| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| goog.provide('cvox.ChromeVoxJSON'); |
| |
| |
| /** |
| * @fileoverview A simple wrapper around the JSON APIs. |
| * If it is possible to use the browser's built in native JSON, then |
| * cvox.ChromeVoxJSON is the same as JSON. |
| * If the page has its own version of JSON, cvox.ChromeVoxJSON will use its |
| * own implementation (rather than the version of JSON on the page |
| * which may be outdated/broken). |
| */ |
| |
| if (!cvox.ChromeVoxJSON) { |
| /** |
| * @type {Object} |
| */ |
| cvox.ChromeVoxJSON = {}; |
| } |
| |
| if (window.JSON && window.JSON.toString() == '[object JSON]') { |
| cvox.ChromeVoxJSON = window.JSON; |
| } else { |
| /* |
| * JSON implementation renamed to cvox.ChromeVoxJSON. |
| * This only gets called if the page has its own version of JSON. |
| * |
| * Based on: |
| * http://www.JSON.org/json2.js |
| * 2010-03-20 |
| * |
| * Public Domain. |
| * |
| * NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK. |
| * |
| * See http://www.JSON.org/js.html |
| */ |
| (function() { |
| function f(n) { |
| // Format integers to have at least two digits. |
| return n < 10 ? '0' + n : n; |
| } |
| |
| if (typeof Date.prototype.toJSON !== 'function') { |
| |
| Date.prototype.toJSON = function(key) { |
| |
| return isFinite(this.valueOf()) ? |
| this.getUTCFullYear() + '-' + |
| f(this.getUTCMonth() + 1) + '-' + |
| f(this.getUTCDate()) + 'T' + |
| f(this.getUTCHours()) + ':' + |
| f(this.getUTCMinutes()) + ':' + |
| f(this.getUTCSeconds()) + 'Z' : 'null'; |
| }; |
| |
| String.prototype.toJSON = |
| Number.prototype.toJSON = |
| Boolean.prototype.toJSON = function(key) { |
| return /** @type {string} */ (this.valueOf()); |
| }; |
| } |
| |
| var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g, |
| escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g, |
| gap, |
| indent, |
| meta = { // table of character substitutions |
| '\b': '\\b', |
| '\t': '\\t', |
| '\n': '\\n', |
| '\f': '\\f', |
| '\r': '\\r', |
| '"' : '\\"', |
| '\\': '\\\\' |
| }, |
| rep; |
| |
| |
| function quote(string) { |
| |
| // If the string contains no control characters, no quote characters, and |
| // no backslash characters, then we can safely slap some quotes around it. |
| // Otherwise we must also replace the offending characters with safe |
| // escape sequences. |
| |
| escapable.lastIndex = 0; |
| return escapable.test(string) ? |
| '"' + string.replace(escapable, function(a) { |
| var c = meta[a]; |
| return typeof c === 'string' ? c : |
| '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4); |
| }) + '"' : |
| '"' + string + '"'; |
| } |
| |
| |
| function str(key, holder) { |
| |
| // Produce a string from holder[key]. |
| |
| var i, // The loop counter. |
| k, // The member key. |
| v, // The member value. |
| length, |
| mind = gap, |
| partial, |
| value = holder[key]; |
| |
| // If the value has a toJSON method, call it to obtain a replacement |
| // value. |
| |
| if (value && typeof value === 'object' && |
| typeof value.toJSON === 'function') { |
| value = value.toJSON(key); |
| } |
| |
| // If we were called with a replacer function, then call the replacer to |
| // obtain a replacement value. |
| |
| if (typeof rep === 'function') { |
| value = rep.call(holder, key, value); |
| } |
| |
| // What happens next depends on the value's type. |
| |
| switch (typeof value) { |
| case 'string': |
| return quote(value); |
| |
| case 'number': |
| // JSON numbers must be finite. Encode non-finite numbers as null. |
| return isFinite(value) ? String(value) : 'null'; |
| |
| case 'boolean': |
| case 'null': |
| // If the value is a boolean or null, convert it to a string. Note: |
| // typeof null does not produce 'null'. The case is included here in |
| // the remote chance that this gets fixed someday. |
| return String(value); |
| |
| // If the type is 'object', we might be dealing with an object or an |
| // array or null. |
| |
| case 'object': |
| |
| // Due to a specification blunder in ECMAScript, typeof null is |
| // 'object', so watch out for that case. |
| |
| if (!value) { |
| return 'null'; |
| } |
| |
| // Make an array to hold the partial results of stringifying this |
| // object value. |
| |
| gap += indent; |
| partial = []; |
| |
| // Is the value an array? |
| |
| if (Object.prototype.toString.apply(value) === '[object Array]') { |
| |
| // The value is an array. Stringify every element. Use null as a |
| // placeholder for non-JSON values. |
| |
| length = value.length; |
| for (i = 0; i < length; i += 1) { |
| partial[i] = str(i, value) || 'null'; |
| } |
| |
| // Join all of the elements together, separated with commas, and |
| // wrap them in brackets. |
| |
| v = partial.length === 0 ? '[]' : |
| gap ? '[\n' + gap + |
| partial.join(',\n' + gap) + '\n' + |
| mind + ']' : |
| '[' + partial.join(',') + ']'; |
| gap = mind; |
| return v; |
| } |
| |
| // If the replacer is an array, use it to select the members to be |
| // stringified. |
| |
| if (rep && typeof rep === 'object') { |
| length = rep.length; |
| for (i = 0; i < length; i += 1) { |
| k = rep[i]; |
| if (typeof k === 'string') { |
| v = str(k, value); |
| if (v) { |
| partial.push(quote(k) + (gap ? ': ' : ':') + v); |
| } |
| } |
| } |
| } else { |
| |
| // Otherwise, iterate through all of the keys in the object. |
| for (k in value) { |
| if (Object.hasOwnProperty.call(value, k)) { |
| v = str(k, value); |
| if (v) { |
