storage.js

/*global define */
/*jshint expr:true */

define([], function () {

  'use strict';

  var hasLocalStorageSupport = (function () {
        var str = 'storage-test-' + Math.random();
        try {
            localStorage.setItem(str, str);
            localStorage.removeItem(str);
            return true;
        } catch (e) {
            return false;
        }
    }());

    var persist = hasLocalStorageSupport ? function (namespace, data) {
        localStorage.setItem(namespace, JSON.stringify(data));
    } : function () {};

    return function (namespace) {
        if (!namespace) {
            throw new Error('Namespace is required');
        }
        
        var data = {};
        try {
            data = JSON.parse(localStorage.getItem(namespace)) || {};
        }
        catch (e) {}
        return {
            'clear': function () {
                data = {};
                persist(namespace, data);
            },
            'set': function (key, value) {
                data[key] = value;
                persist(namespace, data);
            },
            'get': function (path) {
                return path.split('.').reduce(function (memo, val) {
                    return memo ? memo[val] : void 0;
                }, data);
            },
            'export': function () {
                return data;
            }
        }
    };

});