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json.js
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| 1 | +/* | |
| 2 | + json.js | |
| 3 | + 2007-10-10 | |
| 4 | + | |
| 5 | + Public Domain | |
| 6 | + | |
| 7 | + This file adds these methods to JavaScript: | |
| 8 | + | |
| 9 | + array.toJSONString(whitelist) | |
| 10 | + boolean.toJSONString() | |
| 11 | + date.toJSONString() | |
| 12 | + number.toJSONString() | |
| 13 | + object.toJSONString(whitelist) | |
| 14 | + string.toJSONString() | |
| 15 | + These methods produce a JSON text from a JavaScript value. | |
| 16 | + It must not contain any cyclical references. Illegal values | |
| 17 | + will be excluded. | |
| 18 | + | |
| 19 | + The default conversion for dates is to an ISO string. You can | |
| 20 | + add a toJSONString method to any date object to get a different | |
| 21 | + representation. | |
| 22 | + | |
| 23 | + The object and array methods can take an optional whitelist | |
| 24 | + argument. A whitelist is an array of strings. If it is provided, | |
| 25 | + keys in objects not found in the whitelist are excluded. | |
| 26 | + | |
| 27 | + string.parseJSON(filter) | |
| 28 | + This method parses a JSON text to produce an object or | |
| 29 | + array. It can throw a SyntaxError exception. | |
| 30 | + | |
| 31 | + The optional filter parameter is a function which can filter and | |
| 32 | + transform the results. It receives each of the keys and values, and | |
| 33 | + its return value is used instead of the original value. If it | |
| 34 | + returns what it received, then structure is not modified. If it | |
| 35 | + returns undefined then the member is deleted. | |
| 36 | + | |
| 37 | + Example: | |
| 38 | + | |
| 39 | + // Parse the text. If a key contains the string 'date' then | |
| 40 | + // convert the value to a date. | |
| 41 | + | |
| 42 | + myData = text.parseJSON(function (key, value) { | |
| 43 | + return key.indexOf('date') >= 0 ? new Date(value) : value; | |
| 44 | + }); | |
| 45 | + | |
| 46 | + It is expected that these methods will formally become part of the | |
| 47 | + JavaScript Programming Language in the Fourth Edition of the | |
| 48 | + ECMAScript standard in 2008. | |
| 49 | + | |
| 50 | + This file will break programs with improper for..in loops. See | |
| 51 | + http://yuiblog.com/blog/2006/09/26/for-in-intrigue/ | |
| 52 | + | |
| 53 | + This is a reference implementation. You are free to copy, modify, or | |
| 54 | + redistribute. | |
| 55 | + | |
| 56 | + Use your own copy. It is extremely unwise to load untrusted third party | |
| 57 | + code into your pages. | |
| 58 | +*/ | |
| 59 | + | |
| 60 | +/*jslint evil: true */ | |
| 61 | + | |
| 62 | +// Augment the basic prototypes if they have not already been augmented. | |
| 63 | + | |
| 64 | +if (!Object.prototype.toJSONString) { | |
| 65 | + | |
| 66 | + Array.prototype.toJSONString = function (w) { | |
| 67 | + var a = [], // The array holding the partial texts. | |
| 68 | + i, // Loop counter. | |
| 69 | + l = this.length, | |
| 70 | + v; // The value to be stringified. | |
| 71 | + | |
| 72 | +// For each value in this array... | |
| 73 | + | |
| 74 | + for (i = 0; i < l; i += 1) { | |
| 75 | + v = this[i]; | |
| 76 | + switch (typeof v) { | |
| 77 | + case 'object': | |
| 78 | + | |
| 79 | +// Serialize a JavaScript object value. Treat objects thats lack the | |
| 80 | +// toJSONString method as null. Due to a specification error in ECMAScript, | |
| 81 | +// typeof null is 'object', so watch out for that case. | |
| 82 | + | |
| 83 | + if (v && typeof v.toJSONString === 'function') { | |
| 84 | + a.push(v.toJSONString(w)); | |
| 85 | + } else { | |
| 86 | + a.push('null'); | |
| 87 | + } | |
| 88 | + break; | |
| 89 | + | |
| 90 | + case 'string': | |
| 91 | + case 'number': | |
| 92 | + case 'boolean': | |
| 93 | + a.push(v.toJSONString()); | |
| 94 | + break; | |
| 95 | + default: | |
| 96 | + a.push('null'); | |
| 97 | + } | |
| 98 | + } | |
| 99 | + | |
| 100 | +// Join all of the member texts together and wrap them in brackets. | |
| 101 | + | |
| 102 | + return '[' + a.join(',') + ']'; | |
