duet-localforage

Use localForage with duet by selectively reading and writing asynchronously across threads when IndexedDB is not available to the worker, otherwise use it directly.

$ npm install duet-localforage

Usage

var duet        = require('duet');
var channel     = require('duet-localforage/channel');
var localforage = require('duet-localforage');
var logger      = console.log.bind(console);

duet([channel], function () {

    /* A: Promises */

    localforage.clear().then(logger);
    // >
    localforage.length().then(logger);
    // > 0
    localforage.setItem('foo', 'bar').then(logger);
    // > 'bar'
    localforage.key(0).then(logger);
    // > 'foo'
    localforage.keys().then(logger);
    // > ['foo']
    localforage.getItem('foo').then(logger);
    // > 'bar'
    localforage.iterator(logger).then(logger);
    // > 'bar', 'foo', 1
    // >
    localforage.removeItem('foo').then(logger);
    // >

    /* B: Callbacks */

    localforage.clear(logger);
    // > null
    localforage.length(logger);
    // > null, 0
    localforage.setItem('foo', 'bar', logger);
    // > null, 'bar'
    localforage.key(0, logger);
    // > null, 'foo'
    localforage.keys(logger);
    // > null, ['foo']
    localforage.getItem('foo', logger);
    // > null, 'bar'
    localforage.iterator(logger, logger);
    // > 'bar', 'foo', 1
    // > null
    localforage.removeItem('foo', logger);
    // > null
});

API

Everything is as you would expect on the localForage's callback and Promise-based async APIs.

Supported types

duet-localforage can safely store the following types of data:

• All† primitives
• Object
• Boolean object
• String object
• Blob
• Array
• ArrayBuffer
• Int8Array
• Uint8Array
• Uint8ClampedArray
• Int16Array
• Uint16Array
• Int32Array
• Uint32Array
• Float32Array
• Float64Array

This list is the intersection of the types that localForage can normally store, and the types that can be sent between workers as structured clones.

† Note about primitives: Symbol isn't supported. undefined will be stored and retrieved as null.