Shelf Interoperability

Shelf is a low-level web server library for Dart. It allows you to handle HTTP requests and responses directly. Shelf is also the most popular web server library for Dart and has a large ecosystem of plugins and middleware ready to use.

For this particular reason and to make Serinus more flexible, we have decided to make Serinus compatible with Shelf. This means that you can use Shelf plugins and middleware in your Serinus applications.

Usage

To use the Shelf Middlewares or Handlers in your Serinus application, you can use the Middleware class. The class has a factory constructor called Middleware.shelf that takes a shelf.Middleware or a shelf.Handler and returns a Serinus Middleware that can be used in your application.

The Middleware.shelf factory constructor allows also to pass a routes parameter that is a list of routes where the middleware will be applied.

Example

import 'package:serinus/serinus.dart';

import 'package:shelf/shelf.dart' as shelf;

final handler = (req) => shelf.Response.ok('Hello world from shelf');

class AppModule extends Module {
  AppModule() : super(
    imports: [],
    controllers: [],
    providers: [],
    middlewares: [
      Middleware.shelf(handler)
    ]
  );
}

In the example above, we are using a Shelf Handler to return a simple response. We are wrapping the Shelf Handler with the Middleware.shelf factory constructor to create a Serinus Middleware that can be used in the application.

You can pass to Middleware.shelf the following parameters:

Parameter	Description	Default
handler	The Shelf Middleware or Handler that will be used in the Serinus Middleware.	REQUIRED
routes	The list of routes where the middleware will be applied.	[*]
ignoreResponse	To ignore the response of the handler or not (If false and the handler return a response then the request lifecycle will be interrupted)	true

Conclusion

Thanks to the interoperability you can now use existing Shelf plugins and middleware in your Serinus applications increasing the capabilities of them to a new level.