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Problem: You need to store a large amount of key-value based data in IE, Chrome, Safari, AND Firefox
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dist Created min version Dec 10, 2013
examples/album Album uses its own db Oct 17, 2013
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bower.json Includes .min version Oct 21, 2013


Problem: You need a large key-value store in the browser.

To make things worse:

  • DOMStorage only gives you 5mb
  • Chrome doesn't let you store blobs in IndexedDB
  • Safari doesn't support IndexedDB,
  • IE and Firefox both support IndexedDB but not the FilesystemAPI.

LargeLocalStorage bridges all of that to give you a large capacity (up to several GB when authorized by the user) key-value store in the browser (IE 10, Chrome, Safari 6+, Firefox, Opera).

Basic Rundown / Examples

Creating a database

// Specify desired capacity in bytes
var desiredCapacity = 125 * 1024 * 1024;

// Create a 125MB key-value store
var storage = new LargeLocalStorage({size: desiredCapacity, name: 'myDb'});

// Await initialization of the storage area
storage.initialized.then(function(grantedCapacity) {
  // Check to see how much space the user authorized us to actually use.
  // Some browsers don't indicate how much space was granted in which case
  // grantedCapacity will be 1.
  if (grantedCapacity != -1 && grantedCapacity != desiredCapacity) {

Setting data

// You can set the contents of "documents" which are identified by a key.
// Documents can only contains strings for their values but binary
// data can be added as attachments.
// All operations are asynchronous and return Q promises
storage.setContents('docKey', "the contents...").then(function() {
  alert('doc created/updated');
// Attachments can be added to documents.
// Attachments are Blobs or any subclass of Blob (e.g, File).
// Attachments can be added whether or not a corresponding document exists.
// setAttachment returns a promise so you know when the set has completed.
storage.setAttachment('myDoc', 'titleImage', blob).then(function() {
    alert('finished setting the titleImage attachment');

Retrieving Data

// get the contents of a document
storage.getContents('myDoc').then(function(content) {

// Call getAttachment with the docKey and attachmentKey
storage.getAttachment('myDoc', 'titleImage').then(function(titleImage) {
    // Create an image element with the retrieved attachment
    // (or video or sound or whatever you decide to attach and use)
    var img = new Image();
    img.src = URL.createObjectURL(titleImage);

// If you just need a URL to your attachment you can get
// the attachment URL instead of the attachment itself
storge.getAttachmentURL('somePreviouslySavedDoc', 'someAttachment').then(function(url) {
  // do something with the attachment URL
  // ...
  // revoke the URL


// You can do an ls to get all of the keys in your data store {
  // listing is a list of all of the document keys
// Or get a listing of a document's attachments'somePreviouslySavedDoc').then(function(listing) {
  // listing is a list of all attachments belonging to `somePreviouslySavedDoc`


// you can remove a document with rm
// removing a document also removes all of that document's
// attachments.
// you can also rm an attachment
storage.rmAttachment('someOtherDocKey', 'attachmentKey');

// removals return promises as well so you know when the removal completes (or fails).
storage.rm('docKey').then(function() {
}, function(err) {
  console.error('Failed removal');

// clear the entire database



Include it on your page with a script tag:

<script src="path/to/LargeLocalStorage.js"></script>

Or load it as an amd module:

define(['components/lls/dist/LargeLocalStorage'], function(lls) {
  var storage = new lls({size: 100 * 1024 * 1024});

LLS depends on Q so you'll have to make sure you have that dependency.

##Getting downlad it directly

Or bower install lls

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