Decorators for Express

This library provides a set of TypeScript decorators to simplify route handling and dependency injection in Express applications. It includes route decorators like GetMapping, PostMapping, and ExpressController to streamline route registration, as well as Autowire and AutowireComponent for managing components and automatic dependency injection, enabling a clean, modular, and declarative approach to building Express-based applications.

ExpressMapping

The main decorator that handles binding a route to a controller method. It takes a path and an HTTP method (GET, POST, PUT, DELETE, USE) and registers the corresponding route in the Express application.

GetMapping, PostMapping, PutMapping, DeleteMapping, UseMapping Specialized decorators that call ExpressMapping with a specific HTTP method.

Decorators for Managing Controllers and Components

ExpressController: A decorator that registers a controller class to be used in your Express application.

AutowireComponent: A decorator for registering a class as a component that can be automatically injected into other parts of the application.

Autowire: A decorator for automatically injecting dependencies into the fields of other classes.

@ExpressController

Class decorator for express controllers

@ExpressController
export class SampleController {}

on import automatically creates instance and registers it.

@ExpressMapping

Creates method decorator that registers method in express app.

@ExpressMapping('/api/sample', 'get')
emptyObjectGet(req: Request, res: Response) {
  res.setHeader('Content-Type', 'application/json');
  res.send({});
}

@GetMapping

Uses ExpressMapping with predefined request method "get"

@GetMapping('/api/sample')
emptyObjectGet(req: Request, res: Response) {
  res.setHeader('Content-Type', 'application/json');
  res.send({});
}

@PostMapping

Uses ExpressMapping with predefined request method "post"

@PutMapping

Uses ExpressMapping with predefined request method "put"

@DeleteMapping

Uses ExpressMapping with predefined request method "delete"

@UseMapping

Uses ExpressMapping with predefined request method "use"

@AutowireComponent

Class decorator for autowire components

@AutowireComponent
export class SampleService implements SampleServiceInterface {}

on import automatically creates instance and registers it.

@Autowire

Field decorator that set's instance of registered AutowireComponent

@Autowire("SampleService")
sampleService: SampleServiceInterface;

Usage

First create and register Express app so decorators can work with it.

const app: Express = express();
registerExpressApp(app);

then import AutowireComponent's

then import ExpressController's

It's important to keep order of imports.

Import AutowireComponent first and then import component that uses it with Autowire decorator.