localstorage-down

localstorage-down

LocalStorage implementation of leveldown for mobile and desktop browsers. The idea is to be able to use the level stack on any browser that supports LocalStorage.

The scenarios envisaged are:

1. Occasionally connected clients
2. Ad-hoc networks where clients need to sync directly with each other

This project is intended for use with the level eco-system.

Install

npm install localstorage-down

Browser support

Basically we support any browser that has LocalStorage, but since we also rely on an ES5 environment due to dependencies from abstract-leveldown, in practice you will need the following shims in order to work correctly on all browsers (e.g. IE 8-9, Android 2.3):

• typedarray for binary storage
• es5-shim for just about everything

We run automated tests in the following browsers:

• Firefox: 40-latest
• Chrome: 44-beta
• IE: 9-11
• Edge: latest
• Safari: 7.0-latest
• iPhone: 8.0-latest
• Android: 4.1-latest

In environments without LocalStorage, such as Node or Safari private browsing, this module will fall back to a temporary in-memory implementation, thanks to humble-localstorage.

Example

At the command prompt in your chosen directory :

npm install localstorage-down
npm install levelup 
npm install browserify -g
npm install beefy -g

Create a file called index.js and enter the following:

var localstorage = require('localstorage-down');
var levelup = require('levelup');
var db = levelup('dbname', { db: localstorage });

db.put('name', 'James Dean');
db.put('dob', 'February 8, 1931');
db.put('occupation', 'Rebel');
db.put('cause', 'none');

db.readStream()
   .on('data', function (data) {
      if (typeof data.value !== 'undefined') {
         console.log(data.key, '=', data.value);
      }
   })
   .on('error', function (err) {
      console.log('Oh my!', err);
   })
   .on('close', function () {
      console.log('Stream closed');
   })
   .on('end', function () {
     console.log('Stream ended');
   });

Publish the site :

beefy index.js

See the output :

http://localhost:9966

Listen to John Cage:

https://www.youtube.com/watch?v=9hVFCmK6GgM

Tests

npm run test

This will run tests in Node against localstorage-memory.

To test in Saucelabs, you can run e.g.:

npm run test-browser

Or to test in Zuul locally:

npm run test-zuul-local

To test and check code coverage, run:

npm run coverage

To test and report code coverage to Coveralls, run:

npm run report-coverage

Contributors

• Anton Whalley
• Adam Shih
• Nolan Lawson
• Many more!