| partial.push(quote(k) + (gap ? ': ' : ':') + v); |
| } |
| } |
| } |
| } |
| |
| // Join all of the member texts together, separated with commas, |
| // and wrap them in braces. |
| |
| v = partial.length === 0 ? '{}' : |
| gap ? '{\n' + gap + partial.join(',\n' + gap) + '\n' + |
| mind + '}' : '{' + partial.join(',') + '}'; |
| gap = mind; |
| return v; |
| } |
| } |
| |
| // If the JSON object does not yet have a stringify method, give it one. |
| |
| if (typeof cvox.ChromeVoxJSON.stringify !== 'function') { |
| /** |
| * @param {*} value Input object. |
| * @param {(Array.<string>|(function(string, *) : *)|null)=} replacer |
| * Replacer array or function. |
| * @param {(number|string|null)=} space Whitespace character. |
| * @return {string} json string which represents jsonObj. |
| */ |
| cvox.ChromeVoxJSON.stringify = function(value, replacer, space) { |
| |
| // The stringify method takes a value and an optional replacer, and an |
| // optional space parameter, and returns a JSON text. The replacer can |
| // be a function that can replace values, or an array of strings that |
| // will select the keys. A default replacer method can be provided. Use |
| // of the space parameter can produce text that is more easily readable. |
| |
| var i; |
| gap = ''; |
| indent = ''; |
| |
| // If the space parameter is a number, make an indent string containing |
| // that many spaces. |
| |
| if (typeof space === 'number') { |
| for (i = 0; i < space; i += 1) { |
| indent += ' '; |
| } |
| |
| // If the space parameter is a string, it will be used as the indent |
| // string. |
| |
| } else if (typeof space === 'string') { |
| indent = space; |
| } |
| |
| // If there is a replacer, it must be a function or an array. |
| // Otherwise, throw an error. |
| |
| rep = replacer; |
| if (replacer && typeof replacer !== 'function' && |
| (typeof replacer !== 'object' || |
| typeof replacer.length !== 'number')) { |
| throw new Error('JSON.stringify'); |
| } |
| |
| // Make a fake root object containing our value under the key of ''. |
| // Return the result of stringifying the value. |
| |
| return str('', {'': value}); |
| }; |
| } |
| |
| |
| // If the JSON object does not yet have a parse method, give it one. |
| |
| if (typeof cvox.ChromeVoxJSON.parse !== 'function') { |
| /** |
| * @param {string} text The string to parse. |
| * @param {(function(string, *) : *|null)=} reviver Reviver function. |
| * @return {*} The JSON object. |
| */ |
| cvox.ChromeVoxJSON.parse = function(text, reviver) { |
| |
| // The parse method takes a text and an optional reviver function, and |
| // returns a JavaScript value if the text is a valid JSON text. |
| |
| var j; |
| |
| function walk(holder, key) { |
| |
| // The walk method is used to recursively walk the resulting structure |
| // so that modifications can be made. |
| |
| var k, v, value = holder[key]; |
| if (value && typeof value === 'object') { |
| for (k in value) { |
| if (Object.hasOwnProperty.call(value, k)) { |
| v = walk(value, k); |
| if (v !== undefined) { |
| value[k] = v; |
| } else { |
| delete value[k]; |
| } |
| } |
| } |
| } |
| return reviver.call(holder, key, value); |
| } |
| |
| |
| // Parsing happens in four stages. In the first stage, we replace |
| // certain Unicode characters with escape sequences. JavaScript handles |
| // many characters incorrectly, either silently deleting them, or |
| // treating them as line endings. |
| |
| text = String(text); |
| cx.lastIndex = 0; |
| if (cx.test(text)) { |
| text = text.replace(cx, function(a) { |
| return '\\u' + |
| ('0000' + a.charCodeAt(0).toString(16)).slice(-4); |
| }); |
| } |
| |
| // In the second stage, we run the text against regular expressions that |
| // look for non-JSON patterns. We are especially concerned with '()' and |
| // 'new' because they can cause invocation, and '=' because it can cause |
| // mutation. But just to be safe, we want to reject all unexpected |
| // forms. |
| // We split the second stage into 4 regexp operations in order to work |
| // around crippling inefficiencies in IE's and Safari's regexp engines. |
| // First we replace the JSON backslash pairs with '@' (a non-JSON |
| // character). Second, we replace all simple value tokens with ']' |
| // characters. Third, we delete all open brackets that follow a colon or |
| // comma or that begin the text. Finally, we look to see that the |
| // remaining characters are only whitespace or ']' or ',' or ':' or '{' |
| // or '}'. If that is so, then the text is safe for eval. |
| |
| if (/^[\],:{}\s]*$/. |
| test(text.replace(/\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g, '@'). |
| replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']'). |
| replace(/(?:^|:|,)(?:\s*\[)+/g, ''))) { |
| |
| // In the third stage we use the eval function to compile the text |
| // into a JavaScript structure. The '{' operator is subject to a |
| // syntactic ambiguity in JavaScript: it can begin a block or an |
| // object literal. We wrap the text in parens to eliminate the |
| // ambiguity. |
| |
| j = eval('(' + text + ')'); |
| |
| // In the optional fourth stage, we recursively walk the new |
| // structure, passing each name/value pair to a reviver function for |
| // possible transformation. |
| return typeof reviver === 'function' ? walk({'': j}, '') : j; |
| } |
| |
| // If the text is not JSON parseable, then a SyntaxError is thrown. |
| |
| throw new SyntaxError('JSON.parse'); |
| }; |
| } |
| }()); |
| } |