nest-event

Nest Event

Event handler for Nest.js framework with decorators

Features

• Communicate between modules without import
• Organize event handlers with decorators
• Work with multiple Event Emitters

Installation

$ npm i --save nest-event

Usage

Import NestEventModule into your root module (AppModule)

// app.module.ts

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { NestEventModule } from 'nest-event';
@Module({
  imports: [NestEventModule],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

Nest Event is coming with an internal event emitter. If you provide one without a name, the module do not create the internal emitter. Also, you can use any instance with extended from EventEmitter

To provide an emitter use @Emitter decorator.

import { EventEmitter } from 'events';
import { Injectable } from '@nestjs/common';
import { Emitter } from './nest-event';

@Emitter()
export class MyEventEmitter extends EventEmitter {}

You can provide multiple emitters with passing a name.

@Emitter('ws-emitter')
export class WebsocketClient extends Websocket {}

Event Handler

To adding a listener for an event you can use @On decorator.

import { Injectable } from '@nestjs/common';
import { On } from './nest-event';
import { User } from './interfaces';

@Injectable()
export class EmailService {

  @On('user-created')
  onUserCreated(user: User){
    // send verification email
  }
}