From b48a2704a0d3121ce892ad447a07d0792000d8fe Mon Sep 17 00:00:00 2001 From: Dennis Schafroth Date: Fri, 25 Jun 2010 15:13:01 +0200 Subject: [PATCH] Alternative JSON parsing. --- js/json2.js | 483 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 483 insertions(+) create mode 100644 js/json2.js diff --git a/js/json2.js b/js/json2.js new file mode 100644 index 0000000..0b889a3 --- /dev/null +++ b/js/json2.js @@ -0,0 +1,483 @@ +alert('IMPORTANT: Remove this line from json2.js before deployment.'); +/* + 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 + + + This code should be minified before deployment. + See http://javascript.crockford.com/jsmin.html + + USE YOUR OWN COPY. IT IS EXTREMELY UNWISE TO LOAD CODE FROM SERVERS YOU DO + NOT CONTROL. + + + This file creates a global JSON object containing two methods: stringify + and parse. + + JSON.stringify(value, replacer, space) + value any JavaScript value, usually an object or array. + + replacer an optional parameter that determines how object + values are stringified for objects. It can be a + function or an array of strings. + + space an optional parameter that specifies the indentation + of nested structures. If it is omitted, the text will + be packed without extra whitespace. If it is a number, + it will specify the number of spaces to indent at each + level. If it is a string (such as '\t' or ' '), + it contains the characters used to indent at each level. + + This method produces a JSON text from a JavaScript value. + + When an object value is found, if the object contains a toJSON + method, its toJSON method will be called and the result will be + stringified. A toJSON method does not serialize: it returns the + value represented by the name/value pair that should be serialized, + or undefined if nothing should be serialized. The toJSON method + will be passed the key associated with the value, and this will be + bound to the value + + For example, this would serialize Dates as ISO strings. + + Date.prototype.toJSON = function (key) { + function f(n) { + // Format integers to have at least two digits. + return n < 10 ? '0' + n : n; + } + + return this.getUTCFullYear() + '-' + + f(this.getUTCMonth() + 1) + '-' + + f(this.getUTCDate()) + 'T' + + f(this.getUTCHours()) + ':' + + f(this.getUTCMinutes()) + ':' + + f(this.getUTCSeconds()) + 'Z'; + }; + + You can provide an optional replacer method. It will be passed the + key and value of each member, with this bound to the containing + object. The value that is returned from your method will be + serialized. If your method returns undefined, then the member will + be excluded from the serialization. + + If the replacer parameter is an array of strings, then it will be + used to select the members to be serialized. It filters the results + such that only members with keys listed in the replacer array are + stringified. + + Values that do not have JSON representations, such as undefined or + functions, will not be serialized. Such values in objects will be + dropped; in arrays they will be replaced with null. You can use + a replacer function to replace those with JSON values. + JSON.stringify(undefined) returns undefined. + + The optional space parameter produces a stringification of the + value that is filled with line breaks and indentation to make it + easier to read. + + If the space parameter is a non-empty string, then that string will + be used for indentation. If the space parameter is a number, then + the indentation will be that many spaces. + + Example: + + text = JSON.stringify(['e', {pluribus: 'unum'}]); + // text is '["e",{"pluribus":"unum"}]' + + + text = JSON.stringify(['e', {pluribus: 'unum'}], null, '\t'); + // text is '[\n\t"e",\n\t{\n\t\t"pluribus": "unum"\n\t}\n]' + + text = JSON.stringify([new Date()], function (key, value) { + return this[key] instanceof Date ? + 'Date(' + this[key] + ')' : value; + }); + // text is '["Date(---current time---)"]' + + + JSON.parse(text, reviver) + This method parses a JSON text to produce an object or array. + It can throw a SyntaxError exception. + + The optional reviver parameter is a function that can filter and + transform the results. It receives each of the keys and values, + and its return value is used instead of the original value. + If it returns what it received, then the structure is not modified. + If it returns undefined then the member is deleted. + + Example: + + // Parse the text. Values that look like ISO date strings will + // be converted to Date objects. + + myData = JSON.parse(text, function (key, value) { + var a; + if (typeof value === 'string') { + a = +/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2}(?:\.\d*)?)Z$/.exec(value); + if (a) { + return new Date(Date.UTC(+a[1], +a[2] - 1, +a[3], +a[4], + +a[5], +a[6])); + } + } + return value; + }); + + myData = JSON.parse('["Date(09/09/2001)"]', function (key, value) { + var d; + if (typeof value === 'string' && + value.slice(0, 5) === 'Date(' && + value.slice(-1) === ')') { + d = new Date(value.slice(5, -1)); + if (d) { + return d; + } + } + return value; + }); + + + This is a reference implementation. You are free to copy, modify, or + redistribute. +*/ + +/*jslint evil: true, strict: false */ + +/*members "", "\b", "\t", "\n", "\f", "\r", "\"", JSON, "\\", apply, + call, charCodeAt, getUTCDate, getUTCFullYear, getUTCHours, + getUTCMinutes, getUTCMonth, getUTCSeconds, hasOwnProperty, join, + lastIndex, length, parse, prototype, push, replace, slice, stringify, + test, toJSON, toString, valueOf +*/ + + +// Create a JSON object only if one does not already exist. We create the +// methods in a closure to avoid creating global variables. + +if (!this.JSON) { + this.JSON = {}; +} + +(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 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 JSON.stringify !== 'function') { + JSON.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 JSON.parse !== 'function') { + JSON.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'); + }; + } +}()); -- 1.7.10.4