json.js

/*
 * jQuery JSON Plugin
 * version: 2.1 (2009-08-14)
 *
 * This document is licensed as free software under the terms of the
 * MIT License: http://www.opensource.org/licenses/mit-license.php
 *
 * Brantley Harris wrote this plugin. It is based somewhat on the JSON.org 
 * website's http://www.json.org/json2.js, which proclaims:
 * "NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.", a sentiment that
 * I uphold.
 *
 * It is also influenced heavily by MochiKit's serializeJSON, which is 
 * copyrighted 2005 by Bob Ippolito.
 */
//

steal('can/util', function (can) {
	/**
	 * @page can.toJSON
	 * @parent can.util
	 *
	 *     can.toJSON( json-serializble )
	 *
	 * Converts the given argument into a JSON respresentation.
	 *
	 * If an object has a "toJSON" function, that will
	 * be used to get the representation.
	 * Non-integer/string keys are skipped in the
	 * object, as are keys that point to a function.
	 *
	 * json-serializble:
	 * The *thing* to be converted.
	 */
	can.toJSON = function (o, replacer, space, recurse) {
		if (typeof(JSON) == 'object' && JSON.stringify)
			return JSON.stringify(o, replacer, space);

		if (!recurse && can.isFunction(replacer))
			o = replacer("", o);

		if (typeof space == "number")
			space = "          ".substring(0, space);
		space = (typeof space == "string") ? space.substring(0, 10) : "";

		var type = typeof(o);

		if (o === null)
			return "null";

		if (type == "undefined" || type == "function")
			return undefined;

		if (type == "number" || type == "boolean")
			return o + "";

		if (type == "string")
			return $.quoteString(o);

		if (type == 'object') {
			if (typeof o.toJSON == "function")
				return can.toJSON(o.toJSON(), replacer, space, true);

			if (o.constructor === Date) {
				var month = o.getUTCMonth() + 1;
				if (month < 10) month = '0' + month;

				var day = o.getUTCDate();
				if (day < 10) day = '0' + day;

				var year = o.getUTCFullYear();

				var hours = o.getUTCHours();
				if (hours < 10) hours = '0' + hours;

				var minutes = o.getUTCMinutes();
				if (minutes < 10) minutes = '0' + minutes;

				var seconds = o.getUTCSeconds();
				if (seconds < 10) seconds = '0' + seconds;

				var milli = o.getUTCMilliseconds();
				if (milli < 100) milli = '0' + milli;
				if (milli < 10) milli = '0' + milli;

				return '"' + year + '-' + month + '-' + day + 'T' +
					hours + ':' + minutes + ':' + seconds +
					'.' + milli + 'Z"';
			}

			var process = (can.isFunction(replacer)) ?
					function (k, v) {
						return replacer(k, v);
					} :
					function (k, v) {
						return v;
					},
				nl = (space) ? "\n" : "",
				sp = (space) ? " " : "";

			if (o.constructor === Array) {
				var ret = [];
				for (var i = 0; i < o.length; i++)
					ret.push(( can.toJSON(process(i, o[i]), replacer, space, true) || "null" ).replace(/^/gm, space));

				return "[" + nl + ret.join("," + nl) + nl + "]";
			}

			var pairs = [], proplist;
			if (can.isArray(replacer)) {
				proplist = can.map(replacer, function (v) {
					return (typeof v == "string" || typeof v == "number") ?
						v + "" :
						null;
				});
			}
			for (var k in o) {
				var name, val, type = typeof k;

				if (proplist && $.inArray(k + "", proplist) == -1)
					continue;

				if (type == "number")
					name = '"' + k + '"';
				else if (type == "string")
					name = $.quoteString(k);
				else
					continue;  //skip non-string or number keys

				val = can.toJSON(process(k, o[k]), replacer, space, true);

				if (typeof val == "undefined")
					continue;  //skip pairs where the value is a function.

				pairs.push((name + ":" + sp + val).replace(/^/gm, space));
			}

			return "{" + nl + pairs.join("," + nl) + nl + "}";
		}
	};

	/**
	 * @function can.evalJSON
	 * Evaluates a given piece of json source.
	 **/
	can.evalJSON = function (src) {
		if (typeof(JSON) == 'object' && JSON.parse)
			return JSON.parse(src);
		return eval("(" + src + ")");
	};

	/**
	 * @function can.secureEvalJSON
	 * Evals JSON in a way that is *more* secure.
	 **/
	can.secureEvalJSON = function (src) {
		if (typeof(JSON) == 'object' && JSON.parse)
			return JSON.parse(src);

		var filtered = src;
		filtered = filtered.replace(/\\["\\\/bfnrtu]/g, '@');
		filtered = filtered.replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']');
		filtered = filtered.replace(/(?:^|:|,)(?:\s*\[)+/g, '');

		if (/^[\],:{}\s]*$/.test(filtered))
			return eval("(" + src + ")");
		else
			throw new SyntaxError("Error parsing JSON, source is not valid.");
	};

	/**
	 * @function can.quoteString
	 *
	 * Returns a string-repr of a string, escaping quotes intelligently.
	 * Mostly a support function for toJSON.
	 *
	 * Examples:
	 *
	 *      can.quoteString("apple") //-> "apple"
	 *
	 *      can.quoteString('"Where are we going?", she asked.')
	 *        // -> "\"Where are we going?\", she asked."
	 **/
	can.quoteString = function (string) {
		if (string.match(_escapeable)) {
			return '"' + string.replace(_escapeable, function (a) {
				var c = _meta[a];
				if (typeof c === 'string') return c;
				c = a.charCodeAt();
				return '\\u00' + Math.floor(c / 16).toString(16) + (c % 16).toString(16);
			}) + '"';
		}
		return '"' + string + '"';
	};

	var _escapeable = /["\\\x00-\x1f\x7f-\x9f]/g;

	var _meta = {
		'\b' : '\\b',
		'\t' : '\\t',
		'\n' : '\\n',
		'\f' : '\\f',
		'\r' : '\\r',
		'"' : '\\"',
		'\\' : '\\\\'
	};

	return can;
})