2 Copyright (c) 2010, Yahoo! Inc. All rights reserved.
3 Code licensed under the BSD License:
4 http://developer.yahoo.com/yui/license.html
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
47 function fromGlobal(ref) {
48 return (Y.config.win || this || {})[ref];
53 * Alias to native browser implementation of the JSON object if available.
59 var _JSON = fromGlobal('JSON'),
60 // Create an indirect reference to eval to allow for minification
61 _eval = fromGlobal('eval'),
62 Native = (Object.prototype.toString.call(_JSON) === '[object JSON]' && _JSON),
66 * Replace certain Unicode characters that JavaScript may handle incorrectly
67 * during eval--either by deleting them or treating them as line
68 * endings--with escape sequences.
69 * IMPORTANT NOTE: This regex will be used to modify the input if a match is
72 * @property _UNICODE_EXCEPTIONS
76 _UNICODE_EXCEPTIONS = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
80 * First step in the safety evaluation. Regex used to replace all escape
81 * sequences (i.e. "\\", etc) with '@' characters (a non-JSON character).
87 _ESCAPES = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,
90 * Second step in the safety evaluation. Regex used to replace all simple
91 * values with ']' characters.
97 _VALUES = /"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,
100 * Third step in the safety evaluation. Regex used to remove all open
101 * square brackets following a colon, comma, or at the beginning of the
104 * @property _BRACKETS
108 _BRACKETS = /(?:^|:|,)(?:\s*\[)+/g,
111 * Final step in the safety evaluation. Regex used to test the string left
112 * after all previous replacements for invalid characters.
118 _UNSAFE = /[^\],:{}\s]/,
121 * Replaces specific unicode characters with their appropriate \unnnn
122 * format. Some browsers ignore certain characters during eval.
124 * @method escapeException
125 * @param c {String} Unicode character
126 * @return {String} the \unnnn escapement of the character
129 _escapeException = function (c) {
130 return '\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
134 * Traverses nested objects, applying a reviver function to each (key,value)
135 * from the scope if the key:value's containing object. The value returned
136 * from the function will replace the original value in the key:value pair.
137 * If the value returned is undefined, the key will be omitted from the
141 * @param data {MIXED} Any JavaScript data
142 * @param reviver {Function} filter or mutation function
143 * @return {MIXED} The results of the filtered data
146 _revive = function (data, reviver) {
147 var walk = function (o,key) {
148 var k,v,value = o[key];
149 if (value && typeof value === 'object') {
151 if (value.hasOwnProperty(k)) {
153 if (v === undefined) {
161 return reviver.call(o,key,value);
164 return typeof reviver === 'function' ? walk({'':data},'') : data;
168 * Parse a JSON string, returning the native JavaScript representation.
170 * @param s {string} JSON string data
171 * @param reviver {function} (optional) function(k,v) passed each key value
172 * pair of object literals, allowing pruning or altering values
173 * @return {MIXED} the native JavaScript representation of the JSON string
174 * @throws SyntaxError
178 // JavaScript implementation in lieu of native browser support. Based on
179 // the json2.js library from http://json.org
180 _parse = function (s,reviver) {
181 // Replace certain Unicode characters that are otherwise handled
182 // incorrectly by some browser implementations.
183 // NOTE: This modifies the input if such characters are found!
184 s = s.replace(_UNICODE_EXCEPTIONS, _escapeException);
186 // Test for any remaining invalid characters
187 if (!_UNSAFE.test(s.replace(_ESCAPES,'@').
188 replace(_VALUES,']').
189 replace(_BRACKETS,''))) {
191 // Eval the text into a JavaScript data structure, apply any
192 // reviver function, and return
193 return _revive( _eval('(' + s + ')'), reviver );
196 throw new SyntaxError('JSON.parse');
199 Y.namespace('JSON').parse = function (s,reviver) {
200 if (typeof s !== 'string') {
204 return Native && Y.JSON.useNativeParse ?
