1 /** 2 * @fileOverview Douglas Crockford’s JSON parser and serializer. 3 */ 4 5 /* 6 http://www.JSON.org/json2.js 7 2011-02-23 8 9 Public Domain. 10 11 NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK. 12 13 See http://www.JSON.org/js.html 14 15 16 This code should be minified before deployment. 17 See http://javascript.crockford.com/jsmin.html 18 19 USE YOUR OWN COPY. IT IS EXTREMELY UNWISE TO LOAD CODE FROM SERVERS YOU DO 20 NOT CONTROL. 21 22 23 This file creates a global JSON object containing two methods: stringify 24 and parse. 25 26 JSON.stringify(value, replacer, space) 27 value any JavaScript value, usually an object or array. 28 29 replacer an optional parameter that determines how object 30 values are stringified for objects. It can be a 31 function or an array of strings. 32 33 space an optional parameter that specifies the indentation 34 of nested structures. If it is omitted, the text will 35 be packed without extra whitespace. If it is a number, 36 it will specify the number of spaces to indent at each 37 level. If it is a string (such as '\t' or ' '), 38 it contains the characters used to indent at each level. 39 40 This method produces a JSON text from a JavaScript value. 41 42 When an object value is found, if the object contains a toJSON 43 method, its toJSON method will be called and the result will be 44 stringified. A toJSON method does not serialize: it returns the 45 value represented by the name/value pair that should be serialized, 46 or undefined if nothing should be serialized. The toJSON method 47 will be passed the key associated with the value, and this will be 48 bound to the value 49 50 For example, this would serialize Dates as ISO strings. 51 52 Date.prototype.toJSON = function (key) { 53 function f(n) { 54 // Format integers to have at least two digits. 55 return n < 10 ? '0' + n : n; 56 } 57 58 return this.getUTCFullYear() + '-' + 59 f(this.getUTCMonth() + 1) + '-' + 60 f(this.getUTCDate()) + 'T' + 61 f(this.getUTCHours()) + ':' + 62 f(this.getUTCMinutes()) + ':' + 63 f(this.getUTCSeconds()) + 'Z'; 64 }; 65 66 You can provide an optional replacer method. It will be passed the 67 key and value of each member, with this bound to the containing 68 object. The value that is returned from your method will be 69 serialized. If your method returns undefined, then the member will 70 be excluded from the serialization. 71 72 If the replacer parameter is an array of strings, then it will be 73 used to select the members to be serialized. It filters the results 74 such that only members with keys listed in the replacer array are 75 stringified. 76 77 Values that do not have JSON representations, such as undefined or 78 functions, will not be serialized. Such values in objects will be 79 dropped; in arrays they will be replaced with null. You can use 80 a replacer function to replace those with JSON values. 81 JSON.stringify(undefined) returns undefined. 82 83 The optional space parameter produces a stringification of the 84 value that is filled with line breaks and indentation to make it 85 easier to read. 86 87 If the space parameter is a non-empty string, then that string will 88 be used for indentation. If the space parameter is a number, then 89 the indentation will be that many spaces. 90 91 Example: 92 93 text = JSON.stringify(['e', {pluribus: 'unum'}]); 94 // text is '["e",{"pluribus":"unum"}]' 95 96 97 text = JSON.stringify(['e', {pluribus: 'unum'}], null, '\t'); 98 // text is '[\n\t"e",\n\t{\n\t\t"pluribus": "unum"\n\t}\n]' 99 100 text = JSON.stringify([new Date()], function (key, value) { 101 return this[key] instanceof Date ? 102 'Date(' + this[key] + ')' : value; 103 }); 104 // text is '["Date(---current time---)"]' 105 106 107 JSON.parse(text, reviver) 108 This method parses a JSON text to produce an object or array. 109 It can throw a SyntaxError exception. 110 111 The optional reviver parameter is a function that can filter and 112 transform the results. It receives each of the keys and values, 113 and its return value is used instead of the original value. 