2 Copyright (c) 2009, Yahoo! Inc. All rights reserved.
3 Code licensed under the BSD License:
4 http://developer.yahoo.net/yui/license.txt
8 YUI.add('json-parse', function(Y) {
11 * <p>The JSON module adds support for serializing JavaScript objects into
12 * JSON strings and parsing JavaScript objects from strings in JSON format.</p>
14 * <p>The JSON namespace is added to your YUI instance including static methods
15 * Y.JSON.parse(..) and Y.JSON.stringify(..).</p>
17 * <p>The functionality and method signatures follow the ECMAScript 5
18 * specification. In browsers with native JSON support, the native
19 * implementation is used.</p>
21 * <p>The <code>json</code> module is a rollup of <code>json-parse</code> and
22 * <code>json-stringify</code>.</p>
24 * <p>As their names suggest, <code>json-parse</code> adds support for parsing
25 * JSON data (Y.JSON.parse) and <code>json-stringify</code> for serializing
26 * JavaScript data into JSON strings (Y.JSON.stringify). You may choose to
27 * include either of the submodules individually if you don't need the
28 * complementary functionality, or include the rollup for both.</p>
36 * Provides Y.JSON.parse method to accept JSON strings and return native
40 * @submodule json-parse
46 // All internals kept private for security reasons
50 * Alias to native browser implementation of the JSON object if available.
56 var _JSON = Y.config.win.JSON,
57 Native = (Object.prototype.toString.call(_JSON) === '[object JSON]' && _JSON),
60 * Replace certain Unicode characters that JavaScript may handle incorrectly
61 * during eval--either by deleting them or treating them as line
62 * endings--with escape sequences.
63 * IMPORTANT NOTE: This regex will be used to modify the input if a match is
66 * @property _UNICODE_EXCEPTIONS
70 _UNICODE_EXCEPTIONS = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
74 * First step in the safety evaluation. Regex used to replace all escape
75 * sequences (i.e. "\\", etc) with '@' characters (a non-JSON character).
81 _ESCAPES = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,
84 * Second step in the safety evaluation. Regex used to replace all simple
85 * values with ']' characters.
91 _VALUES = /"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,
94 * Third step in the safety evaluation. Regex used to remove all open
95 * square brackets following a colon, comma, or at the beginning of the
102 _BRACKETS = /(?:^|:|,)(?:\s*\[)+/g,
105 * Final step in the safety evaluation. Regex used to test the string left
106 * after all previous replacements for invalid characters.
112 _UNSAFE = /[^\],:{}\s]/,
115 * Replaces specific unicode characters with their appropriate \unnnn
116 * format. Some browsers ignore certain characters during eval.
118 * @method escapeException
119 * @param c {String} Unicode character
120 * @return {String} the \unnnn escapement of the character
123 _escapeException = function (c) {
124 return '\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
128 * Traverses nested objects, applying a reviver function to each (key,value)
129 * from the scope if the key:value's containing object. The value returned
130 * from the function will replace the original value in the key:value pair.
131 * If the value returned is undefined, the key will be omitted from the
135 * @param data {MIXED} Any JavaScript data
136 * @param reviver {Function} filter or mutation function
137 * @return {MIXED} The results of the filtered data
140 _revive = function (data, reviver) {
141 var walk = function (o,key) {
142 var k,v,value = o[key];
143 if (value && typeof value === 'object') {
145 if (value.hasOwnProperty(k)) {
147 if (v === undefined) {
155 return reviver.call(o,key,value);
158 return typeof reviver === 'function' ? walk({'':data},'') : data;
162 * Parse a JSON string, returning the native JavaScript representation.
164 * @param s {string} JSON string data
165 * @param reviver {function} (optional) function(k,v) passed each key value
166 * pair of object literals, allowing pruning or altering values
167 * @return {MIXED} the native JavaScript representation of the JSON string
168 * @throws SyntaxError
172 // JavaScript implementation in lieu of native browser support. Based on
173 // the json2.js library from http://json.org
174 _parse = function (s,reviver) {
175 if (typeof s === 'string') {
176 // Replace certain Unicode characters that are otherwise handled
177 // incorrectly by some browser implementations.
