@art-of-coding/global-events

Global Events

Global Events is a node.js library which provides cross-process events by utilizing Redis' publish/subscribe mechanism. Events can be sent from any process, and all subscribed listeners will receive the event and its optional payload.

Global Events is built on top of (or rather, into) node's native EventEmitter, making it easy and familiar to use.

Features

• Send cross-process events the same way as you would locally
• Attach arbitrary data payloads to events
  • Data payloads are serialized by msgpackr for lightning-fast, light-weight payloads

Install

npm i @art-of-coding/global-events

Example

import IORedis from "ioredis";
import GlobalEvents from "@art-of-coding/global-events";

// Create a non-dedicated connection
// You can use this connection elsewhere
const connection = new IORedis();

const events = new GlobalEvents({
  // Set the Redis connection
  // This connection is duplicated internally to act as subscriber
  connection,
  // An optional prefix
  prefix: "prefix:",
  // Optional msgpackr configuration
  // See https://github.com/kriszyp/msgpackr#options
  msgpackr: { useRecords: true },
});

// Listen for an event
// Will automatically subscribe to the event if no subscription is open yet
events.on("expected-event", (data: MyDataInterface) => {
  // `data` is the event data if the event had a data payload
});

// Emit an event
events.emit("some-event");

// Emit an async event
await events.emitAsync("async-event");

// Emit an event with some data
events.emit("another-event", { some: "data" });

// Disconnect the subscriber
// After calling this the instance is no longer usable
await events.disconnect();

License

Copyright 2021 Michiel van der Velde.

This software is licensed under the MIT License.