יום חמישי, 2 ביוני 2011

הפיכת XML ל - JSON

דינוזאורים עדיין עובדים על XML בכל מיני מקומות לצערי. זה נכון XML נותן הרבה יותר יכולות ש - JSON לא, אבל עדיין, JSON זה פשוט כיף.

לעיתים אנחנו נתקלים בצורך להמיר XML ל - JSON מתוך JavaScript, כמו לדוגמא בשימוש בתוך Firefox Extension או קריאות Ajax ו - XSS Cross Sites ּScripting.

ישנן הרבה ספריות ברשת להמרת XML ל - JSON רק חלקן ב - JavaScript ורובן לא עובדות.
מצאתי אחת שכן עובדת:
http://michael.hinnerup.net/blog/wp-content/uploads/2008/01/JsonXml.js
http://michael.hinnerup.net/blog/2008/01/26/converting-json-to-xml-and-xml-to-json/



/*
The below work is licensed under Creative Commons GNU LGPL License.

Original work:

License: http://creativecommons.org/licenses/LGPL/2.1/
Author: Stefan Goessner/2006
Web: http://goessner.net/

Modifications made:

Version: 0.9-p5
Description: Restructured code, JSLint validated (no strict whitespaces),
added handling of empty arrays, empty strings, and int/floats values.
Author: Michael Schøler/2008-01-29
Web: http://michael.hinnerup.net/blog/2008/01/26/converting-json-to-xml-and-xml-to-json/
*/

/*global alert */
var xmlJsonClass = {
// Param "xml": Element or document DOM node.
// Param "tab": Tab or indent string for pretty output formatting omit or use empty string "" to supress.
// Returns: JSON string
xml2json: function(xml, tab) {
if (xml.nodeType === 9) {
// document node
xml = xml.documentElement;
}
var nws = this.removeWhite(xml);
var obj = this.toObj(nws);
var json = this.toJson(obj, xml.nodeName, "\t");
return "{\n" + tab + (tab ? json.replace(/\t/g, tab) : json.replace(/\t|\n/g, "")) + "\n}";
},

// Param "o": JavaScript object
// Param "tab": tab or indent string for pretty output formatting omit or use empty string "" to supress.
// Returns: XML string
json2xml: function(o, tab) {
var toXml = function(v, name, ind) {
var xml = "";
var i, n;
if (v instanceof Array) {
if (v.length === 0) {
xml += ind + "<"+name+">__EMPTY_ARRAY_\n";
}
else {
for (i = 0, n = v.length; i < n; i += 1) {
var sXml = ind + toXml(v[i], name, ind+"\t") + "\n";
xml += sXml;
}
}
}
else if (typeof(v) === "object") {
var hasChild = false;
xml += ind + "<" + name;
var m;
for (m in v) if (v.hasOwnProperty(m)) {
if (m.charAt(0) === "@") {
xml += " " + m.substr(1) + "=\"" + v[m].toString() + "\"";
}
else {
hasChild = true;
}
}
xml += hasChild ? ">" : "/>";
if (hasChild) {
for (m in v) if (v.hasOwnProperty(m)) {
if (m === "#text") {
xml += v[m];
}
else if (m === "#cdata") {
xml += "";
}
else if (m.charAt(0) !== "@") {
xml += toXml(v[m], m, ind+"\t");
}
}
xml += (xml.charAt(xml.length - 1) === "\n" ? ind : "") + "";
}
}
else {
if (v.toString() === "\"\"" || v.toString().length === 0) {
xml += ind + "<" + name + ">__EMPTY_STRING_";
}
else {
xml += ind + "<" + name + ">" + v.toString() + "";
}
}
return xml;
};
var xml = "";
var m;
for (m in o) if (o.hasOwnProperty(m)) {
xml += toXml(o[m], m, "");
}
return tab ? xml.replace(/\t/g, tab) : xml.replace(/\t|\n/g, "");
},

