Parser for reading and writting XML formatted data

Jx.Store.Parser.XML.js

/*
---

name: Jx.Store.Parser.XML

description: Parser for reading and writting XML formatted data.

license: MIT-style license.

requires:
 - Jx.Store.Parser

provides: [Jx.Store.Parser.XML]

...
 */
// $Id$
/**
 * Class: Jx.Store.Parser.XML
 *
 * Extends: <Jx.Store.Parser>
 *
 * A Parser that handles encoding and decoding XML documents or strings
 *
 * License:
 * Copyright (c) 2012, Ing. Axel Mendoza.
 *
 * This file is licensed under an MIT style license
 */
Jx.Store.Parser.XML = new Class({

    Extends: Jx.Store.Parser,
    Family: "Jx.Store.Parser.XML",

    options: {
    	/**
         * Option: xpath
         * Set an xpath expression here to select the nodes you want to use for data retrieving
         */
		xpath: null,
		
		/**
         * Option: rootNodeText
         * Text of the root element in the generated xml string for encode function of this class
         */
		rootNodeText: 'data',
		
		/**
         * Option: everyNodeText
         * Text of every element under the root node in the generated xml string for encode function of this class
         */
		everyNodeText: 'item'
    },
    /**
     * APIMethod: parse
     * Turns a XML string or document into a JSON object if possible.
     *
     * Parameters:
     * data - the XML string or document representation of the data we're parsing
     */
    parse: function (data) {
    	var self = this;
        var type = Jx.type(data);
        var xmlDoc = null;
        if (type === 'string') {
        	if (window.DOMParser){
				xmlDoc = new DOMParser().parseFromString(data,"text/xml");
			}else{
				xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
				xmlDoc.async = false;
				xmlDoc.loadXML(data);
			}
        } else{
        	xmlDoc = data;
        }
        xmlDoc = xmlDoc.documentElement;
        if(this.options.xpath != null){
			if (window.DOMParser){
		    	var nodes = [];
				try {
				    var results = document.evaluate(this.options.xpath, xmlDoc, null, XPathResult.ANY_TYPE, null);
				    var node;
				    while (node = results.iterateNext()){
				        nodes.push(node);
			        }
				    xmlDoc = {childNodes: nodes};
				} catch (e) {
					return null;
				}
			} else{
        		xmlDoc = {childNodes: xmlDoc.selectNodes(this.options.xpath)};
    		}
        }
        return this.getNodes(xmlDoc);
    },

    /**
     * APIMethod: encode
     * Takes an object and turns it into XML.
     *
     * Parameters:
     * object - the object to encode
     */
    encode: function (object) {
        var data;
        if (object instanceof Jx.Record) {
            data = object.asObject();
        } else {
            data = object;
        }
		var xml = '<?xml version="1.0">';
		xml+= '<'+this.options.rootNodeText+'>'+this.getStringNode(object, this.options.everyNodeText)+'</'+this.options.rootNodeText+'>';
        return xml;
    },
    
    getStringNode: function(object, label){
    	var type = Jx.type(object);
    	var self = this;
    	var xml = '';
		if(type == 'object'){
			xml+='<'+label+'>';
			for(var prop in object){
				xml+=this.getStringNode(object[prop], prop);
			}
			xml+='</'+label+'>';
		} else if(type == 'string'){
			xml= '<'+label+'>'+object+'</'+label+'>';
		} else if(type == 'array'){
			Array.each(object, function(item){
				xml+= self.getStringNode(item, label);
			});
		}
		return xml;
    },
    
    getNodes: function(node){
    	if(node.childNodes.length != 0 && !(node.childNodes.length == 1 && node.childNodes[0].nodeType == 3)){
			var data = [];
			var self = this;
			Array.each(node.childNodes, function(child){
				var elem = {};
				Array.each(child.attributes, function(attr){
					elem[attr.name] = attr.value;
				});
				Array.each(child.childNodes, function(attr){
					if(elem[attr.nodeName] != undefined){
						if(Jx.type(elem[attr.nodeName]) == 'array'){
							elem[attr.nodeName].push(self.getNodes(attr));
						} else{
							elem[attr.nodeName] = [elem[attr.nodeName]];
						}
					}else{
						if(attr.nodeType == 3){
							elem['value'] = attr.textContent;
						} else{
							elem[attr.nodeName] = self.getNodes(attr);
						}
					}
				
				});
				data.push(elem);
			});
			return data;
		} else if(node.nodeType != 3 && node.attributes.length != 0){
			data = {};
			Array.each(node.attributes, function(attr){
				data[attr.name] = attr.value;
			});
			data['value'] = node.textContent;
			return data;
		} else {
			return node.textContent;
		}
	}
});