| 103 | + }; | |
| 104 | + | |
| 105 | + | |
| 106 | + Boolean.prototype.toJSONString = function () { | |
| 107 | + return String(this); | |
| 108 | + }; | |
| 109 | + | |
| 110 | + | |
| 111 | + Date.prototype.toJSONString = function () { | |
| 112 | + | |
| 113 | +// Eventually, this method will be based on the date.toISOString method. | |
| 114 | + | |
| 115 | + function f(n) { | |
| 116 | + | |
| 117 | +// Format integers to have at least two digits. | |
| 118 | + | |
| 119 | + return n < 10 ? '0' + n : n; | |
| 120 | + } | |
| 121 | + | |
| 122 | + return '"' + this.getUTCFullYear() + '-' + | |
| 123 | + f(this.getUTCMonth() + 1) + '-' + | |
| 124 | + f(this.getUTCDate()) + 'T' + | |
| 125 | + f(this.getUTCHours()) + ':' + | |
| 126 | + f(this.getUTCMinutes()) + ':' + | |
| 127 | + f(this.getUTCSeconds()) + 'Z"'; | |
| 128 | + }; | |
| 129 | + | |
| 130 | + | |
| 131 | + Number.prototype.toJSONString = function () { | |
| 132 | + | |
| 133 | +// JSON numbers must be finite. Encode non-finite numbers as null. | |
| 134 | + | |
| 135 | + return isFinite(this) ? String(this) : 'null'; | |
| 136 | + }; | |
| 137 | + | |
| 138 | + | |
| 139 | + Object.prototype.toJSONString = function (w) { | |
| 140 | + var a = [], // The array holding the partial texts. | |
| 141 | + k, // The current key. | |
| 142 | + i, // The loop counter. | |
| 143 | + v; // The current value. | |
| 144 | + | |
| 145 | +// If a whitelist (array of keys) is provided, use it assemble the components | |
| 146 | +// of the object. | |
| 147 | + | |
| 148 | + if (w) { | |
| 149 | + for (i = 0; i < w.length; i += 1) { | |
| 150 | + k = w[i]; | |
| 151 | + if (typeof k === 'string') { | |
| 152 | + v = this[k]; | |
| 153 | + switch (typeof v) { | |
| 154 | + case 'object': | |
| 155 | + | |
| 156 | +// Serialize a JavaScript object value. Ignore objects that lack the | |
| 157 | +// toJSONString method. Due to a specification error in ECMAScript, | |
| 158 | +// typeof null is 'object', so watch out for that case. | |
| 159 | + | |
| 160 | + if (v) { | |
| 161 | + if (typeof v.toJSONString === 'function') { | |
| 162 | + a.push(k.toJSONString() + ':' + | |
| 163 | + v.toJSONString(w)); | |
| 164 | + } | |
| 165 | + } else { | |
| 166 | + a.push(k.toJSONString() + ':null'); | |
| 167 | + } | |
| 168 | + break; | |
| 169 | + | |
| 170 | + case 'string': | |
| 171 | + case 'number': | |
| 172 | + case 'boolean': | |
| 173 | + a.push(k.toJSONString() + ':' + v.toJSONString()); | |
| 174 | + | |
| 175 | +// Values without a JSON representation are ignored. | |
| 176 | + | |
| 177 | + } | |
| 178 | + } | |
| 179 | + } | |
| 180 | + } else { | |
| 181 | + | |
| 182 | +// Iterate through all of the keys in the object, ignoring the proto chain | |
| 183 | +// and keys that are not strings. | |
| 184 | + | |
| 185 | + for (k in this) { | |
| 186 | + if (typeof k === 'string' && | |
| 187 | + Object.prototype.hasOwnProperty.apply(this, [k])) { | |
| 188 | + v = this[k]; | |
| 189 | + switch (typeof v) { | |
| 190 | + case 'object': | |
| 191 | + | |
| 192 | +// Serialize a JavaScript object value. Ignore objects that lack the | |
| 193 | +// toJSONString method. Due to a specification error in ECMAScript, | |
| 194 | +// typeof null is 'object', so watch out for that case. | |
| 195 | + | |
| 196 | + if (v) { | |
| 197 | + if (typeof v.toJSONString === 'function') { | |
| 198 | + a.push(k.toJSONString() + ':' + | |
| 199 | + v.toJSONString()); | |
| 200 | + } | |
| 201 | + } else { | |
| 202 | + a.push(k.toJSONString() + ':null'); | |
| 203 | + } | |
| 204 | + break; | |
| 205 | + | |
| 206 | + case 'string': | |
| 207 | + case 'number': | |
| 208 | + case 'boolean': | |
| 209 | + a.push(k.toJSONString() + ':' + v.toJSONString()); | |
| 210 | + | |
| 211 | +// Values without a JSON representation are ignored. | |
| 212 | + | |
| 213 | + } | |
| 214 | + } | |
| 215 | + } | |
| 216 | + } | |
| 217 | + | |
| 218 | +// Join all of the member texts together and wrap them in braces. | |
| 219 | + | |
| 220 | + return '{' + a.join(',') + '}'; | |
| 221 | + }; | |
| 222 | + | |
| 223 | + | |
| 224 | + (function (s) { | |
| 225 | + | |
