json.js revision 80c2303f32a65a670907dba765dfde42dc319087
/**
* The JSON Utility provides methods to serialize JavaScript objects into
* JSON strings and parse JavaScript objects from strings containing JSON data.
* Three modules are available for inclusion:
* <ol>
* <li>1. <code>json-parse</code> for parsing JSON strings into native JavaScript data</li>
* <li>2. <code>json-stringify</code> for stringification of JavaScript objects into JSON strings</li>
* <li>3. <code>json</code> for both parsing and stringification</li>
* </ol>
*
* Both <code>json-parse</code> and <code>json-stringify</code> create functions in a static JSON class under your YUI instance (e.g. Y.JSON.parse(..)).
* @module json
* @class JSON
* @static
*/
/**
* Provides Y.JSON.parse method to take JSON strings and return native
* JavaScript objects.
* @module json
* @submodule json-parse
* @for JSON
* @static
*/
// All internals kept private for security reasons
/*
* Alias to native browser implementation of the JSON object if available.
*
* @property Native
* @type {Object}
* @private
*/
/**
* Replace certain Unicode characters that JavaScript may handle incorrectly
* during eval--either by deleting them or treating them as line
* endings--with escape sequences.
* IMPORTANT NOTE: This regex will be used to modify the input if a match is
* found.
* @property _UNICODE_EXCEPTIONS
* @type {RegExp}
* @private
*/
_UNICODE_EXCEPTIONS = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
/**
* First step in the validation. Regex used to replace all escape
* sequences (i.e. "\\", etc) with '@' characters (a non-JSON character).
* @property _ESCAPES
* @type {RegExp}
* @private
*/
_ESCAPES = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g,
/**
* Second step in the validation. Regex used to replace all simple
* values with ']' characters.
* @property _VALUES
* @type {RegExp}
* @private
*/
/**
* Third step in the validation. Regex used to remove all open square
* brackets following a colon, comma, or at the beginning of the string.
* @property _BRACKETS
* @type {RegExp}
* @private
*/
_BRACKETS = /(?:^|:|,)(?:\s*\[)+/g,
/**
* Final step in the validation. Regex used to test the string left after
* all previous replacements for invalid characters.
* @property _INVALID
* @type {RegExp}
* @private
*/
_INVALID = /[^\],:{}\s]/,
/**
* Test for JSON string of simple data string, number, boolean, or null.
* E.g. '"some string"', "true", "false", "null", or numbers "-123e+7"
*
* @property _SIMPLE
* @type {RegExp}
* @protected
*/
/**
* Replaces specific unicode characters with their appropriate \unnnn
* format. Some browsers ignore certain characters during eval.
*
* @method escapeException
* @param c {String} Unicode character
* @return {String} the \unnnn escapement of the character
* @private
*/
_escapeException = function (c) {
return '\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
},
/**
* Traverses nested objects, applying a reviver function to each (key,value)
* from the scope if the key:value's containing object. The value returned
* from the function will replace the original value in the key:value pair.
* If the value returned is undefined, the key will be omitted from the
* returned object.
* @method _revive
* @param data {MIXED} Any JavaScript data
* @param reviver {Function} filter or mutation function
* @return {MIXED} The results of the filtered data
* @private
*/
_revive = function (data, reviver) {
var walk = function (o,key) {
var k,v,value = o[key];
if (value && typeof value === 'object') {
for (k in value) {
if (value.hasOwnProperty(k)) {
v = walk(value, k);
if (v === undefined) {
delete value[k];
} else {
value[k] = v;
}
}
}
}
return reviver.call(o,key,value);
};
return typeof reviver === 'function' ? walk({'':data},'') : data;
},
/**
* Parse a JSON string, returning the native JavaScript representation.
* @param s {string} JSON string data
* @param reviver {function} (optional) function(k,v) passed each key value
* pair of object literals, allowing pruning or altering values
* @return {MIXED} the native JavaScript representation of the JSON string
* @throws SyntaxError
* @method parse
* @static
* @public
*/
// JavaScript implementation in lieu of native browser support. Based on
// the json2.js library from http://json.org
_parse = function (s,reviver) {
if (typeof s === 'string') {
// Replace certain Unicode characters that are otherwise handled
// incorrectly by some browser implementations.
