Routing

When your application receives a request, it calls a controller method to generate the response. The routing configuration defines which action to run for each incoming URL.

Defining Routes

Routes can be defined by adding the @Route decorator to a controller method. Due to the way decorators work in TypeScript, you must also add the controller class to the controllers array in config/app.ts.

// src/controller/HomeController.ts
import {type IScope, Route} from '@koala-ts/framework';

export class HomeController {
  @Route({method: 'GET', path: '/'})
  index(scope: IScope): void {
    scope.response.body = {ok: true};
  }
}

// src/config/app.ts
import {type IKoalaConfig} from '@koala-ts/framework';
import {HomeController} from '../controller/HomeController';

export const appConfig: IKoalaConfig = {
  controllers: [HomeController],
};

In the example above, the index method of HomeController will be called when the application receives a GET request to /.

Matching HTTP Methods

The method property of the @Route decorator can be used to match specific HTTP methods. The value can be one of the following methods: GET, POST, PUT, PATCH, DELETE, OPTIONS, or HEAD.

You can also match multiple HTTP methods by passing an array of methods to the method property.

@Route({method: 'GET', path: '/'})
@Route({method: ['GET', 'POST'], path: '/'})

And to match all HTTP methods, you can use the ALL or ANY method.

@Route({method: 'ALL', path: '/'})
@Route({method: 'ANY', path: '/'})

Route Parameters

You can define route parameters by adding a colon : followed by the parameter name in the path property of the @Route decorator.

@Route({method: 'GET', path: '/user/:id'})

Then you can access the parameter value in the controller method by using scope.params.

const {id} = scope.params;

Middleware

You can add multiple middleware functions to a route by passing an array of middleware functions to the middleware property of the @Route decorator.

// src/controller/HomeController.ts
export class HomeController {
  @Route({method: 'GET', path: '/', middleware: [exampleMiddleware]})
  index(scope: IScope): void {
    scope.response.body = {ok: true};
  }
}

Below is an example of a middleware function.

// src/middleware/exampleMiddleware.ts
export async function exampleMiddleware(
  scope: IScope,
  next: INext,
): Promise<void> {
  console.log('Example middleware: Before controller');
  await next();
  console.log('Example middleware: After controller');
}