/* jQuery Session vars v.0.3
 * by Jay Salvat
 * http://www.jaysalvat.com
 * -----------------------------------------------
 * Inspired by an idea from Mario Heiderich
 * http://code.google.com/p/quipt/
 * -----------------------------------------------
 * Requires jquery.json.js by DeadWisdom
 * http://code.google.com/p/jquery-json/
 * -----------------------------------------------
 * CHANGELOG
 * 0.3 -- 11-JUL-08
 * Security improvements
 * Calling manually sessionStart and sessionStop is not required anymore
 * Window.name is keept between pages
 * 0.2 -- 10-JUL-08
 * Now works with functions, objects and arrays
 * 0.1 -- 08-JUL-08
 * First draft
 * -----------------------------------------------
 * USAGE
 * - To Store
 * $(function() {
 *      $.session("myVar, "value");
 * });
 * 
 * - To Read
 * $(function() {
 *      alert( $.session("myVar) );     
 * });
*/
(function($) {
                var sessionData = {};
                var windowName  = "";
                var domain                      = location.href.match(/\w+:\/\/[^\/]+/)[0];
                var referrer            = (document.referrer) ? document.referrer.match(/\w+:\/\/[^\/]+/)[0] : "";

                if(referrer == "" || referrer !== domain) {
                        window.name = window.name.replace("#"+domain+"#", "");
                }
                        
                function loadData() {
                        stored = window.name.split("#"+domain+"#");
                        windowName = window.name = stored[0];
                        if (data = stored[1]) { 
                                $.each(data.split(";"), function(i, data) {
                                                        parts           = data.split("=");
                                                        varName         = parts[0];
                                                        varValue        = unescape(parts[1]);
                                                        sessionData[varName] = varValue;
                                });
                        }
                }
                
                function saveData() {
                        var dataToStore = windowName+"#"+domain+"#";
                        $.each(sessionData, function(varName, varValue) {               
                                        if (varName && varValue) {
                                                dataToStore += ( varName + "=" + escape( varValue ) + ";" );
                                        }
                        });
                        window.name = dataToStore;
                }
                
                $.session = function(name, value) {
                        if (value) {
                                if ($.isFunction(value)) {
                                                value = value();
                                }
                                if ( $.toJSON ) {
                                        sessionData[name] = $.toJSON(value);
                                } else {
                                        sessionData[name] = value;
                                }
                        } else {
                                if ( $.evalJSON ) {
                                        return $.evalJSON(sessionData[name]);
                                } else {
                                        return sessionData[name];
                                }
                        }
                }
                
                $.sessionStop = function() {
                        saveData();
                }               
                
                $.sessionStart = function() {
                        loadData();
                }

                $.sessionStart();
                window.onunload = function() { $.sessionStop(); };
                
        })(jQuery);