Initial (redacted) commit.

learning/demo-app/lib/l10n/app_de.arb

@@ -0,0 +1,20 @@
+{
+  "@@locale": "de",
+  "appTitle": "Demo-App mit Riverpod und go_router",
+  "ok": "Ok",
+  "cancel": "Abbrechen",
+  "yes": "Ja",
+  "no": "Nein",
+  "add": "Hinzufügen",
+  "save": "Speichern",
+  "error": "Sorry, da ist etwas schief gegangen...",
+  "loading": "Lade ...",
+  "select": "Auswahl",
+  "selected": "Ausgewählt",
+  "search": "Suche",
+  "counterLabel": "Du hast den Button sooft gedrückt:",
+  "fabMainTooltip": "erhöhen",
+  "placeholder": "placeholder",
+  "home": "Start",
+  "counter": "Zähler"
+}

learning/demo-app/lib/l10n/app_en.arb

@@ -0,0 +1,27 @@
+{
+  "@@locale": "en",
+  "appTitle": "Demo app with riverpod and go_router",
+  "ok": "Ok",
+  "cancel": "Cancel",
+  "yes": "Yes",
+  "no": "No",
+  "add": "Add",
+  "save": "Save",
+  "error": "We apologize for the inconvenience. This should not have happened...",
+  "loading": "Loading",
+  "select": "Select",
+  "selected": "Selected",
+  "deselect": "Deselect",
+  "search": "Search",
+  "counterLabel": "You have pushed the button this many times:",
+  "fabMainTooltip": "Increment",
+  "placeholder": "placeholder",
+  "requiredField": "This field is required",
+  "labelName": "Name",
+  "labelImageUrl": "Url of an image",
+  "delete": "Delete",
+  "home": "Home",
+  "counter": "Counter",
+  "details": "Details",
+  "noItems": "Sorry, no items."
+}

learning/demo-app/lib/main.dart

@@ -0,0 +1,30 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'src/routing/app_router.dart';
+import 'src/utils/localization.dart';
+
+Future<void> main() async {
+  runApp(const ProviderScope(child: MyApp()));
+}
+
+class MyApp extends ConsumerWidget {
+  const MyApp({super.key});
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final goRouter = ref.watch(goRouterProvider);
+    return MaterialApp.router(
+      routerConfig: goRouter,
+      debugShowCheckedModeBanner: false,
+      onGenerateTitle: (context) => context.loc.appTitle,
+      theme: ThemeData(
+        colorScheme: ColorScheme.fromSeed(seedColor: Colors.green),
+        useMaterial3: true,
+      ),
+      localizationsDelegates: AppLocalizations.localizationsDelegates,
+      supportedLocales: AppLocalizations.supportedLocales,
+      // use to find missing semantics
+      // showSemanticsDebugger: true,
+    );
+  }
+}

learning/demo-app/lib/src/common_widgets/async_value_widget.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import 'error_message_widget.dart';
+
+//credits to  Code with Andrea https://github.com/bizz84/starter_architecture_flutter_firebase/blob/master/lib/src/common_widgets/async_value_widget.dart
+class AsyncValueWidget<T> extends StatelessWidget {
+  const AsyncValueWidget({required this.value, required this.data, super.key});
+  final AsyncValue<T> value;
+  final Widget Function(T) data;
+
+  @override
+  Widget build(BuildContext context) {
+    return value.when(
+      data: data,
+      error: (error, st) => Center(child: ErrorMessageWidget(error)),
+      loading: () => const SizedBox(
+        width: 60,
+        height: 60,
+        child: Center(child: CircularProgressIndicator()),
+      ),
+    );
+  }
+}

learning/demo-app/lib/src/common_widgets/error_message_widget.dart

@@ -0,0 +1,55 @@
+import 'package:dio/dio.dart';
+import 'package:flutter/material.dart';
+import 'package:ri_go_demo/src/exceptions/api_exception.dart';
+
+import '../utils/localization.dart';
+import '../utils/logger.dart';
+
+//credits to Code with Andrea https://github.com/bizz84/starter_architecture_flutter_firebase/blob/master/lib/src/common_widgets/error_message_widget.dart
+
+/// Simple reusable widget to show errors to the user.
+class ErrorMessageWidget extends StatelessWidget {
+  const ErrorMessageWidget(this.error, {super.key});
+
+  /// Error object, might be a DioException.
+  final Object? error;
+  @override
+  Widget build(BuildContext context) {
+    return Text(
+      _pimpError(error, context.loc.error),
+      style:
+          Theme.of(context).textTheme.titleLarge!.copyWith(color: Colors.red),
+    );
+  }
+
+  String _pimpError(Object? error, String defaultStr) {
+    if (error == null) {
+      logger.d('ErrorMessageWidget - _pimpError - no error');
+      return defaultStr;
+    }
+    try {
+      final dioEx = error as DioException;
+      if (dioEx.response != null) {
+        final map = dioEx.response!.data as Map<String, dynamic>;
+        if (map.containsKey('detail')) {
+          return map['detail']! as String;
+        }
+      }
+    } catch (ex) {
+      logger.e(
+        'ErrorMessageWidget - _pimpError - could not extract info',
+        error: ex,
+      );
+    }
+    try {
+      final apiException = error as ApiException;
+      return 'status ${apiException.statusCode}: ${apiException.message}';
+    } catch (ex) {
+      logger.e(
+        'ErrorMessageWidget - _pimpError - could not extract message',
+        error: ex,
+      );
+    }
+    return defaultStr;
+  }
+}

