Github url

localForage

by localForage

localForage /localForage

💾 Offline storage, improved. Wraps IndexedDB, WebSQL, or localStorage using a simple but powerful A...

17.4K Stars 1.0K Forks Last release: about 1 month ago (1.7.4) Apache License 2.0 1.1K Commits 58 Releases

Available items

No Items, yet!

The developer of this repository has not created any items for sale yet. Need a bug fixed? Help with integration? A different license? Create a request here:

localForage

Build StatusNPM versionDependency StatusnpmjsDelivr Hitsminzipped size

localForage is a fast and simple storage library for JavaScript. localForage improves the offline experience of your web app by using asynchronous storage (IndexedDB or WebSQL) with a simple,

localStorage

-like API.

localForage uses localStorage in browsers with no IndexedDB or WebSQL support. See the wiki for detailed compatibility info.

To use localForage, just drop a single JavaScript file into your page:

<script src="localforage/dist/localforage.js"></script><script>localforage.getItem('something', myCallback);</script>

Try the live example.

Download the latest localForage from GitHub, or install withnpm:

npm install localforage

Support

Lost? Need help? Try thelocalForage API documentation. localForage API文档也有中文版。

If you're having trouble using the library, running the tests, or want to contribute to localForage, please look through the existing issues for your problem first before creating a new one. If you still need help, feel free to file an issue.

How to use localForage

Callbacks vs Promises

Because localForage uses async storage, it has an async API. It's otherwise exactly the same as thelocalStorage API.

localForage has a dual API that allows you to either use Node-style callbacks or Promises. If you are unsure which one is right for you, it's recommended to use Promises.

Here's an example of the Node-style callback form:

localforage.setItem('key', 'value', function (err) { // if err is non-null, we got an error localforage.getItem('key', function (err, value) { // if err is non-null, we got an error. otherwise, value is the value }); });

And the Promise form:

localforage.setItem('key', 'value').then(function () { return localforage.getItem('key'); }).then(function (value) { // we got our value }).catch(function (err) { // we got an error });

Or, use

async

/

await

:

try { const value = await localforage.getItem('somekey'); // This code runs once the value has been loaded // from the offline store. console.log(value); } catch (err) { // This code runs if there were any errors. console.log(err); }

For more examples, please visit the API docs.

Storing Blobs, TypedArrays, and other JS objects

You can store any type in localForage; you aren't limited to strings like in localStorage. Even if localStorage is your storage backend, localForage automatically does

JSON.parse()

and

JSON.stringify()

when getting/setting values.

localForage supports storing all native JS objects that can be serialized to JSON, as well as ArrayBuffers, Blobs, and TypedArrays. Check theAPI docs for a full list of types supported by localForage.

All types are supported in every storage backend, though storage limits in localStorage make storing many large Blobs impossible.

Configuration

You can set database information with the

config()

method. Available options are

driver

,

name

,

storeName

,

version

,

size

, and

description

.

Example:

javascript localforage.config({ driver : localforage.WEBSQL, // Force WebSQL; same as using setDriver() name : 'myApp', version : 1.0, size : 4980736, // Size of database, in bytes. WebSQL-only for now. storeName : 'keyvaluepairs', // Should be alphanumeric, with underscores. description : 'some description' });

Note: you must call

config()

before you interact with your data. This means calling

config()

before using

getItem()

,

setItem()

,

removeItem()

,

clear()

,

key()

,

keys()

or

length()

.

Multiple instances

You can create multiple instances of localForage that point to different stores using

createInstance

. All the configuration options used by[

config

](https://github.com/localForage/localForage/blob/master/#configuration) are supported.

var store = localforage.createInstance({ name: "nameHere" }); var otherStore = localforage.createInstance({ name: "otherName" }); // Setting the key on one of these doesn't affect the other. store.setItem("key", "value"); otherStore.setItem("key", "value2");

RequireJS

You can use localForage with RequireJS:

define(['localforage'], function(localforage) { // As a callback: localforage.setItem('mykey', 'myvalue', console.log); // With a Promise: localforage.setItem('mykey', 'myvalue').then(console.log); });

TypeScript

If you have the [

allowSyntheticDefaultImports

compiler option](https://www.typescriptlang.org/docs/handbook/compiler-options.html) set to

true

in your tsconfig.json (supported in TypeScript v1.8+), you should use:

import localForage from "localforage";

Otherwise you should use one of the following:

import \* as localForage from "localforage"; // or, in case that the typescript version that you are using // doesn't support ES6 style imports for UMD modules like localForage import localForage = require("localforage");

Framework Support

If you use a framework listed, there's a localForage storage driver for the models in your framework so you can store data offline with localForage. We have drivers for the following frameworks:

If you have a driver you'd like listed, pleaseopen an issue to have it added to this list.

Custom Drivers

You can create your own driver if you want; see the[

defineDriver

](https://localforage.github.io/localForage/#driver-api-definedriver) API docs.

There is a list of custom drivers on the wiki.

Working on localForage

You'll need node/npm andbower.

To work on localForage, you should start byforking it and installing its dependencies. Replace

USERNAME

with your GitHub username and run the following:

# Install bower globally if you don't have it: npm install -g bower # Replace USERNAME with your GitHub username: git clone [email protected]:USERNAME/localForage.git cd localForage npm install bower install

Omitting the bower dependencies will cause the tests to fail!

Running Tests

You need PhantomJS installed to run local tests. Run

npm test

(or, directly:

grunt test

). Your code must also pass thelinter.

localForage is designed to run in the browser, so the tests explicitly require a browser environment. Local tests are run on a headless WebKit (usingPhantomJS).

When you submit a pull request, tests will be run against all browsers that localForage supports on Travis CI using Sauce Labs.

Library Size

As of version 1.7.3 the payload added to your app is rather small. Served using gzip compression, localForage will add less than 10k to your total bundle size:

minified
`~29kB`
gzipped
`~8.8kB`
brotli'd
`~7.8kB`
# License

This program is free software; it is distributed under anApache License.


Copyright (c) 2013-2016 Mozilla(Contributors).

We use cookies. If you continue to browse the site, you agree to the use of cookies. For more information on our use of cookies please see our Privacy Policy.