205 Native.parse(s,reviver) : _parse(s,reviver);
208 function workingNative( k, v ) {
209 return k === "ok" ? true : v;
212 // Double check basic functionality. This is mainly to catch early broken
213 // implementations of the JSON API in Firefox 3.1 beta1 and beta2
216 useNative = ( Native.parse( '{"ok":false}', workingNative ) ).ok;
224 * Leverage native JSON parse if the browser has a native implementation.
225 * In general, this is a good idea. See the Known Issues section in the
226 * JSON user guide for caveats. The default value is true for browsers with
227 * native JSON support.
229 * @property useNativeParse
234 Y.JSON.useNativeParse = useNative;
238 YUI.add('json-stringify', function(Y) {
241 * Provides Y.JSON.stringify method for converting objects to JSON strings.
244 * @submodule json-stringify
248 var _JSON = (Y.config.win || {}).JSON,
250 isFunction= Lang.isFunction,
251 isObject = Lang.isObject,
252 isArray = Lang.isArray,
253 _toStr = Object.prototype.toString,
254 Native = (_toStr.call(_JSON) === '[object JSON]' && _JSON),
255 useNative = !!Native,
256 UNDEFINED = 'undefined',
264 'undefined' : UNDEFINED,
266 '[object String]' : STRING,
268 '[object Number]' : NUMBER,
270 '[object Boolean]' : BOOLEAN,
271 '[object Date]' : DATE,
272 '[object RegExp]' : OBJECT
286 // Regex used to capture characters that need escaping before enclosing
287 // their containing string in quotes.
288 _SPECIAL_CHARS = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
290 // Character substitution map for common escapes and special characters.
302 // Utility function used to determine how to serialize a variable.
305 return _allowable[t] || // number, string, boolean, undefined
306 _allowable[_toStr.call(o)] || // Number, String, Boolean, Date
308 (o ? OBJECT : NULL) : // object, array, null, misc natives
309 UNDEFINED); // function, unknown
312 // Escapes a special character to a safe Unicode representation
315 _CHARS[c] = '\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
320 // Enclose escaped strings in quotes
321 function _string(s) {
322 return QUOTE + s.replace(_SPECIAL_CHARS, _char) + QUOTE;
325 // Adds the provided space to the beginning of every line in the input string
326 function _indent(s,space) {
327 return s.replace(/^/gm, space);
330 // JavaScript implementation of stringify (see API declaration of stringify)
331 function _stringify(o,w,space) {
332 if (o === undefined) {
336 var replacer = isFunction(w) ? w : null,
337 format = _toStr.call(space).match(/String|Number/) || [],
338 _date = Y.JSON.dateToString,
342 if (replacer || !isArray(w)) {
346 // Ensure whitelist keys are unique (bug 2110391)
349 for (i = 0, len = w.length; i < len; ++i) {
355 // Per the spec, strings are truncated to 10 characters and numbers
356 // are converted to that number of spaces (max 10)
357 space = format[0] === 'Number' ?
358 new Array(Math.min(Math.max(0,space),10)+1).join(" ") :
359 (space || EMPTY).slice(0,10);
361 function _serialize(h,key) {
365 colon = space ? COLON_SP : COLON,
368 // Per the ECMA 5 spec, toJSON is applied before the replacer is
369 // called. Also per the spec, Date.prototype.toJSON has been added, so
370 // Date instances should be serialized prior to exposure to the
371 // replacer. I disagree with this decision, but the spec is the spec.
372 if (isObject(value) && isFunction(value.toJSON)) {
373 value = value.toJSON(key);
374 } else if (t === DATE) {
375 value = _date(value);
378 if (isFunction(replacer)) {
379 value = replacer.call(h,key,value);
382 if (value !== h[key]) {
387 case DATE : // intentional fallthrough. Pre-replacer Dates are
388 // serialized in the toJSON stage. Dates here would
389 // have been produced by the replacer.
