Guid class for generating and working with Guid-formatted strings...

gistfile1.js

/**
 *  class Guid
 **/
var Guid = Class.create((function() {
	var _value;
	return {
		/**
		 *  new Guid(value);
		 *
		 *  - value ([[String]]): Valid guid-formatted string.
		 **/
		initialize: function(value) {
			if (Guid.isGuid(value)) {
				_value = value.toString(); return;
			}
			throw "Invalid GUID value: \"#{value}\"".interpolate({value: value});
		},

		/**
		 *  Guid#isEmpty() -> Boolean
		 *
		 *  Checks if the instance is empty.
		 **/
		isEmpty: function() {
			return _value == Guid.Empty;
		},
		
		/**
		 *  Guid#equals(guid) -> Boolean
		 *  - guid (Object): Value to compare against.
		 *
		 *  Checks if the provided guid is the "same" as this instance. Comparison
		 *  will return true if specified object's toString method returns the same
		 *  value as this instance's value.
		 **/
		equals: function(guid) {
			return Guid.isGuid(guid) && this == guid;
		},

		/**
		 *  Guid#toString() -> String
		 *
		 *  Returns the Guid is [[String]] format.
		 **/
		toString: function() { return _value; }
	};
})());

Object.extend(Guid, (function() {
	function _gen(count) {
		// Private function for creating guid parts.
		var out = "";
		for (var i=0; i<count; i++) {
			out += (((1+Math.random())*0x10000)|0).toString(16).substring(1);
		}
		return out;
	}
	return {
		Empty: "00000000-0000-0000-0000-000000000000",

		Validator: new RegExp("[a-z0-9]{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{12}", "i"),

		/**
		 *  Guid.isGuid(value) -> Boolean
		 *  - value (Object): The value to check.
		 *
		 *  Checks if the value represents a valid Guid. Value can be any object
		 *  that returns a valid Guid-formatted string with its toString method.
		 **/
		isGuid: function(value) {
			return value && Guid.Validator.test(value.toString());
		},

		/**
		 *  Guid.create() -> Guid
		 *
		 *  Creates a new Guid object with a pseudo-unique value.
		 **/
		create: function() {
			return new Guid([_gen(2), _gen(1), _gen(1), _gen(1), _gen(3)].join("-"));
		}
	};
})());