learning/demo-app/lib/src/common_widgets/form_field_widget.dart

@@ -0,0 +1,50 @@
+import 'package:flutter/material.dart';
+
+//similar from code with Andrea
+class FormFieldWidget extends StatelessWidget {
+  const FormFieldWidget({
+    required this.controller,
+    required this.labelText,
+    super.key,
+    this.keyboardType,
+    this.formFieldKey,
+    this.required = false,
+    this.initialValue = '',
+  });
+
+  final TextEditingController controller;
+  final String labelText;
+  final TextInputType? keyboardType;
+  final bool required;
+
+  final Key? formFieldKey;
+
+  final String initialValue;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        Semantics(
+          label: labelText,
+          child: TextFormField(
+            key: formFieldKey,
+            controller: controller,
+            decoration: InputDecoration(
+              labelText: labelText,
+            ),
+            autocorrect: false,
+            textInputAction: TextInputAction.next,
+            keyboardType: keyboardType,
+            validator: (value) {
+              if (required && (value == null || value.isEmpty)) {
+                return ''; //context.loc.requiredField;
+              }
+              return null;
+            },
+          ),
+        ),
+      ],
+    );
+  }
+}

learning/demo-app/lib/src/common_widgets/primary_button.dart

@@ -0,0 +1,45 @@
+import 'package:flutter/material.dart';
+
+// credits to Code with Andrea, https://github.com/bizz84/starter_architecture_flutter_firebase/blob/master/lib/src/common_widgets/primary_button.dart
+
+class PrimaryButton extends StatelessWidget {
+  const PrimaryButton({
+    required this.label,
+    required this.onPressed,
+    super.key,
+    this.isEnabled = true,
+    this.backgroundColor,
+    this.foregroundColor,
+  });
+  final VoidCallback? onPressed;
+  final String label;
+  final bool isEnabled;
+  final Color? backgroundColor;
+  final Color? foregroundColor;
+  @override
+  Widget build(BuildContext context) {
+    return Align(
+      alignment: Alignment.bottomCenter,
+      child: Padding(
+        padding: const EdgeInsets.all(12),
+        child: SizedBox(
+          height: 48,
+          child: ElevatedButton(
+            onPressed: isEnabled ? onPressed : null,
+            style: ElevatedButton.styleFrom(
+              backgroundColor:
+                  backgroundColor ?? Theme.of(context).colorScheme.primary,
+              foregroundColor:
+                  foregroundColor ?? Theme.of(context).colorScheme.onPrimary,
+            ),
+            child: Text(
+              label,
+              textAlign: TextAlign.center,
+              style: Theme.of(context).textTheme.titleLarge,
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}

learning/demo-app/lib/src/common_widgets/two_panel_widget.dart

@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+
+import '../constants/breakpoint.dart';
+
+class TwoPanelWidget extends StatelessWidget {
+  const TwoPanelWidget({
+    required this.firstPanel,
+    required this.secondPanel,
+    super.key,
+  });
+  final Widget firstPanel;
+  final Widget secondPanel;
+  @override
+  Widget build(BuildContext context) {
+    final screenSize = MediaQuery.of(context).size;
+    final isWideScreen = screenSize.width > Breakpoint.tablet;
+
+    if (isWideScreen) {
+      // Display master and detail side by side
+      return Row(
+        children: [
+          Expanded(
+            flex: 2,
+            child: firstPanel,
+          ),
+          Expanded(
+            flex: 2,
+            child: secondPanel,
+          ),
+        ],
+      );
+    } else {
+      // Display master and detail vertically
+      return Column(
+        children: [
+          Expanded(
+            flex: 2,
+            child: firstPanel,
+          ),
+          Expanded(
+            flex: 2,
+            child: secondPanel,
+          ),
+        ], // Display the first item initially
+      );
+    }
+  }
+}

