express-controller-class

Exposes @get, @post, @put, @patch and @delete method decorators and @controller class decorator to mark up classes as Express route handlers.

Also exposes @middleware method decorators to export methods as Express middleware - decorate a static method to export app-level middleware, or an instance method to register middleware for any route in that controller.

By themselves, the decorators just register route metadata for later use - to expose your controllers to an app, call the exposed util function initAppControllers with an existing express app and a list of controller classes (see example below).

The util will create singleton instances of each controller, create an Express Router for each distinct route those controllers define, and register its decorated methods as handlers on the router. The util then calls app.use() with each of those Routers before returning the initialized app.

Controller classes are instantiated by the util and should not expose a constructor that requires parameters. Any properties on a controller class must be initialized with a default value, or initAppControllers will error.

Why?

There's already a few of these libs out there, but all have strong opinions re: architecture or code style.

This lib just gives you exactly what you want - minimally-intrusive Express route controllers. The rest is up to you!

Example usage

import { controller, get, post } from 'express-controller-class';

@controller()
export class UserController {
  static route: '/users' // Base route for this controller.

  @middleware()
  static checkSession(request, response, next) {
    // App-level middleware - runs on every app request. `this` is the UserController class
  }

  @middleware()
  async checkPermissions(request, response, next) {
    // Controller-level middleware - runs on any route defined in this class
    // For example, to check whether the requester has permission to view or update other users
  }

  @get()
  async getAll(request: express.Request, response: express.Response) {
    // GET /users
    // Express route handler params are the same as they always are
  }

  @get('/:userId')
  async getOne(request, response) {
    // GET /users/123
    // Params are in the same place, `request.params`
  }

  @post('/:userId')
  async update(request, response) {
    // POST /users/123
    // Request data is where it always is, `request.body`
  }
}

import { initAppControllers } from 'express-controller-class';
import { UserController } from './user-controller';

const app = express();

initAppControllers(app,
[
  UserController
]);