Package Exports

@node-ts/bus-core
@node-ts/bus-core/dist/bus-symbols
@node-ts/bus-core/dist/service-bus
@node-ts/bus-core/dist/transport
@node-ts/bus-core/dist/util/class-constructor

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@node-ts/bus-core) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

@node-ts/bus-core

The core messaging framework. This package provides an in-memory queue and persistence by default, but is designed to be used with other @node-ts/bus-* packages that provide compatibility with other transports (SQS, RabbitMQ, Azure Queues) and persistence technologies (PostgreSQL, SQL Server, Oracle).

Installation

Download and install the packages:

npm i inversify @node-ts/bus-core --save

Load BusModule into your application's inversify container:

// application-container.ts

import { Container } from 'inversify'
import { BusModule } from '@node-ts/bus-core'

export class ApplicationContainer extends Container {
  constructor () {
    this.load(new BusModule())
  }
}

Register a message handler

Messages are handled by defining and registring a handler class. Each time a message is received by the application, it will be dispatched to each of the registered handlers.

Define the handler:

// send-email-handler.ts

import { injectable } from 'inversify'
import { Handles, Handler } from '@node-ts/bus-core'
import { SendEmail } from 'my-corporation/commands'
import { SERVICE_SYMBOLS, EmailService } from '../services'

@Handles(SendEmail)
export class SendEmailHandler implements Handler<SendEmail> {
  
  constructor (
    @inject(SERVICE_SYMBOLS.EmailService) private readonly emailService: EmailService
  ) {
  }

  async handle (sendEmailCommand: SendEmail): Promise<void> {
    await this.emailService.send(
      sendEmailCommand.to,
      sendEmailCommand.title,
      sendEmailCommand.body
    )
  }
}

// application.ts

import { inject, injectable } from 'inversify'
import { BUS_SYMBOLS, ApplicationBootstrap, Bus } from '@node-ts/bus-core'

@injectable()
export class Application {

  constructor (
    @inject(BUS_SYMBOLS.ApplicationBootstrap) private readonly applicationBootstrap: ApplicationBootstrap,
    @inject(BUS_SYMBOLS.Bus) private readonly bus: Bus
  ) {
  }

  async initialize (): Promise<void> {
    this.applicationBootstrap.registerHandler(SendEmailHandler)

    // Starts the receive loop on the bus to pull messages from the queue and dispatch to handlers
    await this.applicationBootstrap.initialize()
  }

  async stop (): Promise<void> {
    // Stops the queue polling mechanism so the app shuts down cleanly
    await this.bus.stop()
  }
}