1 /*

     2 Copyright (c) 2009, Yahoo! Inc. All rights reserved.

     3 Code licensed under the BSD License:

     4 http://developer.yahoo.net/yui/license.txt

     5 version: 3.0.0b1

     6 build: 1163

     7 */

     8 YUI.add('json-stringify', function(Y) {

     9 

    10 /**

    11  * Provides Y.JSON.stringify method for converting objects to JSON strings.

    12  *

    13  * @module json

    14  * @submodule json-stringify

    15  * @for JSON

    16  * @static

    17  */

    18 var _toString = Object.prototype.toString,

    19     Lang      = Y.Lang,

    20     isFunction= Lang.isFunction,

    21     isArray   = Lang.isArray,

    22     type      = Lang.type,

    23     STRING    = 'string',

    24     NUMBER    = 'number',

    25     BOOLEAN   = 'boolean',

    26     OBJECT    = 'object',

    27     ARRAY     = 'array',

    28     REGEXP    = 'regexp',

    29     ERROR     = 'error',

    30     NULL      = 'null',

    31     DATE      = 'date',

    32     EMPTY     = '',

    33     OPEN_O    = '{',

    34     CLOSE_O   = '}',

    35     OPEN_A    = '[',

    36     CLOSE_A   = ']',

    37     COMMA     = ',',

    38     COMMA_CR  = ",\n",

    39     CR        = "\n",

    40     COLON     = ':',

    41     COLON_SP  = ': ',

    42     QUOTE     = '"';

    43 

    44 Y.mix(Y.namespace('JSON'),{

    45     /**

    46      * Regex used to capture characters that need escaping before enclosing

    47      * their containing string in quotes.

    48      *

    49      * @property _SPECIAL_CHARS

    50      * @type {RegExp}

    51      * @protected

    52      */

    53     _SPECIAL_CHARS : /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,

    54 

    55     /**

    56      * Character substitution map for common escapes and special characters.

    57      *

    58      * @property _CHARS

    59      * @type {Object}

    60      * @static

    61      * @protected

    62      */

    63     _CHARS : {

    64         '\b': '\\b',

    65         '\t': '\\t',

    66         '\n': '\\n',

    67         '\f': '\\f',

    68         '\r': '\\r',

    69         '"' : '\\"',

    70         '\\': '\\\\'

    71     },

    72 

    73     /**

    74      * Serializes a Date instance as a UTC date string.  Used internally by

    75      * stringify.  Override this method if you need Dates serialized in a

    76      * different format.

    77      *

    78      * @method dateToString

    79      * @param d {Date} The Date to serialize

    80      * @return {String} stringified Date in UTC format YYYY-MM-DDTHH:mm:SSZ

    81      * @static

    82      */

    83     dateToString : function (d) {

    84         function _zeroPad(v) {

    85             return v < 10 ? '0' + v : v;

    86         }

    87 

    88         return QUOTE + d.getUTCFullYear()   + '-' +

    89               _zeroPad(d.getUTCMonth() + 1) + '-' +

    90               _zeroPad(d.getUTCDate())      + 'T' +

    91               _zeroPad(d.getUTCHours())     + COLON +

    92               _zeroPad(d.getUTCMinutes())   + COLON +

    93               _zeroPad(d.getUTCSeconds())   + 'Z' + QUOTE;

    94     },

    95 

    96     /**

    97      * <p>Converts an arbitrary value to a JSON string representation.</p>

    98      *

    99      * <p>Objects with cyclical references will trigger an exception.</p>

   100      *

   101      * <p>If a whitelist is provided, only matching object keys will be

   102      * included.  Alternately, a replacer function may be passed as the

   103      * second parameter.  This function is executed on every value in the

   104      * input, and its return value will be used in place of the original value.

   105      * This is useful to serialize specialized objects or class instances.</p>

   106      *

   107      * <p>If a positive integer or non-empty string is passed as the third

   108      * parameter, the output will be formatted with carriage returns and

   109      * indentation for readability.  If a String is passed (such as "\t") it

   110      * will be used once for each indentation level.  If a number is passed,

   111      * that number of spaces will be used.</p>

   112      *

   113      * @method stringify

   114      * @param o {MIXED} any arbitrary value to convert to JSON string

   115      * @param w {Array|Function} (optional) whitelist of acceptable object

   116      *                  keys to include, or a replacer function to modify the

   117      *                  raw value before serialization

   118      * @param ind {Number|String} (optional) indentation character or depth of

   119      *                  spaces to format the output.

