if (CacheProvider.hasLocalStorage) { Storage.prototype.setObject = function(key, value) { this.setItem(key, JSON.stringify(value)); }; Storage.prototype.getObject = function(key) { return JSON.parse(this.getItem(key)); }; }

CacheProvider.prototype = { /** * {String} k - the key * {Boolean} local - get this from local storage? * {Boolean} o - is the value you put in local storage an object? */ get: function(k, local, o) { if (local && CacheProvider.hasLocalStorage) { var action = o ? 'getObject' : 'getItem'; return localStorage[action](k) || undefined; } else { return this._cache[k] || undefined; } }, /** * {String} k - the key * {Object} v - any kind of value you want to store * however only objects and strings are allowed in local storage * {Boolean} local - put this in local storage */ set: function(k, v, local) { if (local && CacheProvider.hasLocalStorage) { if (typeof v !== 'string')) { // make assumption if it's not a string, then we're storing an object localStorage.setObject(k, v); } else { try { localStorage.setItem(k, v); } catch (ex) { if (ex.name == 'QUOTA_EXCEEDED_ERR') { // developer needs to figure out what to start invalidating throw new Exception(v); return; } } } } else { // put in our local object this._cache[k] = v; } // return our newly cached item return v; }, /** * {String} k - the key * {Boolean} local - put this in local storage * {Boolean} o - is this an object you want to put in local storage? */ clear: function(k, local, o) { if (local && CacheProvider.hasLocalStorage) { localStorage.removeItem(k); } // delete in both caches - doesn't hurt. delete this._cache[k]; } };

var cache = new CacheProvider; window.getElementsByClassName = getElementsByClassName || function(c) { var reg = cache.get(c) || cache.set(c, new RegExp("(?:^|s+)" + c + "(?:s+|$)")); var elements = document.getElementsByTagName('*'); var results = []; for (var i = 0; i < elements.length; i++) { if (elements[i].className.match(reg)) { results.push(elements[i]); } } return results; };

var i18nCache = new CacheProvider; if (i18nCache.get('topnav')) { $('#nav').html(i18nCache.get('topnav')); } else { ajax('top-nav.tmpl', function(html) { i18nCache.set('topnav', html); $('#nav').html(i18nCache.get('topnav')); }); }