178 // NOTE: This modifies the input if such characters are found!
179 s = s.replace(_UNICODE_EXCEPTIONS, _escapeException);
181 // Test for any remaining invalid characters
182 if (!_UNSAFE.test(s.replace(_ESCAPES,'@').
183 replace(_VALUES,']').
184 replace(_BRACKETS,''))) {
186 // Eval the text into a JavaScript data structure, apply any
187 // reviver function, and return
188 return _revive( eval('(' + s + ')'), reviver );
192 throw new SyntaxError('JSON.parse');
195 Y.namespace('JSON').parse = function (s,reviver) {
196 return Native && Y.JSON.useNativeParse ?
197 Native.parse(s,reviver) : _parse(s,reviver);
201 * Leverage native JSON parse if the browser has a native implementation.
202 * In general, this is a good idea. See the Known Issues section in the
203 * JSON user guide for caveats. The default value is true for browsers with
204 * native JSON support.
206 * @property useNativeParse
211 Y.JSON.useNativeParse = !!Native;
215 YUI.add('json-stringify', function(Y) {
218 * Provides Y.JSON.stringify method for converting objects to JSON strings.
221 * @submodule json-stringify
225 var _JSON = Y.config.win.JSON,
227 isFunction= Lang.isFunction,
228 isObject = Lang.isObject,
229 isArray = Lang.isArray,
230 _toStr = Object.prototype.toString,
231 Native = (_toStr.call(_JSON) === '[object JSON]' && _JSON),
232 UNDEFINED = 'undefined',
240 'undefined' : UNDEFINED,
242 '[object String]' : STRING,
244 '[object Number]' : NUMBER,
246 '[object Boolean]' : BOOLEAN,
247 '[object Date]' : DATE,
248 '[object RegExp]' : OBJECT
261 // Regex used to capture characters that need escaping before enclosing
262 // their containing string in quotes.
263 _SPECIAL_CHARS = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
264 // Character substitution map for common escapes and special characters.
276 // Utility function used to determine how to serialize a variable.
279 return _allowable[t] || // number, string, boolean, undefined
280 _allowable[_toStr.call(o)] || // Number, String, Boolean, Date
282 (o ? OBJECT : NULL) : // object, array, null, misc natives
283 UNDEFINED); // function, unknown
286 // Escapes a special character to a safe Unicode representation
289 _CHARS[c] = '\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
294 // Enclose escaped strings in quotes
295 function _string(s) {
296 return QUOTE + s.replace(_SPECIAL_CHARS, _char) + QUOTE;
299 // Adds the provided space to the beginning of every line in the input string
300 function _indent(s,space) {
301 return s.replace(/^/gm, space);
304 // JavaScript implementation of stringify (see API declaration of stringify)
305 function _stringify(o,w,space) {
306 if (o === undefined) {
310 var replacer = isFunction(w) ? w : null,
311 format = _toStr.call(space).match(/String|Number/) || [],
312 _date = Y.JSON.dateToString,
316 if (replacer || !isArray(w)) {
320 // Ensure whitelist keys are unique (bug 2110391)
323 for (i = 0, len = w.length; i < len; ++i) {
329 // Per the spec, strings are truncated to 10 characters and numbers
330 // are converted to that number of spaces (max 10)
331 space = format[0] === 'Number' ?
332 new Array(Math.min(Math.max(0,space),10)+1).join(" ") :
333 (space || EMPTY).slice(0,10);
335 function _serialize(h,key) {
339 colon = space ? COLON_SP : COLON,
342 // Per the ECMA 5 spec, toJSON is applied before the replacer is
343 // called. Also per the spec, Date.prototype.toJSON has been added, so
344 // Date instances should be serialized prior to exposure to the
345 // replacer. I disagree with this decision, but the spec is the spec.
