json2-es5-compat.js revision cfb0617749a64f2e177386b030d46007b8c4b179
1/* 2 http://www.JSON.org/json2.js 3 2009-04-16 4 5 Public Domain. 6 7 NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK. 8 9 See http://www.JSON.org/js.html 10 11 This file creates a global JSON object containing two methods: stringify 12 and parse. 13 14 JSON.stringify(value, replacer, space) 15 value any JavaScript value, usually an object or array. 16 17 replacer an optional parameter that determines how object 18 values are stringified for objects. It can be a 19 function or an array of strings. 20 21 space an optional parameter that specifies the indentation 22 of nested structures. If it is omitted, the text will 23 be packed without extra whitespace. If it is a number, 24 it will specify the number of spaces to indent at each 25 level. If it is a string (such as '\t' or ' '), 26 it contains the characters used to indent at each level. 27 28 This method produces a JSON text from a JavaScript value. 29 30 When an object value is found, if the object contains a toJSON 31 method, its toJSON method will be called and the result will be 32 stringified. A toJSON method does not serialize: it returns the 33 value represented by the name/value pair that should be serialized, 34 or undefined if nothing should be serialized. The toJSON method 35 will be passed the key associated with the value, and this will be 36 bound to the object holding the key. 37 38 For example, this would serialize Dates as ISO strings. 39 40 Date.prototype.toJSON = function (key) { 41 function f(n) { 42 // Format integers to have at least two digits. 43 return n < 10 ? '0' + n : n; 44 } 45 46 return this.getUTCFullYear() + '-' + 47 f(this.getUTCMonth() + 1) + '-' + 48 f(this.getUTCDate()) + 'T' + 49 f(this.getUTCHours()) + ':' + 50 f(this.getUTCMinutes()) + ':' + 51 f(this.getUTCSeconds()) + 'Z'; 52 }; 53 54 You can provide an optional replacer method. It will be passed the 55 key and value of each member, with this bound to the containing 56 object. The value that is returned from your method will be 57 serialized. If your method returns undefined, then the member will 58 be excluded from the serialization. 59 60 If the replacer parameter is an array of strings, then it will be 61 used to select the members to be serialized. It filters the results 62 such that only members with keys listed in the replacer array are 63 stringified. 64 65 Values that do not have JSON representations, such as undefined or 66 functions, will not be serialized. Such values in objects will be 67 dropped; in arrays they will be replaced with null. You can use 68 a replacer function to replace those with JSON values. 69 JSON.stringify(undefined) returns undefined. 70 71 The optional space parameter produces a stringification of the 72 value that is filled with line breaks and indentation to make it 73 easier to read. 74 75 If the space parameter is a non-empty string, then that string will 76 be used for indentation. If the space parameter is a number, then 77 the indentation will be that many spaces. 78 79 Example: 80 81 text = JSON.stringify(['e', {pluribus: 'unum'}]); 82 // text is '["e",{"pluribus":"unum"}]' 83 84 85 text = JSON.stringify(['e', {pluribus: 'unum'}], null, '\t'); 86 // text is '[\n\t"e",\n\t{\n\t\t"pluribus": "unum"\n\t}\n]' 87 88 text = JSON.stringify([new Date()], function (key, value) { 89 return this[key] instanceof Date ? 90 'Date(' + this[key] + ')' : value; 91 }); 92 // text is '["Date(---current time---)"]' 93 94 95 JSON.parse(text, reviver) 96 This method parses a JSON text to produce an object or array. 97 It can throw a SyntaxError exception. 98 99 The optional reviver parameter is a function that can filter and 100 transform the results. It receives each of the keys and values, 101 and its return value is used instead of the original value. 102 If it returns what it received, then the structure is not modified. 103 If it returns undefined then the member is deleted. 104 105 Example: 106 107 // Parse the text. Values that look like ISO date strings will 108 // be converted to Date objects. 109 110 myData = JSON.parse(text, function (key, value) { 111 var a; 112 if (typeof value === 'string') { 113 a = 114/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/.exec(value); 115 if (a) { 116 return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], 117 +a[5], +a[6])); 118 } 119 } 120 return value; 121 }); 122 123 myData = JSON.parse('["Date(09/09/2001)"]', function (key, value) { 124 var d; 125 if (typeof value === 'string' && 126 value.slice(0, 5) === 'Date(' && 127 value.slice(-1) === ')') { 128 d = new Date(value.slice(5, -1)); 129 if (d) { 130 return d; 131 } 132 } 133 return value; 134 }); 135 136 137 This is a reference implementation. You are free to copy, modify, or 138 redistribute. 139 140 This code should be minified before deployment. 