// NOTE: This modifies the input if such characters are found!
s = s.replace(_UNICODE_EXCEPTIONS, _escapeException);
// Test for any remaining invalid characters
if (!_INVALID.test(s.replace(_ESCAPES,'@').
replace(_VALUES,']').
replace(_BRACKETS,''))) {
// Eval the text into a JavaScript data structure, apply any
// reviver function, and return
return _revive( eval('(' + s + ')'), reviver );
}
}
throw new SyntaxError('JSON.parse');
},
test;
// Test the level of native browser support
if (Native && Object.prototype.toString.call(Native) === '[object JSON]') {
try {
test = Native.parse('{"x":1}', function (k,v) {return k=='x' ? 2 : v;});
switch (test.x) {
case 1 : // Reviver not supported (currently FF3.1b2)
_parse = function (s,reviver) {
return _SIMPLE.test(s) ?
eval('(' + s + ')') :
_revive(Native.parse(s), reviver);
};
break;
case 2 : // Full support (currently IE8)
_parse = function (s, reviver) {
return Native.parse(s, reviver);
};
break;
// default is JS implementation
}
}
catch (e) {} // defer to JS implementation
}
Y.mix(Y.namespace('JSON'),{ parse : _parse });
}, '@VERSION@' );
YUI.add('json-stringify', function(Y) {
/**
* Provides Y.JSON.stringify method for converting objects to JSON strings.
* @module json
* @submodule json-stringify
* @for JSON
* @static
*/
var _toString = Object.prototype.toString,
Lang = Y.Lang,
isFunction= Lang.isFunction,
isArray = Lang.isArray,
type = Lang.type,
STRING = 'string',
NUMBER = 'number',
BOOLEAN = 'boolean',
OBJECT = 'object',
ARRAY = 'array',
REGEXP = 'regexp',
ERROR = 'error',
NULL = 'null',
DATE = 'date',
EMPTY = '',
OPEN_O = '{',
CLOSE_O = '}',
OPEN_A = '[',
CLOSE_A = ']',
COMMA = ',',
COMMA_CR = ",\n",
CR = "\n",
COLON = ':',
COLON_SP = ': ',
QUOTE = '"',
Native = Y.config.win.JSON,
stringify = function (o,w,ind) {
var m = Y.JSON._CHARS,
str_re = Y.JSON._SPECIAL_CHARS,
rep = isFunction(w) ? w : null,
pstack = [], // Processing stack used for cyclical ref protection
_date = Y.JSON.dateToString, // Use configured date serialization
format = _toString.call(ind).match(/String|Number/);
w = undefined;
}
if (format) {
// String instances and primatives are left alone. String objects
// coerce for the indenting operations.
if (format[0] === 'Number') {
// force numeric indent values between {0,100} per the spec
// This also converts Number instances to primative
ind = new Array(Math.min(Math.max(0,ind),100)+1).join(" ");
}
// turn off formatting for 0 or empty string
format = ind;
}
// escape encode special characters
function _char(c) {
if (!m[c]) {
m[c]='\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);
}
return m[c];
}
// Enclose the escaped string in double quotes
function _string(s) {
return QUOTE + s.replace(str_re, _char) + QUOTE;
}
// Check for cyclical references
function _cyclicalTest(o) {
for (var i = pstack.length - 1; i >= 0; --i) {
if (pstack[i] === o) {
throw new Error("JSON.stringify. Cyclical reference");
}
}
return false;
}
function _indent(s) {
return s.replace(/^/gm,ind);
}
function _object(o,arr) {
// Add the object to the processing stack
pstack.push(o);
var a = [],
colon = format ? COLON_SP : COLON,
i, j, len, k, v;
if (arr) { // Array
for (i = o.length - 1; i >= 0; --i) {
a[i] = _stringify(o,i) || NULL;
}
} else { // Object
// If whitelist provided, take only those keys
k = isArray(w) ? w : Y.Object.keys(o);
for (i = 0, j = 0, len = k.length; i < len; ++i) {
if (typeof k[i] === STRING) {
v = _stringify(o,k[i]);
if (v) {
a[j++] = _string(k[i]) + colon + v;
}
}
}
}
// remove the array from the stack
pstack.pop();
if (format && a.length) {
return arr ?