391 case STRING : return _string(value);
392 case NUMBER : return isFinite(value) ? value+EMPTY : NULL;
393 case BOOLEAN : return value+EMPTY;
394 case NULL : return NULL;
395 default : return undefined;
398 // Check for cyclical references in nested objects
399 for (i = stack.length - 1; i >= 0; --i) {
400 if (stack[i] === value) {
401 throw new Error("JSON.stringify. Cyclical reference");
405 arr = isArray(value);
407 // Add the object to the processing stack
411 for (i = value.length - 1; i >= 0; --i) {
412 a[i] = _serialize(value, i) || NULL;
415 // If whitelist provided, take only those keys
420 if (keys.hasOwnProperty(k)) {
421 v = _serialize(value, k);
423 a[i++] = _string(k) + colon + v;
429 // remove the array from the stack
432 if (space && a.length) {
434 OPEN_A + CR + _indent(a.join(COMMA_CR), space) + CR + CLOSE_A :
435 OPEN_O + CR + _indent(a.join(COMMA_CR), space) + CR + CLOSE_O;
438 OPEN_A + a.join(COMMA) + CLOSE_A :
439 OPEN_O + a.join(COMMA) + CLOSE_O;
444 return _serialize({'':o},'');
447 // Double check basic native functionality. This is primarily to catch broken
448 // early JSON API implementations in Firefox 3.1 beta1 and beta2.
451 useNative = ( '0' === Native.stringify(0) );
457 Y.mix(Y.namespace('JSON'),{
459 * Leverage native JSON stringify if the browser has a native
460 * implementation. In general, this is a good idea. See the Known Issues
461 * section in the JSON user guide for caveats. The default value is true
462 * for browsers with native JSON support.
464 * @property JSON.useNativeStringify
469 useNativeStringify : useNative,
472 * Serializes a Date instance as a UTC date string. Used internally by
473 * stringify. Override this method if you need Dates serialized in a
476 * @method dateToString
477 * @param d {Date} The Date to serialize
478 * @return {String} stringified Date in UTC format YYYY-MM-DDTHH:mm:SSZ
479 * @deprecated Use a replacer function
482 dateToString : function (d) {
483 function _zeroPad(v) {
484 return v < 10 ? '0' + v : v;
487 return d.getUTCFullYear() + '-' +
488 _zeroPad(d.getUTCMonth() + 1) + '-' +
489 _zeroPad(d.getUTCDate()) + 'T' +
490 _zeroPad(d.getUTCHours()) + COLON +
491 _zeroPad(d.getUTCMinutes()) + COLON +
492 _zeroPad(d.getUTCSeconds()) + 'Z';
496 * <p>Converts an arbitrary value to a JSON string representation.</p>
498 * <p>Objects with cyclical references will trigger an exception.</p>
500 * <p>If a whitelist is provided, only matching object keys will be
501 * included. Alternately, a replacer function may be passed as the
502 * second parameter. This function is executed on every value in the
503 * input, and its return value will be used in place of the original value.
504 * This is useful to serialize specialized objects or class instances.</p>
506 * <p>If a positive integer or non-empty string is passed as the third
507 * parameter, the output will be formatted with carriage returns and
508 * indentation for readability. If a String is passed (such as "\t") it
509 * will be used once for each indentation level. If a number is passed,
510 * that number of spaces will be used.</p>
513 * @param o {MIXED} any arbitrary value to convert to JSON string
514 * @param w {Array|Function} (optional) whitelist of acceptable object
515 * keys to include, or a replacer function to modify the
516 * raw value before serialization
517 * @param ind {Number|String} (optional) indentation character or depth of
518 * spaces to format the output.
519 * @return {string} JSON string representation of the input
522 stringify : function (o,w,ind) {
523 return Native && Y.JSON.useNativeStringify ?
524 Native.stringify(o,w,ind) : _stringify(o,w,ind);
532 YUI.add('json', function(Y){}, '3.3.0' ,{use:['json-parse', 'json-stringify']});