daw/js/json.js

/*
 * jQuery JSON Plugin
 * version: 1.0 (2008-04-17)
 *
 * This document is licensed as free software under the terms of the
 * MIT License: http://www.opensource.org/licenses/mit-license.php
 *
 * Brantley Harris technically wrote this plugin, but it is based somewhat
 * on the JSON.org website's http://www.json.org/json2.js, which proclaims:
 * "NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.", a sentiment that
 * I uphold.  I really just cleaned it up.
 *
 * It is also based heavily on MochiKit's serializeJSON, which is
 * copywrited 2005 by Bob Ippolito.
 */

(function($) {
    function toIntegersAtLease(n)
    // Format integers to have at least two digits.
    {
        return n < 10 ? '0' + n : n;
    }

    Date.prototype.toJSON = function(date)
    // Yes, it polutes the Date namespace, but we'll allow it here, as
    // it's damned usefull.
    {
        return this.getUTCFullYear()   + '-' +
             toIntegersAtLease(this.getUTCMonth()) + '-' +
             toIntegersAtLease(this.getUTCDate());
    };

    var escapeable = /["\\\x00-\x1f\x7f-\x9f]/g;
    var meta = {    // table of character substitutions
            '\b': '\\b',
            '\t': '\\t',
            '\n': '\\n',
            '\f': '\\f',
            '\r': '\\r',
            '"' : '\\"',
            '\\': '\\\\'
        };

    $.quoteString = function(string)
    // Places quotes around a string, inteligently.
    // 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.
    {
        //if (escapeable.test(string))
        //{
            return '"' + string.replace(escapeable, function (a)
            {
                var c = meta[a];
                if (typeof c === 'string') {
                    return c;
                }
                c = a.charCodeAt();
                return '\\u00' + Math.floor(c / 16).toString(16) + (c % 16).toString(16);
            }) + '"';
        //}
        //else{
        //    string = string.replace('\n','\\n');
        //}
        return '"' + string + '"';
    };

    $.toJSON = function(o, compact)
    {
        var type = typeof(o);

        if (type == "undefined")
            return "undefined";
        else if (type == "number" || type == "boolean")
            return o + "";
        else if (o === null)
            return "null";

        // Is it a string?
        if (type == "string")
        {
            var str = $.quoteString(o);
            return str;
        }

        // Does it have a .toJSON function?
        if (type == "object" && typeof o.toJSON == "function")
            return o.toJSON(compact);

        // Is it an array?
        if (type != "function" && typeof(o.length) == "number")
        {
            var ret = [];
            for (var i = 0; i < o.length; i++) {
                ret.push( $.toJSON(o[i], compact) );
            }
            if (compact)
                return "[" + ret.join(",") + "]";
            else
                return "[" + ret.join(", ") + "]";
        }

        // If it's a function, we have to warn somebody!
        if (type == "function") {
            throw new TypeError("Unable to convert object of type 'function' to json.");
        }

        // It's probably an object, then.
        var ret = [];
        for (var k in o) {
            var name;
            type = typeof(k);

            if (type == "number")
                name = '"' + k + '"';
            else if (type == "string")
                name = $.quoteString(k);
            else
                continue;  //skip non-string or number keys

            var val = $.toJSON(o[k], compact);
            if (typeof(val) != "string") {
                // skip non-serializable values
                continue;
            }

            if (compact)
                ret.push(name + ":" + val);
            else
                ret.push(name + ": " + val);
        }
        return "{" + ret.join(", ") + "}";
    };

    $.compactJSON = function(o)
    {
        return $.toJSON(o, true);
    };

    $.evalJSON = function(src)
    // Evals JSON that we know to be safe.
    {
        return eval("(" + src + ")");
    };

    $.secureEvalJSON = function(src)
    // Evals JSON in a way that is *more* secure.
    {
        var filtered = src;
        filtered = filtered.replace(/\\["\\\/bfnrtu]/g, '@');
        filtered = filtered.replace(/"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g, ']');
        filtered = filtered.replace(/(?:^|:|,)(?:\s*\[)+/g, '');

        if (/^[\],:{}\s]*$/.test(filtered))
            return eval("(" + src + ")");
        else
            throw new SyntaxError("Error parsing JSON, source is not valid.");
    };
})(jQuery);