346 if (isObject(value) && isFunction(value.toJSON)) {
347 value = value.toJSON(key);
348 } else if (t === DATE) {
349 value = _date(value);
352 if (isFunction(replacer)) {
353 value = replacer.call(h,key,value);
356 if (value !== h[key]) {
361 case DATE : // intentional fallthrough. Pre-replacer Dates are
362 // serialized in the toJSON stage. Dates here would
363 // have been produced by the replacer.
365 case STRING : return _string(value);
366 case NUMBER : return isFinite(value) ? value+EMPTY : NULL;
367 case BOOLEAN : return value+EMPTY;
368 case NULL : return NULL;
369 default : return undefined;
372 // Check for cyclical references in nested objects
373 for (i = stack.length - 1; i >= 0; --i) {
374 if (stack[i] === value) {
375 throw new Error("JSON.stringify. Cyclical reference");
379 arr = isArray(value);
381 // Add the object to the processing stack
385 for (i = value.length - 1; i >= 0; --i) {
386 a[i] = _serialize(value, i) || NULL;
389 // If whitelist provided, take only those keys
394 if (keys.hasOwnProperty(k)) {
395 v = _serialize(value, k);
397 a[i++] = _string(k) + colon + v;
403 // remove the array from the stack
406 if (space && a.length) {
408 OPEN_A + CR + _indent(a.join(COMMA_CR), space) + CR + CLOSE_A :
409 OPEN_O + CR + _indent(a.join(COMMA_CR), space) + CR + CLOSE_O;
412 OPEN_A + a.join(COMMA) + CLOSE_A :
413 OPEN_O + a.join(COMMA) + CLOSE_O;
418 return _serialize({'':o},'');
421 Y.mix(Y.namespace('JSON'),{
423 * Leverage native JSON stringify if the browser has a native
424 * implementation. In general, this is a good idea. See the Known Issues
425 * section in the JSON user guide for caveats. The default value is true
426 * for browsers with native JSON support.
428 * @property JSON.useNativeStringify
433 useNativeStringify : !!Native,
436 * Serializes a Date instance as a UTC date string. Used internally by
437 * stringify. Override this method if you need Dates serialized in a
440 * @method dateToString
441 * @param d {Date} The Date to serialize
442 * @return {String} stringified Date in UTC format YYYY-MM-DDTHH:mm:SSZ
445 dateToString : function (d) {
446 function _zeroPad(v) {
447 return v < 10 ? '0' + v : v;
450 return d.getUTCFullYear() + '-' +
451 _zeroPad(d.getUTCMonth() + 1) + '-' +
452 _zeroPad(d.getUTCDate()) + 'T' +
453 _zeroPad(d.getUTCHours()) + COLON +
454 _zeroPad(d.getUTCMinutes()) + COLON +
455 _zeroPad(d.getUTCSeconds()) + 'Z';
459 * <p>Converts an arbitrary value to a JSON string representation.</p>
461 * <p>Objects with cyclical references will trigger an exception.</p>
463 * <p>If a whitelist is provided, only matching object keys will be
464 * included. Alternately, a replacer function may be passed as the
465 * second parameter. This function is executed on every value in the
466 * input, and its return value will be used in place of the original value.
467 * This is useful to serialize specialized objects or class instances.</p>
469 * <p>If a positive integer or non-empty string is passed as the third
470 * parameter, the output will be formatted with carriage returns and
471 * indentation for readability. If a String is passed (such as "\t") it
472 * will be used once for each indentation level. If a number is passed,
473 * that number of spaces will be used.</p>
476 * @param o {MIXED} any arbitrary value to convert to JSON string
477 * @param w {Array|Function} (optional) whitelist of acceptable object
478 * keys to include, or a replacer function to modify the
479 * raw value before serialization
480 * @param ind {Number|String} (optional) indentation character or depth of
481 * spaces to format the output.
482 * @return {string} JSON string representation of the input
485 stringify : function (o,w,ind) {
486 return Native && Y.JSON.useNativeStringify ?
487 Native.stringify(o,w,ind) : _stringify(o,w,ind);
495 YUI.add('json', function(Y){}, '3.0.0' ,{use:['json-parse', 'json-stringify']});