feathers-lowdb

feathers-lowdb is a database service adapter for Lowdb, a small JSON database for Node, Electron and the browser powered by Lodash. LowDB can store data in-memory or on the filesystem which makes it useful as a persistent storage without a separate database server.

$ npm i --save lowdb feathers-lowdb

Important: feathers-lowdb implements the Feathers Common database adapter API and querying syntax.

API

service(options)

Returns a new service instance initialized with the given options. Model has to be an LowDB database instance.

const low = require('lowdb');
const FileSync = require('lowdb/adapters/FileSync');
const service = require('feathers-lowdb');

const adapter = new FileSync('./data/messages.json');
// Create a LowDB instance
const Model = low(adapter);

app.use('/messages', service({ Model }));
app.use('/messages', service({ Model, id, events, paginate }));

Options:

• Model (required) - The LowDB database instance. See the LowDB API for more information.
• id (optional, default: '_id') - The name of the id field property.
• events (optional) - A list of custom service events sent by this service
• paginate (optional) - A pagination object containing a default and max page size
• multi (optional) - Allow create with arrays and update and remove with id null to change multiple items. Can be true for all methods or an array of multi methods (e.g. [ 'remove', 'create' ])

Example

Here is an example of a Feathers server with a messages LowDB service that supports pagination and persists to db-data/messages:

$ npm i --save @feathersjs/feathers @feathersjs/errors @feathersjs/express @feathersjs/socketio feathers-lowdb lowdb

In app.js:

const feathers = require('@feathersjs/feathers');
const express = require('@feathersjs/express');
const socketio = require('@feathersjs/socketio');

const low = require('lowdb');
const FileSync = require('lowdb/adapters/FileSync');
const service = require('feathers-lowdb');

const adapter = new FileSync('./data/messages.json');
// Create a LowDB instance
const db = low(adapter);

// Create an Express compatible Feathers application instance.
const app = express(feathers());
// Turn on JSON parser for REST services
app.use(express.json());
// Turn on URL-encoded parser for REST services
app.use(express.urlencoded({ extended: true }));
// Enable REST services
app.configure(express.rest());
// Enable Socket.io services
app.configure(socketio());
// Connect to the db, create and register a Feathers service.
app.use(
  '/messages',
  service({
    Model: db,
    paginate: {
      default: 2,
      max: 4,
    },
  }),
);
// Set up default error handler
app.use(express.errorHandler());

// Create a dummy Message
app
  .service('messages')
  .create({
    text: 'Message created on server',
  })
  .then((message) => console.log('Created message', message));

// Start the server.
const port = 3030;

app.listen(port, () => {
  console.log(`Feathers server listening on port ${port}`);
});

Run the example with node app and go to localhost:3030/messages.

License

Copyright (c) 2019

Licensed under the MIT license.