// Internal methods
toObj: function(xml) {
var o = {};
if (xml.nodeType === 1) {
// element node ..
if (xml.attributes.length) {
// element with attributes ..
var i;
for (i = 0; i < xml.attributes.length; i += 1) {
o["@" + xml.attributes[i].nodeName] = (xml.attributes[i].nodeValue || "").toString();
}
}
if (xml.firstChild) {
// element has child nodes ..
var textChild = 0, cdataChild = 0, hasElementChild = false;
var n;
for (n = xml.firstChild; n; n = n.nextSibling) {
if (n.nodeType === 1) {
hasElementChild = true;
}
else if (n.nodeType === 3 && n.nodeValue.match(/[^ \f\n\r\t\v]/)) {
// non-whitespace text
textChild += 1;
}
else if (n.nodeType === 4) {
// cdata section node
cdataChild += 1;
}
}
if (hasElementChild) {
if (textChild < 2 && cdataChild < 2) {
// structured element with evtl. a single text or/and cdata node ..
this.removeWhite(xml);
for (n = xml.firstChild; n; n = n.nextSibling) {
if (n.nodeType === 3) {
// text node
o["#text"] = this.escape(n.nodeValue);
}
else if (n.nodeType === 4) {
// cdata node
o["#cdata"] = this.escape(n.nodeValue);
}
else if (o[n.nodeName]) {
// multiple occurence of element ..
if (o[n.nodeName] instanceof Array) {
o[n.nodeName][o[n.nodeName].length] = this.toObj(n);
}
else {
o[n.nodeName] = [o[n.nodeName], this.toObj(n)];
}
}
else {
// first occurence of element ..
o[n.nodeName] = this.toObj(n);
}
}
}
else {
// mixed content
if (!xml.attributes.length) {
o = this.escape(this.innerXml(xml));
}
else {
o["#text"] = this.escape(this.innerXml(xml));
}
}
}
else if (textChild) {
// pure text
if (!xml.attributes.length) {
o = this.escape(this.innerXml(xml));
if (o === "__EMPTY_ARRAY_") {
o = "[]";
} else if (o === "__EMPTY_STRING_") {
o = "";
}
}
else {
o["#text"] = this.escape(this.innerXml(xml));
}
}
else if (cdataChild) {
// cdata
if (cdataChild > 1) {
o = this.escape(this.innerXml(xml));
}
else {
for (n = xml.firstChild; n; n = n.nextSibling) {
o["#cdata"] = this.escape(n.nodeValue);
}
}
}
}
if (!xml.attributes.length && !xml.firstChild) {
o = null;
}
}
else if (xml.nodeType === 9) {
// document.node
o = this.toObj(xml.documentElement);
}
else {
alert("unhandled node type: " + xml.nodeType);
}
return o;
},
toJson: function(o, name, ind) {
var json = name ? ("\"" + name + "\"") : "";
if (o === "[]") {
json += (name ? ":[]" : "[]");
}
else if (o instanceof Array) {
var n, i;
for (i = 0, n = o.length; i < n; i += 1) {
o[i] = this.toJson(o[i], "", ind + "\t");
}
json += (name ? ":[" : "[") + (o.length > 1 ? ("\n" + ind + "\t" + o.join(",\n" + ind + "\t") + "\n" + ind) : o.join("")) + "]";
}
else if (o === null) {
json += (name && ":") + "null";
}
else if (typeof(o) === "object") {
var arr = [];
var m;
for (m in o) if (o.hasOwnProperty(m)) {
arr[arr.length] = this.toJson(o[m], m, ind + "\t");
}
json += (name ? ":{" : "{") + (arr.length > 1 ? ("\n" + ind + "\t" + arr.join(",\n" + ind + "\t") + "\n" + ind) : arr.join("")) + "}";
}
else if (typeof(o) === "string") {
o = o.toString();
var objRegExp = /(^-?\d+\.?\d*$)/;
if (objRegExp.test(o)) {
// int or float
json += (name && ":") + o;
}
else {
json += (name && ":") + "\"" + o + "\"";
}
}
else {
json += (name && ":") + o.toString();
}
return json;
},
innerXml: function(node) {
var s = "";
if ("innerHTML" in node) {
s = node.innerHTML;
}
else {
var asXml = function(n) {
var s = "", i;
if (n.nodeType === 1) {
s += "<" + n.nodeName;
for (i = 0; i < n.attributes.length; i += 1) {
s += " " + n.attributes[i].nodeName + "=\"" + (n.attributes[i].nodeValue || "").toString() + "\"";
}
if (n.firstChild) {
s += ">";
for (var c = n.firstChild; c; c = c.nextSibling) {
s += asXml(c);
}
s += "";
}
else {
s += "/>";
}
}
else if (n.nodeType === 3) {
s += n.nodeValue;
}
else if (n.nodeType === 4) {
s += "";
}
return s;
};
for (var c = node.firstChild; c; c = c.nextSibling) {
s += asXml(c);
}
}
return s;
},
escape: function(txt) {
return txt.replace(/[\\]/g, "\\\\").replace(/[\"]/g, '\\"').replace(/[\n]/g, '\\n').replace(/[\r]/g, '\\r');
},
removeWhite: function(e) {
e.normalize();
var n;
for (n = e.firstChild; n; ) {
if (n.nodeType === 3) {
// text node
if (!n.nodeValue.match(/[^ \f\n\r\t\v]/)) {
// pure whitespace text node
var nxt = n.nextSibling;
e.removeChild(n);
n = nxt;
}
else {
n = n.nextSibling;
}
}
else if (n.nodeType === 1) {
// element node
this.removeWhite(n);
n = n.nextSibling;
}
else {
// any other node
n = n.nextSibling;
}
}
return e;
}
};