localstorage-down

A Node.js and browserify leveldown API implementation that maps to localstorage in the browser

Usage no npm install needed!

<script type="module">
  import localstorageDown from 'https://cdn.skypack.dev/localstorage-down';
</script>

README

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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):

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