114 If it returns what it received, then the structure is not modified. 115 If it returns undefined then the member is deleted. 116 117 Example: 118 119 // Parse the text. Values that look like ISO date strings will 120 // be converted to Date objects. 121 122 myData = JSON.parse(text, function (key, value) { 123 var a; 124 if (typeof value === 'string') { 125 a = 126 /^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/.exec(value); 127 if (a) { 128 return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], 129 +a[5], +a[6])); 130 } 131 } 132 return value; 133 }); 134 135 myData = JSON.parse('["Date(09/09/2001)"]', function (key, value) { 136 var d; 137 if (typeof value === 'string' && 138 value.slice(0, 5) === 'Date(' && 139 value.slice(-1) === ')') { 140 d = new Date(value.slice(5, -1)); 141 if (d) { 142 return d; 143 } 144 } 145 return value; 146 }); 147 148 149 This is a reference implementation. You are free to copy, modify, or 150 redistribute. 151 */ 152 153 /*jslint evil: true, strict: false, regexp: false */ 154 155 /*members "", "\b", "\t", "\n", "\f", "\r", "\"", JSON, "\\", apply, 156 call, charCodeAt, getUTCDate, getUTCFullYear, getUTCHours, 157 getUTCMinutes, getUTCMonth, getUTCSeconds, hasOwnProperty, join, 158 lastIndex, length, parse, prototype, push, replace, slice, stringify, 159 test, toJSON, toString, valueOf 160 */ 161 162 163 // Create a JSON object only if one does not already exist. We create the 164 // methods in a closure to avoid creating global variables. 165 166 var JSON; 167 if (!JSON) { 168 JSON = {}; 169 } 170 171 (function () { 172 "use strict"; 173 174 function f(n) { 175 // Format integers to have at least two digits. 176 return n < 10 ? '0' + n : n; 177 } 178 179 if (typeof Date.prototype.toJSON !== 'function') { 180 181 Date.prototype.toJSON = function (key) { 182 183 return isFinite(this.valueOf()) ? 184 this.getUTCFullYear() + '-' + 185 f(this.getUTCMonth() + 1) + '-' + 186 f(this.getUTCDate()) + 'T' + 187 f(this.getUTCHours()) + ':' + 188 f(this.getUTCMinutes()) + ':' + 189 f(this.getUTCSeconds()) + 'Z' : null; 190 }; 191 192 String.prototype.toJSON = 193 Number.prototype.toJSON = 194 Boolean.prototype.toJSON = function (key) { 195 return this.valueOf(); 196 }; 197 } 198 199 var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g, 200 escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g, 201 gap, 202 indent, 203 meta = { // table of character substitutions 204 '\b': '\\b', 205 '\t': '\\t', 206 '\n': '\\n', 207 '\f': '\\f', 208 '\r': '\\r', 209 '"' : '\\"', 210 '\\': '\\\\' 211 }, 212 rep; 213 214 215 function quote(string) { 216 217 // If the string contains no control characters, no quote characters, and no 218 // backslash characters, then we can safely slap some quotes around it. 219 // Otherwise we must also replace the offending characters with safe escape 220 // sequences. 221 222 escapable.lastIndex = 0; 223 return escapable.test(string) ? '"' + string.replace(escapable, function (a) { 224 var c = meta[a]; 225 return typeof c === 'string' ? c : 226 '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4); 227 }) + '"' : '"' + string + '"'; 228 } 229 230 231 function str(key, holder) { 232 233 // Produce a string from holder[key]. 234 235 var i, // The loop counter. 236 k, // The member key. 237 v, // The member value. 238 length, 239 mind = gap, 240 partial, 241 value = holder[key]; 242 243 // If the value has a toJSON method, call it to obtain a replacement value. 244 245 if (value && typeof value === 'object' && 246 typeof value.toJSON === 'function') { 247 value = value.toJSON(key); 248 } 249 250 // If we were called with a replacer function, then call the replacer to 251 // obtain a replacement value. 252 253 if (typeof rep === 'function') { 254 value = rep.call(holder, key, value); 255 } 256 257 // What happens next depends on the value's type. 258 259 switch (typeof value) { 260 case 'string': 261 return quote(value); 262 263 case 'number': 264 265 // JSON numbers must be finite. Encode non-finite numbers as null. 266 267 return isFinite(value) ? String(value) : 'null'; 268 269 case 'boolean': 270 case 'null': 271 272 // If the value is a boolean or null, convert it to a string. Note: 273 // typeof null does not produce 'null'. The case is included here in 274 // the remote chance that this gets fixed someday. 