Middlewares

Middlewares are executed before the request is passed to the method handler. They can be used to perform authentication, logging, etc.

Creating a middleware

A middleware class implements the Middleware class and must implement the handle method. The handle method receives the request object and transforms it into a response or a new request object.

Sending a response from a middleware will stop the execution of the request and return the response to the client while sending a new request object will continue the execution of the request with the modified request object.

Note: To use a middleware as an Annotation, the middleware must have a const constructor.

class Auth implements Middleware{
   const Auth();
   @override
   FutureOr<RequestOrResponse> handle(Request request) async {
      if(request.headers['Authorization'] == null){
         return RequestOrResponse(response: Response.unauthorized());
      }
      return RequestOrResponse(request: request);
   }
}

Using a middleware

To use a middleware, add it to the @Middleware annotation of the method handler.

class MyController extends Controller{
   ...
   
   @Path('/hello')
   @Auth()
   Future<Response> get() async {
      return Response.ok('Hello World');
   }
}