v5

lib/go_router/examples/others/nav_observer.dart

@@ -0,0 +1,167 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'package:logging/logging.dart';
+
+void main() => runApp(App());
+
+/// The main app.
+class App extends StatelessWidget {
+  /// Creates an [App].
+  App({super.key});
+
+  /// The title of the app.
+  static const String title = 'GoRouter Example: Navigator Observer';
+
+  @override
+  Widget build(BuildContext context) => MaterialApp.router(
+        routerConfig: _router,
+        title: title,
+      );
+
+  final GoRouter _router = GoRouter(
+    observers: <NavigatorObserver>[MyNavObserver()],
+    routes: <GoRoute>[
+      GoRoute(
+        // if there's no name, path will be used as name for observers
+        path: '/',
+        builder: (BuildContext context, GoRouterState state) =>
+            const Page1Screen(),
+        routes: <GoRoute>[
+          GoRoute(
+            name: 'page2',
+            path: 'page2/:p1',
+            builder: (BuildContext context, GoRouterState state) =>
+                const Page2Screen(),
+            routes: <GoRoute>[
+              GoRoute(
+                name: 'page3',
+                path: 'page3',
+                builder: (BuildContext context, GoRouterState state) =>
+                    const Page3Screen(),
+              ),
+            ],
+          ),
+        ],
+      ),
+    ],
+  );
+}
+
+/// The Navigator observer.
+class MyNavObserver extends NavigatorObserver {
+  /// Creates a [MyNavObserver].
+  MyNavObserver() {
+    log.onRecord.listen((LogRecord e) => debugPrint('$e'));
+  }
+
+  /// The logged message.
+  final Logger log = Logger('MyNavObserver');
+
+  @override
+  void didPush(Route<dynamic> route, Route<dynamic>? previousRoute) =>
+      log.info('didPush: ${route.str}, previousRoute= ${previousRoute?.str}');
+
+  @override
+  void didPop(Route<dynamic> route, Route<dynamic>? previousRoute) =>
+      log.info('didPop: ${route.str}, previousRoute= ${previousRoute?.str}');
+
+  @override
+  void didRemove(Route<dynamic> route, Route<dynamic>? previousRoute) =>
+      log.info('didRemove: ${route.str}, previousRoute= ${previousRoute?.str}');
+
+  @override
+  void didReplace({Route<dynamic>? newRoute, Route<dynamic>? oldRoute}) =>
+      log.info('didReplace: new= ${newRoute?.str}, old= ${oldRoute?.str}');
+
+  @override
+  void didStartUserGesture(
+    Route<dynamic> route,
+    Route<dynamic>? previousRoute,
+  ) =>
+      log.info('didStartUserGesture: ${route.str}, '
+          'previousRoute= ${previousRoute?.str}');
+
+  @override
+  void didStopUserGesture() => log.info('didStopUserGesture');
+}
+
+extension on Route<dynamic> {
+  String get str => 'route(${settings.name}: ${settings.arguments})';
+}
+
+/// The screen of the first page.
+class Page1Screen extends StatelessWidget {
+  /// Creates a [Page1Screen].
+  const Page1Screen({super.key});
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+        appBar: AppBar(title: const Text(App.title)),
+        body: Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              ElevatedButton(
+                onPressed: () => context.goNamed(
+                  'page2',
+                  pathParameters: <String, String>{'p1': 'pv1'},
+                  queryParameters: <String, String>{'q1': 'qv1'},
+                ),
+                child: const Text('Go to page 2'),
+              ),
+            ],
+          ),
+        ),
+      );
+}
+
+/// The screen of the second page.
+class Page2Screen extends StatelessWidget {
+  /// Creates a [Page2Screen].
+  const Page2Screen({super.key});
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+        appBar: AppBar(title: const Text(App.title)),
+        body: Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              ElevatedButton(
+                onPressed: () => context.goNamed(
+                  'page3',
+                  pathParameters: <String, String>{'p1': 'pv2'},
+                ),
+                child: const Text('Go to page 3'),
+              ),
+            ],
+          ),
+        ),
+      );
+}
+
+/// The screen of the third page.
+class Page3Screen extends StatelessWidget {
+  /// Creates a [Page3Screen].
+  const Page3Screen({super.key});
+
+  @override
+  Widget build(BuildContext context) => Scaffold(
+        appBar: AppBar(title: const Text(App.title)),
+        body: Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: <Widget>[
+              ElevatedButton(
+                onPressed: () => context.go('/'),
+                child: const Text('Go to home page'),
+              ),
+            ],
+          ),
+        ),
+      );
+}