json.js

// NOTE: json2.js uses fallbacks to the existing JSON implementations. So we can't rely on it in our client code.
// This is an isolated implementation of JSON that does not rely on any external stuff (prototypes, existing JSON
// implementations, etc.). The Serialization/deserialization logic is borrowed from http://json.org/json2.js.
function f (n) {
    // Format integers to have at least two digits.
    return n < 10 ? '0' + n : n;
}

var cx        = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g;
var escapable = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g;

var gap;
var indent;

var meta = {    // table of character substitutions
    '\b': '\\b',
    '\t': '\\t',
    '\n': '\\n',
    '\f': '\\f',
    '\r': '\\r',
    '"':  '\\"',
    '\\': '\\\\'
};

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') {
        //NOTE: determine exact object type instead of relying on prototype.toJSON like in original json2.js
        var objToStrValue = Object.prototype.toString.apply(value);
        if (objToStrValue === '[object String]' ||
            objToStrValue === '[object Number]' ||
            objToStrValue === '[object Boolean]') {
            value = value.valueOf();
        }
        else if (objToStrValue === '[object Date]') {
            value = isFinite(this.valueOf())
                ? this.getUTCFullYear() + '-' +
                  f(this.getUTCMonth() + 1) + '-' +
                  f(this.getUTCDate()) + 'T' +
                  f(this.getUTCHours()) + ':' +
                  f(this.getUTCMinutes()) + ':' +
                  f(this.getUTCSeconds()) + 'Z'
                : null;
        }
    }

    // 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;
            }

            // Iterate through all of the keys in the object.
            for (k in value) {
                if (Object.prototype.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;
    }
}

function isDOMNode (obj) {
    if (typeof Node === 'object')
        return obj instanceof Node;

    return typeof obj.nodeType === 'number' && typeof obj.nodeName === 'string';
}

function isJQueryObj (obj) {
    return !!(obj && obj.jquery);
}

//Exports
//-------------------------------------------------------------------------------------
exports.stringify = function (value) {
    gap    = '';
    indent = '';

    // Make a fake root object containing our value under the key of ''.
    // Return the result of stringifying the value.
    return str('', { '': value });
}

exports.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.prototype.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');
}

exports.isSerializable = function (value) {
    if (value) {
        //NOTE: jquery object, DOM nodes and functions are disallowed obj types because we can't serialize them correctly
        if (typeof value === 'function' || isJQueryObj(value) || isDOMNode(value))
            return false;

        if (typeof value === 'object') {
            for (var prop in value) {
                if (value.hasOwnProperty(prop) && !exports.isSerializable(value[prop]))
                    return false;
            }
        }
    }

    return true;
}