remotestore

allows domain to share and pool localStorage data

The browser-provided localStorage interface is only available to same-domain pages and is limited to just 5mb of data.

RemoteStore opens the localStorage of a specified domain from any domain, and can pool many domains together to save more data.

How it Works

RemoteStore requires two parts to operate:

1. 1+ HTML "server" page(s) that live in a hidden iframe
2. a JavaScript client library that provides Promise-based access to the hidden frame's localStorage

You first need to copy remotestore.html and remotestore.server.js to a domain you control, preferably one that you don't use for hosting client applications. You can publish more than one to pool localStorage resources. Note that if your page or app runs on HTTPS, then you will need to host the above file on HTTTPS as well. Also note that you should not use an X-Frame-Options iframe policy header when serving the html files.

You then load the remotestore.js library into your app, and point it towards the html "server" file(s) as you spawn an instance of the storage API, passing the constructor the URL(s).

The Interface

Usage:

var store = RemoteStore(strURLofHtmlServerPage); // one common domain w/ String
var store = RemoteStore([strURL1, strURL2, ...]);// pool many domains w/ Array

Promise Methods:

get: 	(key) - fetches a saved value from the RemoteStore(s)'s server's localStorage
set: 	(key, value) - save a value to the least-used localStorage or update an existing value
dir: 	() - fetches an array of stored key names
del: 	(key) - delete a key:value pair by key, yields the size difference

Property Getters:

readyState: [0|1] - have the iframe(s) loaded and checked-in?
used: n -the # of bytes consumed by the data

Examples

Create a new RemoteStore Instance

var myRS = RemoteStore("https://pagedemos.com/store/remotestore.html");

Save key/value paid and show the available byte adjustment

myRS.set("test", "Hello World").then(alert); // shows: -11

List Saved Keys

myRS.dir().then(alert); // shows: test

Load a Saved Key

myRS.get("test").then(alert); // shows: Hello World

Load a Missing Key and get error info

myRS.get("asdf").catch(JSON.stringify).then(alert);
// shows: {"res":"Error, key 'asdf' not set","domain":"https://pagedemos.com","type":"error" ...}

Remove a Saved Key and get the cost adjustment

myRS.del("test").then(alert); // shows: 11