node-redis-eventbus

A simple event bus powered by redis to communicate between multiple node instances.

Install

``bash
npm install --save node-redis-eventbus

//or

yarn add node-redis-eventbus
`

Usage

Async/await pattern

`typescript
//Wrap example by an async function
(async () => {
//Create new event bus instance with a unique identifier
const eventBus = await EventBus.create('myEventBus');

//Add listener and wait until it's binded successfully
await eventBus.on('msg', (payload) => {
console.log(Received message: ${payload});

eventBus.destory();

process.exit();
});

console.log('Listening to msg event');

setTimeout(() => {
//Emit event to all listeners on the 'msg' event
eventBus.emit('msg', 'Hello');
}, 5000);
})();

//Somewhere else in your code get reference to the event bus
const eventBus = EventBus.getByName('myEventBus');
eventBus.emit('msg', 'Hello?');
`

Promise style


`typescript
//Create new event bus instance with a unique identifier
EventBus.create('myEventBus').then((eventBus) => {
//Add listener and wait until it's binded successfully
eventBus.on('msg', (payload) => {
console.log(Received message: ${payload});

eventBus.destory();

process.exit();
}).then(() => {
console.log('Listening to msg event');

setTimeout(() => {
eventBus.emit('msg', 'Hello');
}, 5000);
})
})

//Somewhere else in your code get reference to the event bus
const eventBus = EventBus.getByName('myEventBus');
eventBus.emit('msg', 'Hello?');
`

Docs


`typescript
//Register listener for specific event. To avoid sideeffects, you have to wait for the promise to resolve
on(event: string, callback: (payload: T) => void): Promise;

//Emit event on the event bus with passed payload
emit(event: string, payload: T): void;

//Sends ping to all listeners and waits maximum milliseconds
//Returns true if at least clients responded, false otherwise
ping(timeout?: number, minResponseCount?: number): Promise;

//Destroy this event bus instance and disconnect from redis
//Watch out: If there are other clients connected, these instances will not be destroyed!
destory(): void;

//Property which indicated wether the event bus is connected
connected: boolean;

//Creates a new event bus with a unique name and optional node-redis client options
static create(name: string, clientOpts?: Redis.ClientOpts): Promise;

//Access existing event bus instance by unique name
static getByName(name: string): EventBus;
`

Typescript


This package automatically ships a d.ts` definition file!