Storage is a functional wrapper around localForage. That means it's an asynchronous browser storage with multiple back-ends (IndexedDB, WebSQL, localStorage), which is built for a better offline experience.

The main differences with localForage:

• batch support
• error first node-style callbacks, fixes #55
• simple API inspired by yields/store

$ bower install storage
$ component install ask11/storage
$ npm install ask11-storage --save

Standalone build available as storage.js.

<script src="storage.js"></script>
<script>window.storage('key', fn);</script>

// set
storage('key', 'val', function(err) {});
storage({ key: 'foo', key2: 'val2'}, function(err) {});

// get
storage('key', function(err, val) {});
storage(['key', 'key2'], function(err, all) {}); // all.length == 2

// delete
storage('key', null, function(err) {});
storage(['key1', 'key2', 'key3'], null, function(err) {});

Get key value.

Get group of values. Callbacks return array of values for each key. If key does not exist, it returns undefined for this position.

Set key to val. You can store any kind of data, including blobs.

Delete key. Null semantic is inspired by yields/store and component/cookie. Setting a key to null is equivalent to deleting the key via storage.del(key).

Run a batch operation. Simple way to create, update, remove multiple records.

// assume we have 2 records
storage('foo', 7, fn)
storage('bar', ['one', 'two', 'three'], fn);

storage({
  baz: 'val' // create new val
  foo: 1000, // update `foo` value
  bar: null, // remove `bar`
}, function(err) {});

Delete a group of keys in one request.

It gives you access to the localForage instance. You can use it to configure backend.

storage.forage.config({ name: 'my-name' });
if (!window.indexedDB) storage.forage.setDriver('localStorageWrapper');

Clear storage.

Get the number of records in storage.

If you prefer more explicit API, you can use exposed functions.

storage.set('key', 'val', function(err) {});
storage.get('key', function(err, val) {}); // val
storage.del('key', function(err) {});

If you don't like callbacks, you can combine storage with then/promise.

var Promise = require('promise');
var orignal = require('storage');
var storage = Promise.denodeify(orignal);

storage('key').then(function(val) {});

Aleksey Kulikov, MIT.