   120      * @return {string} JSON string representation of the input

   121      * @static

   122      */

   123     stringify : function (o,w,ind) {

   124 

   125         var m      = Y.JSON._CHARS,

   126             str_re = Y.JSON._SPECIAL_CHARS,

   127             rep    = isFunction(w) ? w : null,

   128             pstack = [], // Processing stack used for cyclical ref protection

   129             _date  = Y.JSON.dateToString, // Use configured date serialization

   130             format = _toString.call(ind).match(/String|Number/);

   131 

   132         if (rep || typeof w !== 'object') {

   133             w = undefined;

   134         }

   135 

   136         if (format) {

   137             // String instances and primatives are left alone.  String objects

   138             // coerce for the indenting operations.

   139             if (format[0] === 'Number') {

   140 

   141                 // force numeric indent values between {0,100} per the spec

   142                 // This also converts Number instances to primative

   143                 ind = new Array(Math.min(Math.max(0,ind),100)+1).join(" ");

   144             }

   145 

   146             // turn off formatting for 0 or empty string

   147             format = ind;

   148         }

   149 

   150         // escape encode special characters

   151         function _char(c) {

   152             if (!m[c]) {

   153                 m[c]='\\u'+('0000'+(+(c.charCodeAt(0))).toString(16)).slice(-4);

   154             }

   155             return m[c];

   156         }

   157 

   158         // Enclose the escaped string in double quotes

   159         function _string(s) {

   160             return QUOTE + s.replace(str_re, _char) + QUOTE;

   161         }

   162 

   163         // Check for cyclical references

   164         function _cyclicalTest(o) {

   165             for (var i = pstack.length - 1; i >= 0; --i) {

   166                 if (pstack[i] === o) {

   167                     throw new Error("JSON.stringify. Cyclical reference");

   168                 }

   169             }

   170             return false;

   171         }

   172 

   173         function _indent(s) {

   174             return s.replace(/^/gm,ind);

   175         }

   176 

   177         function _object(o,arr) {

   178             // Add the object to the processing stack

   179             pstack.push(o);

   180 

   181             var a = [],

   182                 colon = format ? COLON_SP : COLON,

   183                 i, j, len, k, v;

   184 

   185             if (arr) { // Array

   186                 for (i = o.length - 1; i >= 0; --i) {

   187                     a[i] = _stringify(o,i) || NULL;

   188                 }

   189             } else {   // Object

   190                 // If whitelist provided, take only those keys

   191                 k = isArray(w) ? w : Y.Object.keys(o);

   192 

   193                 for (i = 0, j = 0, len = k.length; i < len; ++i) {

   194                     if (typeof k[i] === STRING) {

   195                         v = _stringify(o,k[i]);

   196                         if (v) {

   197                             a[j++] = _string(k[i]) + colon + v;

   198                         }

   199                     }

   200                 }

   201             }

   202 

   203             // remove the array from the stack

   204             pstack.pop();

   205 

   206             if (format && a.length) {

   207                 return arr ?

   208                     OPEN_A + CR + _indent(a.join(COMMA_CR)) + CR + CLOSE_A :

   209                     OPEN_O + CR + _indent(a.join(COMMA_CR)) + CR + CLOSE_O;

   210             } else {

   211                 return arr ?

   212                     OPEN_A + a.join(COMMA) + CLOSE_A :

   213                     OPEN_O + a.join(COMMA) + CLOSE_O;

   214             }

   215         }

   216 

   217         // Worker function.  Fork behavior on data type and recurse objects.

   218         function _stringify(h,key) {

   219             var o = isFunction(rep) ? rep.call(h,key,h[key]) : h[key],

   220                 t = type(o);

   221 

   222             if (t === OBJECT) {

   223                 if (/String|Number|Boolean/.test(_toString.call(o))) {

   224                     o = o.valueOf();

   225                     t = type(o);

   226                 }

   227             }

   228 

   229             switch (t) {

   230                 case STRING  : return _string(o);

   231                 case NUMBER  : return isFinite(o) ? o+EMPTY : NULL;

   232                 case BOOLEAN : return o+EMPTY;

   233                 case DATE    : return _date(o);

   234                 case NULL    : return NULL;

   235                 case ARRAY   : _cyclicalTest(o); return _object(o,true);

   236                 case REGEXP  : // intentional fall through

   237                 case ERROR   : // intentional fall through

   238                 case OBJECT  : _cyclicalTest(o); return _object(o);

   239                 default      : return undefined;

   240             }

   241         }

   242 

   243         // process the input

   244         return _stringify({'':o},EMPTY);

   245     }

   246 });

   247 

   248 

   249 }, '3.0.0b1' );