

So we have three left that make sense. However none of the mentioned modules call back. They are all blocking. I should strike out these too for that, but we'll have nothing left.

• https://github.com/chilts/data2xml
• https://github.com/soldair/node-jsontoxml
• https://github.com/michaelkourlas/node-js2xmlparser

What is your opinion? What do you use these days for your JSON to XML needs?