141 See http://javascript.crockford.com/jsmin.html 142 143 USE YOUR OWN COPY. IT IS EXTREMELY UNWISE TO LOAD CODE FROM SERVERS YOU DO 144 NOT CONTROL. 145*/ 146 147/*jslint evil: true */ 148 149/*global JSON */ 150 151/*members "", "\b", "\t", "\n", "\f", "\r", "\"", JSON, "\\", apply, 152 call, charCodeAt, getUTCDate, getUTCFullYear, getUTCHours, 153 getUTCMinutes, getUTCMonth, getUTCSeconds, hasOwnProperty, join, 154 lastIndex, length, parse, prototype, push, replace, slice, stringify, 155 test, toJSON, toString, valueOf 156*/ 157 158// Create a JSON object only if one does not already exist. We create the 159// methods in a closure to avoid creating global variables. 160 161if (!this.JSON) { 162 JSON = {}; 163} 164(function () { 165 166 function f(n) { 167 // Format integers to have at least two digits. 168 return n < 10 ? '0' + n : n; 169 } 170 171 if (typeof Date.prototype.toJSON !== 'function') { 172 173 Date.prototype.toJSON = function (key) { 174 175 return this.getUTCFullYear() + '-' + 176 f(this.getUTCMonth() + 1) + '-' + 177 f(this.getUTCDate()) + 'T' + 178 f(this.getUTCHours()) + ':' + 179 f(this.getUTCMinutes()) + ':' + 180 f(this.getUTCSeconds()) + 'Z'; 181 }; 182 } 183 184 var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g, 185 escapable = /[\\\"\x00-\x1f]/g, 186 gap, 187 indent, 188 meta = { // table of character substitutions 189 '\b': '\\b', 190 '\t': '\\t', 191 '\n': '\\n', 192 '\f': '\\f', 193 '\r': '\\r', 194 '"' : '\\"', 195 '\\': '\\\\' 196 }, 197 rep; 198 199 200 function quote(string) { 201 202// If the string contains no control characters, no quote characters, and no 203// backslash characters, then we can safely slap some quotes around it. 204// Otherwise we must also replace the offending characters with safe escape 205// sequences. 206 207 escapable.lastIndex = 0; 208 return escapable.test(string) ? 209 '"' + string.replace(escapable, function (a) { 210 var c = meta[a]; 211 return typeof c === 'string' ? c : 212 '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4); 213 }) + '"' : 214 '"' + string + '"'; 215 } 216 217 218 function str(key, holder) { 219 220// Produce a string from holder[key]. 221 222 var i, // The loop counter. 223 k, // The member key. 224 v, // The member value. 225 length, 226 mind = gap, 227 partial, 228 value = holder[key]; 229 230// If the value has a toJSON method, call it to obtain a replacement value. 231 232 if (value && typeof value === 'object' && 233 typeof value.toJSON === 'function') { 234 value = value.toJSON(key); 235 } 236 237// If we were called with a replacer function, then call the replacer to 238// obtain a replacement value. 239 240 if (typeof rep === 'function') { 241 value = rep.call(holder, key, value); 242 } 243 244// What happens next depends on the value's type. 245 246 if (value && ((typeof value) === "object")) { 247 if (value.constructor === String || value.constructor === Number || value.constructor === Boolean) 248 value = value.valueOf(); 249 } 250 251 switch (typeof value) { 252 case 'string': 253 return quote(value); 254 255 case 'number': 256 257// JSON numbers must be finite. Encode non-finite numbers as null. 258 259 return isFinite(value) ? String(value) : 'null'; 260 261 case 'boolean': 262 case 'null': 263 264// If the value is a boolean or null, convert it to a string. Note: 265// typeof null does not produce 'null'. The case is included here in 266// the remote chance that this gets fixed someday. 267 268 return String(value); 269 270// If the type is 'object', we might be dealing with an object or an array or 271// null. 272 273 case 'object': 274 275// Due to a specification blunder in ECMAScript, typeof null is 'object', 276// so watch out for that case. 277 278 if (!value) { 279 return 'null'; 280 } 281 282// Make an array to hold the partial results of stringifying this object value. 283 284 gap += indent; 285 partial = []; 286 287// Is the value an array? 288 289 if (Object.prototype.toString.apply(value) === '[object Array]') { 290 291// The value is an array. Stringify every element. Use null as a placeholder 292// for non-JSON values. 293 294 length = value.length; 295 for (i = 0; i < length; i += 1) { 296 partial[i] = str(i, value) || 'null'; 297 } 298 299// Join all of the elements together, separated with commas, and wrap them in 300// brackets. 301 302 v = partial.length === 0 ? '[]' : 303 gap ? '[\n' + gap + 304 partial.join(',\n' + gap) + '\n' + 305 mind + ']' : 306 '[' + partial.join(',') + ']'; 307 gap = mind; 308 return v; 309 } 310 311// If the replacer is an array, use it to select the members to be stringified. 312 313 if (rep && typeof rep === 'object') { 314 length = rep.length; 315 for (i = 0; i < length; i += 1) { 316 k = rep[i]; 317 if (typeof k === 'string') { 318 v = str(k, value); 319 if (v) { 320 partial.push(quote(k) + (gap ? ': ' : ':') + v); 321 } 322 } 323 } 324 } else { 325 326// Otherwise, iterate through all of the keys in the object. 