source: Dev/trunk/src/client/dojox/uuid/generateRandomUuid.js @ 532

define(['./_base'], function(){

dojox.uuid.generateRandomUuid = function(){
        // summary:
        //              This function generates random UUIDs, meaning "version 4" UUIDs.
        // description:
        //              A typical generated value would be something like this:
        //              "3b12f1df-5232-4804-897e-917bf397618a"
        //
        //              For more information about random UUIDs, see sections 4.4 and
        //              4.5 of RFC 4122: http://tools.ietf.org/html/rfc4122#section-4.4
        //
        //              This generator function is designed to be small and fast,
        //              but not necessarily good.
        //
        //              Small: This generator has a small footprint. Once comments are
        //              stripped, it's only about 25 lines of code, and it doesn't
        //              dojo.require() any other modules.
        //
        //              Fast: This generator can generate lots of new UUIDs fairly quickly
        //              (at least, more quickly than the other dojo UUID generators).
        //
        //              Not necessarily good: We use Math.random() as our source
        //              of randomness, which may or may not provide much randomness.
        // examples:
        //              var string = dojox.uuid.generateRandomUuid();
        var HEX_RADIX = 16;

        function _generateRandomEightCharacterHexString(){
                // Make random32bitNumber be a randomly generated floating point number
                // between 0 and (4,294,967,296 - 1), inclusive.
                var random32bitNumber = Math.floor( (Math.random() % 1) * Math.pow(2, 32) );
                var eightCharacterHexString = random32bitNumber.toString(HEX_RADIX);
                while(eightCharacterHexString.length < 8){
                        eightCharacterHexString = "0" + eightCharacterHexString;
                }
                return eightCharacterHexString; // for example: "3B12F1DF"
        }

        var hyphen = "-";
        var versionCodeForRandomlyGeneratedUuids = "4"; // 8 == binary2hex("0100")
        var variantCodeForDCEUuids = "8"; // 8 == binary2hex("1000")
        var a = _generateRandomEightCharacterHexString();
        var b = _generateRandomEightCharacterHexString();
        b = b.substring(0, 4) + hyphen + versionCodeForRandomlyGeneratedUuids + b.substring(5, 8);
        var c = _generateRandomEightCharacterHexString();
        c = variantCodeForDCEUuids + c.substring(1, 4) + hyphen + c.substring(4, 8);
        var d = _generateRandomEightCharacterHexString();
        var returnValue = a + hyphen + b + hyphen + c + d;
        returnValue = returnValue.toLowerCase();
        return returnValue; // String
};

return dojox.uuid.generateRandomUuid;

});