A better way to use localStorage and sessionStorage
A feature-filled and friendly way to take advantage of localStorage and sessionStorage (JSON, namespacing, extensions, etc).
Download: store2.min.js or store2.js
NPM: npm install store2
Bower: bower install store2
NuGet: Install-Package store2
The main store function can handle set, get, setAll, getAll and clear
actions directly. Respectively, these are called like so:
store(key, data); // sets stringified data under key
store(key); // gets and parses data stored under key
store({key: data, key2: data2}); // sets all key/data pairs in the object
store(); // gets all stored key/data pairs as an object
store(false); // clears all items from storage
There are also more explicit and versatile functions available:
store.set(key, data[, overwrite]); // === store(key, data);
store.setAll(data[, overwrite]); // === store({key: data, key2: data});
store.get(key[, alt]); // === store(key);
store.getAll(); // === store();
store.clear(); // === store(false);
store.has(key); // returns true or false
store.remove(key); // removes key and its data
store.each(callback); // called with key and data args, return false to exit early
store.keys(); // returns array of keys
store.size(); // number of keys, not length of data
store.clearAll(); // clears *ALL* areas (but still namespace sensitive)
Passing in false for the optional overwrite parameters will cause set actions to be skipped
if the storage already has a value for that key. All set action methods return the previous value
for that key, by default. If overwrite is false and there is a previous value, the unused new
value will be returned.
All of these use the browser's localStorage (aka "local"). Using sessionStorage merely requires
calling the same functions on store.session:
store.session("addMeTo", "sessionStorage");
store.local({lots: 'of', data: 'altogether'});// store.local === store :)
All the specific get, set, etc. functions are available on both store.session and store.local, as well as any other storage facility registered via store.area(name, customStorageObject) by an extension, where customStorageObject must implement the Storage interface. This is how store.old.js extends store.js to support older versions of IE and Firefox.
If you want to put stored data from different pages or areas of your site into separate namespaces,
the store.namespace(ns) function is your friend:
var cart = store.namespace('cart');
cart('total', 23.25);// stores in localStorage as 'cart.total'
console.log(store('cart.total') == cart('total'));// logs true
console.log(store.cart.getAll());// logs {total: 23.25}
cart.session('group', 'toys');// stores in sessionStorage as 'cart.group'
The namespace provides the same exact API as store but silently adds/removes the namespace prefix as needed.
It also makes the namespaced API accessible directly via store[namespace] (e.g. store.cart) as long as it
does not conflict with an existing part of the store API.
The 'namespace' function is one of two "extra" functions that are also part of the "store API":
store.namespace(prefix[, noSession]);// returns a new store API that prefixes all key-based functions
store.isFake();// is this storage persistent? (e.g. is this old IE?)
If localStorage or sessionStorage are unavailable, they will be faked to prevent errors, but data stored will NOT persist beyond the life of the current document/page. Use the store.old.js extension to add persistent backing for the store API in older browsers.
These mostly could use further documentation and abuse...er...testing. Contributions are welcome!
set() callsWhen i went to publish this on NPM i discovered another store.js by Marcus Westin. To my surprise, even our APIs had notable overlap. His has fewer features and includes superior support for IE 6/7 in the main lib. I contacted him with the idea of merging the featuresets, but we agreed it wouldn't work. He sees his library as a temporary polyfill meant to fade away with IE 6/7. This project is meant to always be useful, as a better way to use localStorage, with polyfilling as an extension. I do hope to incorporate IE 6/7 improvements from the other store.js into store.old.js at some point, but it is not a priority.
To minimize confusion, i will be publishing the library as 'store2',
but the main function will always be store.
My apologies for the confusion caused while i was publishing this as another 'store'.