275 276 return String(value); 277 278 // If the type is 'object', we might be dealing with an object or an array or 279 // null. 280 281 case 'object': 282 283 // Due to a specification blunder in ECMAScript, typeof null is 'object', 284 // so watch out for that case. 285 286 if (!value) { 287 return 'null'; 288 } 289 290 // Make an array to hold the partial results of stringifying this object value. 291 292 gap += indent; 293 partial = []; 294 295 // Is the value an array? 296 297 if (Object.prototype.toString.apply(value) === '[object Array]') { 298 299 // The value is an array. Stringify every element. Use null as a placeholder 300 // for non-JSON values. 301 302 length = value.length; 303 for (i = 0; i < length; i += 1) { 304 partial[i] = str(i, value) || 'null'; 305 } 306 307 // Join all of the elements together, separated with commas, and wrap them in 308 // brackets. 309 310 v = partial.length === 0 ? '[]' : gap ? 311 '[\n' + gap + partial.join(',\n' + gap) + '\n' + mind + ']' : 312 '[' + partial.join(',') + ']'; 313 gap = mind; 314 return v; 315 } 316 317 // If the replacer is an array, use it to select the members to be stringified. 318 319 if (rep && typeof rep === 'object') { 320 length = rep.length; 321 for (i = 0; i < length; i += 1) { 322 if (typeof rep[i] === 'string') { 323 k = rep[i]; 324 v = str(k, value); 325 if (v) { 326 partial.push(quote(k) + (gap ? ': ' : ':') + v); 327 } 328 } 329 } 330 } else { 331 332 // Otherwise, iterate through all of the keys in the object. 333 334 for (k in value) { 335 if (Object.prototype.hasOwnProperty.call(value, k)) { 336 v = str(k, value); 337 if (v) { 338 partial.push(quote(k) + (gap ? ': ' : ':') + v); 339 } 340 } 341 } 342 } 343 344 // Join all of the member texts together, separated with commas, 345 // and wrap them in braces. 346 347 v = partial.length === 0 ? '{}' : gap ? 348 '{\n' + gap + partial.join(',\n' + gap) + '\n' + mind + '}' : 349 '{' + partial.join(',') + '}'; 350 gap = mind; 351 return v; 352 } 353 } 354 355 // If the JSON object does not yet have a stringify method, give it one. 356 357 if (typeof JSON.stringify !== 'function') { 358 JSON.stringify = function (value, replacer, space) { 359 360 // The stringify method takes a value and an optional replacer, and an optional 361 // space parameter, and returns a JSON text. The replacer can be a function 362 // that can replace values, or an array of strings that will select the keys. 363 // A default replacer method can be provided. Use of the space parameter can 364 // produce text that is more easily readable. 365 366 var i; 367 gap = ''; 368 indent = ''; 369 370 // If the space parameter is a number, make an indent string containing that 371 // many spaces. 372 373 if (typeof space === 'number') { 374 for (i = 0; i < space; i += 1) { 375 indent += ' '; 376 } 377 378 // If the space parameter is a string, it will be used as the indent string. 379 380 } else if (typeof space === 'string') { 381 indent = space; 382 } 383 384 // If there is a replacer, it must be a function or an array. 385 // Otherwise, throw an error. 386 387 rep = replacer; 388 if (replacer && typeof replacer !== 'function' && 389 (typeof replacer !== 'object' || 390 typeof replacer.length !== 'number')) { 391 throw new Error('JSON.stringify'); 392 } 393 394 // Make a fake root object containing our value under the key of ''. 395 // Return the result of stringifying the value. 396 397 return str('', {'': value}); 398 }; 399 } 400 401 402 // If the JSON object does not yet have a parse method, give it one. 403 404 if (typeof JSON.parse !