327 328 for (k in value) { 329 if (Object.hasOwnProperty.call(value, k)) { 330 v = str(k, value); 331 if (v) { 332 partial.push(quote(k) + (gap ? ': ' : ':') + v); 333 } 334 } 335 } 336 } 337 338// Join all of the member texts together, separated with commas, 339// and wrap them in braces. 340 341 v = partial.length === 0 ? '{}' : 342 gap ? '{\n' + gap + partial.join(',\n' + gap) + '\n' + 343 mind + '}' : '{' + partial.join(',') + '}'; 344 gap = mind; 345 return v; 346 } 347 } 348 349// If the JSON object does not yet have a stringify method, give it one. 350 351 if (typeof JSON.stringify !== 'function') { 352 JSON.stringify = function (value, replacer, space) { 353 354// The stringify method takes a value and an optional replacer, and an optional 355// space parameter, and returns a JSON text. The replacer can be a function 356// that can replace values, or an array of strings that will select the keys. 357// A default replacer method can be provided. Use of the space parameter can 358// produce text that is more easily readable. 359 360 var i; 361 gap = ''; 362 indent = ''; 363 364// If the space parameter is a number, make an indent string containing that 365// many spaces. 366 367 if (typeof space === 'number') { 368 for (i = 0; i < space; i += 1) { 369 indent += ' '; 370 } 371 372// If the space parameter is a string, it will be used as the indent string. 373 374 } else if (typeof space === 'string') { 375 indent = space; 376 } 377 378// If there is a replacer, it must be a function or an array. 379// Otherwise, throw an error. 380 381 rep = replacer; 382 if (replacer && typeof replacer !== 'function' && 383 (typeof replacer !== 'object' || 384 typeof replacer.length !== 'number')) { 385 throw new Error('JSON.stringify'); 386 } 387 388// Make a fake root object containing our value under the key of ''. 389// Return the result of stringifying the value. 390 391 return str('', {'': value}); 392 }; 393 } 394 395 396// If the JSON object does not yet have a parse method, give it one. 397 398 if (typeof JSON.parse !== 'function') { 399 JSON.parse = function (text, reviver) { 400 401// The parse method takes a text and an optional reviver function, and returns 402// a JavaScript value if the text is a valid JSON text. 403 404 var j; 405 406 function walk(holder, key) { 407 408// The walk method is used to recursively walk the resulting structure so 409// that modifications can be made. 410 411 var k, v, value = holder[key]; 412 if (value && typeof value === 'object') { 413 for (k in value) { 414 if (Object.hasOwnProperty.call(value, k)) { 415 v = walk(value, k); 416 if (v !== undefined) { 417 value[k] = v; 418 } else { 419 delete value[k]; 420 } 421 } 422 } 423 } 424 return reviver.call(holder, key, value); 425 } 426 427 428// Parsing happens in four stages. In the first stage, we replace certain 429// Unicode characters with escape sequences. JavaScript handles many characters 430// incorrectly, either silently deleting them, or treating them as line endings. 431 432 cx.lastIndex = 0; 433 if (cx.test(text)) { 434 text = text.replace(cx, function (a) { 435 return '\\u' + 436 ('0000' + a.charCodeAt(0).toString(16)).slice(-4); 437 }); 438 } 439 440// In the second stage, we run the text against regular expressions that look 441// for non-JSON patterns. We are especially concerned with '()' and 'new' 442// because they can cause invocation, and '=' because it can cause mutation. 443// But just to be safe, we want to reject all unexpected forms. 444 445// We split the second stage into 4 regexp operations in order to work around 446// crippling inefficiencies in IE's and Safari's regexp engines. First we 447// replace the JSON backslash pairs with '@' (a non-JSON character). Second, we 448// replace all simple value tokens with ']' characters. Third, we delete all 449// open brackets that follow a colon or comma or that begin the text. Finally, 450// we look to see that the remaining characters are only whitespace or ']' or 451// ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval. 452 453 if (/^[\],:{}\s]*$/. 454test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '@'). 455replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']'). 456replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) { 457 458// In the third stage we use the eval function to compile the text into a 459// JavaScript structure. The '{' operator is subject to a syntactic ambiguity 460// in JavaScript: it can begin a block or an object literal. We wrap the text 461// in parens to eliminate the ambiguity. 462 463 j = eval('(' + text + ')'); 464 465// In the optional fourth stage, we recursively walk the new structure, passing 466// each name/value pair to a reviver function for possible transformation. 467 468 return typeof reviver === 'function' ? 469 walk({'': j}, '') : j; 470 } 471 472// If the text is not JSON parseable, then a SyntaxError is thrown. 473 474 throw new SyntaxError('JSON.parse'); 475 }; 476 } 477}()); 478