OPEN_A + CR + _indent(a.join(COMMA_CR)) + CR + CLOSE_A :
OPEN_O + CR + _indent(a.join(COMMA_CR)) + CR + CLOSE_O;
} else {
return arr ?
OPEN_A + a.join(COMMA) + CLOSE_A :
OPEN_O + a.join(COMMA) + CLOSE_O;
}
}
// Worker function. Fork behavior on data type and recurse objects.
function _stringify(h,key) {
var o = isFunction(rep) ? rep.call(h,key,h[key]) : h[key],
t = type(o);
if (t === OBJECT) {
if (/String|Number|Boolean/.test(_toString.call(o))) {
o = o.valueOf();
t = type(o);
}
}
switch (t) {
case STRING : return _string(o);
case NUMBER : return isFinite(o) ? o+EMPTY : NULL;
case BOOLEAN : return o+EMPTY;
case DATE : return _date(o);
case NULL : return NULL;
case ARRAY : _cyclicalTest(o); return _object(o,true);
case REGEXP : // intentional fall through
case ERROR : // intentional fall through
case OBJECT : _cyclicalTest(o); return _object(o);
default : return undefined;
}
}
// process the input
return _stringify({'':o},EMPTY);
},
test;
// Test for fully functional native implementation
try {
test = Native.stringify([function () {}, { a:1,b:2 }],['b'],'x').
replace(/ +/gm,'');
if (Native.stringify(1) === "1" &&
test === "[\nxnull,\nx{\nxx\"b\":2\nx}\n]") {
stringify = Native.stringify;
}
}
catch (e) {} // defer to JS implementation
}
/**
* Regex used to capture characters that need escaping before enclosing
* their containing string in quotes.
* @property _SPECIAL_CHARS
* @type {RegExp}
* @private
*/
_SPECIAL_CHARS : /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
/**
* Character substitution map for common escapes and special characters.
* @property _CHARS
* @type {Object}
* @static
* @private
*/
_CHARS : {
'\b': '\\b',
'\t': '\\t',
'\n': '\\n',
'\f': '\\f',
'\r': '\\r',
'"' : '\\"',
'\\': '\\\\'
},
/**
* Serializes a Date instance as a UTC date string. Used internally by
* stringify. Override this method if you need Dates serialized in a
* different format.
* @method dateToString
* @param d {Date} The Date to serialize
* @return {String} stringified Date in UTC format YYYY-MM-DDTHH:mm:SSZ
* @static
*/
dateToString : function (d) {
function _zeroPad(v) {
return v < 10 ? '0' + v : v;
}
return QUOTE + d.getUTCFullYear() + '-' +
_zeroPad(d.getUTCMonth() + 1) + '-' +
_zeroPad(d.getUTCDate()) + 'T' +
_zeroPad(d.getUTCHours()) + COLON +
_zeroPad(d.getUTCMinutes()) + COLON +
_zeroPad(d.getUTCSeconds()) + 'Z' + QUOTE;
},
/**
* Converts an arbitrary value to a JSON string representation.
* Cyclical object or array references are replaced with null.
* If a whitelist is provided, only matching object keys will be included.
* If a positive integer or non-empty string is passed as the third
* parameter, the output will be formatted with carriage returns and
* indentation for readability. If a String is passed (such as "\t") it
* will be used once for each indentation level. If a number is passed,
* that number of spaces will be used.
* @method stringify
* @param o {MIXED} any arbitrary object to convert to JSON string
* @param w {Array|Function} (optional) whitelist of acceptable object
* keys to include, or a replacer function to modify the
* raw value before serialization
* @param ind {Number|String} (optional) indentation character or depth of
* spaces to format the output.
* @return {string} JSON string representation of the input
* @static
* @public
*/
stringify : stringify
});