Route Event Hooks

RoutingServiceProvider emits a series of events around every request. The example under examples/route_events/ prints them to stdout so you can see the order and payloads.

The event manager is registered by RoutingServiceProvider. Include that typed provider when composing a slim engine; Engine.create() with the normal defaults includes it already.

Available events

• BeforeRoutingEvent – fired before route matching begins.
• RouteMatchedEvent – the request matched a route (includes the EngineRoute).
• RouteNotFoundEvent – nothing matched; typically results in a 404.
• RoutingErrorEvent – a handler threw; inspect the error and stackTrace.
• AfterRoutingEvent – always fired after routing (even on errors) with the final response status.

Example

examples/route_events/bin/server.dart

import 'package:routed/routed.dart';
import 'package:routed/routed.dart';

Future<void> main(List<String> args) async {
  final engine = await Engine.create(providers: Engine.defaultProviders);

  final events = await engine.make<EventManager>();

  events.listen((BeforeRoutingEvent event) {
    print('[before] ${event.context.request.method} ${event.context.request.uri}');
  });

  events.listen((RouteMatchedEvent event) {
    print('[matched] ${event.route.name ?? '-'}');
  });

  events.listen((RouteNotFoundEvent event) {
    print('[not-found] ${event.context.request.path}');
  });

  events.listen((RoutingErrorEvent event) {
    print('[error] ${event.error}');
  });

  events.listen((AfterRoutingEvent event) {
    print('[after] status ${event.context.response.statusCode}');
  });

  engine.get('/', (ctx) => ctx.string('hello')).name('home');
  engine.get('/boom', (ctx) => throw StateError('Boom!'));

  await engine.serve(host: '127.0.0.1', port: 8081);
}

Run it and hit:

GET /        # triggers before/matched/after
GET /boom    # triggers before/matched/error/after
GET /missing # triggers before/not-found/after

Because these events are normal Dart streams you can attach logging, instrumentation, tracing, or metrics collectors without modifying your handlers.