== 'function') { 405 JSON.parse = function (text, reviver) { 406 407 // The parse method takes a text and an optional reviver function, and returns 408 // a JavaScript value if the text is a valid JSON text. 409 410 var j; 411 412 function walk(holder, key) { 413 414 // The walk method is used to recursively walk the resulting structure so 415 // that modifications can be made. 416 417 var k, v, value = holder[key]; 418 if (value && typeof value === 'object') { 419 for (k in value) { 420 if (Object.prototype.hasOwnProperty.call(value, k)) { 421 v = walk(value, k); 422 if (v !== undefined) { 423 value[k] = v; 424 } else { 425 delete value[k]; 426 } 427 } 428 } 429 } 430 return reviver.call(holder, key, value); 431 } 432 433 434 // Parsing happens in four stages. In the first stage, we replace certain 435 // Unicode characters with escape sequences. JavaScript handles many characters 436 // incorrectly, either silently deleting them, or treating them as line endings. 437 438 text = String(text); 439 cx.lastIndex = 0; 440 if (cx.test(text)) { 441 text = text.replace(cx, function (a) { 442 return '\\u' + 443 ('0000' + a.charCodeAt(0).toString(16)).slice(-4); 444 }); 445 } 446 447 // In the second stage, we run the text against regular expressions that look 448 // for non-JSON patterns. We are especially concerned with '()' and 'new' 449 // because they can cause invocation, and '=' because it can cause mutation. 450 // But just to be safe, we want to reject all unexpected forms. 451 452 // We split the second stage into 4 regexp operations in order to work around 453 // crippling inefficiencies in IE's and Safari's regexp engines. First we 454 // replace the JSON backslash pairs with '@' (a non-JSON character). Second, we 455 // replace all simple value tokens with ']' characters. Third, we delete all 456 // open brackets that follow a colon or comma or that begin the text. Finally, 457 // we look to see that the remaining characters are only whitespace or ']' or 458 // ',' or ':' or '{' or '}'. If that is so, then the text is safe for eval. 459 460 if (/^[\],:{}\s]*$/ 461 .test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '@') 462 .replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']') 463 .replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) { 464 465 // In the third stage we use the eval function to compile the text into a 466 // JavaScript structure. The '{' operator is subject to a syntactic ambiguity 467 // in JavaScript: it can begin a block or an object literal. We wrap the text 468 // in parens to eliminate the ambiguity. 469 470 j = eval('(' + text + ')'); 471 472 // In the optional fourth stage, we recursively walk the new structure, passing 473 // each name/value pair to a reviver function for possible transformation. 474 475 return typeof reviver === 'function' ? 476 walk({'': j}, '') : j; 477 } 478 479 // If the text is not JSON parseable, then a SyntaxError is thrown. 480 481 throw new SyntaxError('JSON.parse'); 482 }; 483 } 484 }()); 485 486 487 // Do not enumerate the new JSON methods. 488 // (These lines are not included in the original code by Crockford.) 489 Object.prototype.dontEnum("toJSONString"); 490 Object.prototype.dontEnum("parseJSON"); 491 492 /** 493 * Create a JSONP-compatible response from the callback name and the desired data. 494 * @param {String} callback The name of the JSONP callback method 495 * @param {Object} data An arbitrary JavaScript object 496 */ 497 JSON.pad = function(data, callback) { 498 if (!callback) { 499 return; 500 } 501 return callback + "(" + JSON.stringify(data) + ")"; 502 } 503 504 /** 505 * Send a JSONP-compatible response if a the request contains callback data. 506 * This works out-of-the-box with jQuery but can be customized using the key argument. 507 * @param {Object} data An arbitrary JavaScript object 508 * @param {String} key The name of the property in req.data containing the JSONP callback method name 509 * @param {Boolean} resume Switch to define whether further processing should be continued or not 510 */ 511 JSON.sendPaddedResponse = function(data, key, resume) { 512 var callback = req.data[key || "callback"]; 513 if (callback) { 514 res.contentType = "text/javascript"; 515 res.write(JSON.pad(data, callback)); 516 resume || res.stop(); 517 } 518 return; 519 } 520