express-beans

ExpressBeans

ExpressBeans is the IoC Container (Inversion of Control Container) that you didn't know you needed. If you love Node.js and the Spring Boot way of code organization this lightweight framework is for you. ExpressBeans is an almost zero dependency framework (it wraps Express.js) to offer an easy-to-use way of building your next Express project.

Get started

Try ExpressBeans with the official generator:

npm create express-beans-server

Documentation

API docs and types available in documentation.

Usage

All you need is create an ExpressBeans application and provide your RouterBean classes:

ExpressBeans.createApp({
  routerBeans: [
    ExampleRouter,
  ],
});

/* ======== OR ======== */

const application = new ExpressBeans({
  routerBeans: [
    ExampleRouter,
  ],
});

If you need also direct access to express application:

const application = new ExpressBeans({
  routerBeans: [
    ExampleRouter,
  ],
});
const expressApp = application.getApp();

Typescript 5

New decorators are here and ExpressBeans implements some simple decorators to achieve dependency injection and endpoint registration.

Example

import { Request, Response } from 'express';
import { InjectBean, Route, RouterBean } from 'express-beans';
import { ExampleService } from '../services/ExampleService';

@RouterBean('/example')
export class ExampleRouter {

  @InjectBean(ExampleService)
  private exampleService: ExampleService;

  @Route('GET', '/hello')
  getHello(_req: Request, res: Response) {
    res.end(this.exampleService.example());
  }
}

This will create a new router that expose an endpoint GET /example/hello and exampleService will be the instance of the class declared as it follow:

import { Bean } from 'express-beans';

@Bean
export class ExampleService {

  private msg: string;

  constructor() {
    this.msg = 'hello world!';
  }

  example() {
    return this.msg;
  }
}

Installation

npm install express-beans

Beans Lifecycle

The lifecycle of the beans is the following:

• start: The application starts, and tasks registered for this phase are executed.
• register: Beans and router beans are registered.
• routing: Routes are registered.
• init: The application is initialized, and tasks registered for this phase are executed.
• run: The application is running, and tasks registered for this phase are executed.
• exit: The application is shutting down, and tasks registered for this phase are executed.

Hooks

Setup

You can use the @Setup hook to add a function that will be executed right after the application is initialized.

@Setup
mySetupFunction() {
  // do something
}

Every request received will be served only after the application is initialized and @Setup functions are executed.

Shutdown

You can use the @Shutdown hook to add a function that will be executed right before the application is shutdown.

@Shutdown
myShutdownFunction() {
  // do something
}

Order

You can use the @Order hook to set the execution order of a hook. The default order is 0, negative orders are executed before positive ones in the same phase.

@Order(1)
@Setup
secondExecution() {
  // do something
}
@Order(-1)
@Setup
firstExecution() {
  // do something
}

Springboot like annotations

If you want to use Springboot like annotations you can use the following aliases:

• @PostConstruct -> @Setup
• @PreDestroy -> @Shutdown
• @Component -> @Bean
• @Service -> @Bean
• @Controller -> @RouterBean
• @Mapping -> @Route
• @Autowired -> @InjectBean

Contribute

Pull requests or issues/feature requests are welcome!

License

MIT