| 226 | +// Augment String.prototype. We do this in an immediate anonymous function to | |
| 227 | +// avoid defining global variables. | |
| 228 | + | |
| 229 | +// m is a table of character substitutions. | |
| 230 | + | |
| 231 | + var m = { | |
| 232 | + '\b': '\\b', | |
| 233 | + '\t': '\\t', | |
| 234 | + '\n': '\\n', | |
| 235 | + '\f': '\\f', | |
| 236 | + '\r': '\\r', | |
| 237 | + '"' : '\\"', | |
| 238 | + '\\': '\\\\' | |
| 239 | + }; | |
| 240 | + | |
| 241 | + | |
| 242 | + s.parseJSON = function (filter) { | |
| 243 | + var j; | |
| 244 | + | |
| 245 | + function walk(k, v) { | |
| 246 | + var i, n; | |
| 247 | + if (v && typeof v === 'object') { | |
| 248 | + for (i in v) { | |
| 249 | + if (Object.prototype.hasOwnProperty.apply(v, [i])) { | |
| 250 | + n = walk(i, v[i]); | |
| 251 | + if (n !== undefined) { | |
| 252 | + v[i] = n; | |
| 253 | + } | |
| 254 | + } | |
| 255 | + } | |
| 256 | + } | |
| 257 | + return filter(k, v); | |
| 258 | + } | |
| 259 | + | |
| 260 | + | |
| 261 | +// Parsing happens in three stages. In the first stage, we run the text against | |
| 262 | +// a regular expression which looks for non-JSON characters. We are especially | |
| 263 | +// concerned with '()' and 'new' because they can cause invocation, and '=' | |
| 264 | +// because it can cause mutation. But just to be safe, we will reject all | |
| 265 | +// unexpected characters. | |
| 266 | + | |
| 267 | +// We split the first stage into 4 regexp operations in order to work around | |
| 268 | +// crippling deficiencies in IE's and Safari's regexp engines. First we replace | |
| 269 | +// all backslash pairs with '@' (a non-JSON character). Second, we replace all | |
| 270 | +// simple value tokens with ']' characters. Third, we delete all open brackets | |
| 271 | +// that follow a colon or comma or that begin the text. Finally, we look to see | |
| 272 | +// that the remaining characters are only whitespace or ']' or ',' or ':' or '{' | |
| 273 | +// or '}'. If that is so, then the text is safe for eval. | |
| 274 | + | |
| 275 | + if (/^[\],:{}\s]*$/.test(this.replace(/\\./g, '@'). | |
| 276 | + replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(:?[eE][+\-]?\d+)?/g, ']'). | |
| 277 | + replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) { | |
| 278 | + | |
| 279 | +// In the second stage we use the eval function to compile the text into a | |
| 280 | +// JavaScript structure. The '{' operator is subject to a syntactic ambiguity | |
| 281 | +// in JavaScript: it can begin a block or an object literal. We wrap the text | |
| 282 | +// in parens to eliminate the ambiguity. | |
| 283 | + | |
| 284 | + j = eval('(' + this + ')'); | |
| 285 | + | |
| 286 | +// In the optional third stage, we recursively walk the new structure, passing | |
| 287 | +// each name/value pair to a filter function for possible transformation. | |
| 288 | + | |
| 289 | + return typeof filter === 'function' ? walk('', j) : j; | |
| 290 | + } | |
| 291 | + | |
| 292 | +// If the text is not JSON parseable, then a SyntaxError is thrown. | |
| 293 | + | |
| 294 | + throw new SyntaxError('parseJSON'); | |
| 295 | + }; | |
| 296 | + | |
| 297 | + | |
| 298 | + s.toJSONString = function () { | |
| 299 | + | |
| 300 | +// If the string contains no control characters, no quote characters, and no | |
| 301 | +// backslash characters, then we can simply slap some quotes around it. | |
| 302 | +// Otherwise we must also replace the offending characters with safe | |
| 303 | +// sequences. | |
| 304 | + | |
| 305 | + if (/["\\\x00-\x1f]/.test(this)) { | |
| 306 | + return '"' + this.replace(/[\x00-\x1f\\"]/g, function (a) { | |
| 307 | + var c = m[a]; | |
| 308 | + if (c) { | |
| 309 | + return c; | |
| 310 | + } | |
| 311 | + c = a.charCodeAt(); | |
| 312 | + return '\\u00' + Math.floor(c / 16).toString(16) + | |
| 313 | + (c % 16).toString(16); | |
| 314 | + }) + '"'; | |
| 315 | + } | |
| 316 | + return '"' + this + '"'; | |
| 317 | + }; | |
| 318 | + })(String.prototype); | |
| 319 | +} | |
| \ No newline at end of file | ... | ... |
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