learning/demo-app/lib/src/constants/api.dart

@@ -0,0 +1,6 @@
+// https://api-generator.retool.com/grQMFP/crud-demo/
+abstract class Api {
+  static const String schema = 'https';
+  static const String host = 'api-generator.retool.com';
+  static const String path = 'grQMFP/crud-demo/';
+}

learning/demo-app/lib/src/constants/breakpoint.dart

@@ -0,0 +1,3 @@
+class Breakpoint {
+  static const double tablet = 600;
+}

learning/demo-app/lib/src/constants/ui_constants.dart

@@ -0,0 +1,5 @@
+abstract class UIConstants {
+  static const double minHitTargetHeight = 55;
+  static const double verticalItemSpace = 8;
+  static const double defaultPadding = 12;
+}

learning/demo-app/lib/src/exceptions/api_exception.dart

@@ -0,0 +1,8 @@
+class ApiException implements Exception {
+  ApiException(this.statusCode, this.message);
+  final int statusCode;
+  final String message;
+
+  @override
+  String toString() => message;
+}

learning/demo-app/lib/src/features/counter/presentation/counter_screen.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import '../../../utils/localization.dart';
+import 'counter_screen_controller.dart';
+
+class CounterScreen extends ConsumerWidget {
+  const CounterScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final state = ref.watch(counterProvider);
+    final controller = ref.read(counterProvider.notifier);
+
+    return Scaffold(
+      appBar: AppBar(
+        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+        title: Text(context.loc.appTitle),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+            Text(
+              context.loc.counterLabel,
+            ),
+            Text(
+              '$state',
+              style: Theme.of(context).textTheme.headlineMedium,
+            ),
+          ],
+        ),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: controller.increment,
+        tooltip: context.loc.fabMainTooltip,
+        child: const Icon(Icons.add),
+      ),
+    );
+  }
+}

learning/demo-app/lib/src/features/counter/presentation/counter_screen_controller.dart

@@ -0,0 +1,25 @@
+
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'counter_screen_controller.g.dart';
+
+
+/// Annotating a class by `@riverpod` defines a new shared 
+/// state for your application,
+/// accessible using the generated [counterProvider].
+/// This class is both responsible for initializing the state (through the 
+/// [build] method)
+/// and exposing ways to modify it (cf [increment]).
+@riverpod
+class Counter extends _$Counter {
+  /// Classes annotated by `@riverpod` **must** define a [build] function.
+  /// This function is expected to return the initial state of your 
+  /// shared state.
+  /// It is totally acceptable for this function to return a [Future] or 
+  /// [Stream] if you need to.
+  /// You can also freely define parameters on this method.
+  @override
+  int build() => 0;
+
+  void increment() => state++;
+}

learning/demo-app/lib/src/features/counter/presentation/counter_screen_controller.g.dart

@@ -0,0 +1,30 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'counter_screen_controller.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$counterHash() => r'4243b34530f53accfd9014a9f0e316fe304ada3e';
+
+/// Annotating a class by `@riverpod` defines a new shared
+/// state for your application,
+/// accessible using the generated [counterProvider].
+/// This class is both responsible for initializing the state (through the
+/// [build] method)
+/// and exposing ways to modify it (cf [increment]).
+///
+/// Copied from [Counter].
+@ProviderFor(Counter)
+final counterProvider = AutoDisposeNotifierProvider<Counter, int>.internal(
+  Counter.new,
+  name: r'counterProvider',
+  debugGetCreateSourceHash:
+      const bool.fromEnvironment('dart.vm.product') ? null : _$counterHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef _$Counter = AutoDisposeNotifier<int>;
+// ignore_for_file: unnecessary_raw_strings, subtype_of_sealed_class, invalid_use_of_internal_member, do_not_use_environment, prefer_const_constructors, public_member_api_docs, avoid_private_typedef_functions

learning/demo-app/lib/src/features/rest_crud_demo/data/people_repository.dart

@@ -0,0 +1,124 @@
+import 'dart:convert';
+
+import 'package:dio/dio.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+import '../../../constants/api.dart';
+import '../../../exceptions/api_exception.dart';
+import '../../../utils/dio_provider.dart';
+import '../../../utils/logger.dart';
+import '../domain/person.dart';
+
+part 'people_repository.g.dart';
+
+class PeopleRepository {
+  PeopleRepository({required this.dio});
+  final Dio dio;
+
+  String _getUrl({int? id}) {
+    final url =
+        Uri(scheme: Api.schema, host: Api.host, path: Api.path).toString();
+    if (id != null) {
+      return '$url$id';
+    } else {
+      return url;
+    }
+  }
+
+  Future<Person> getPersonById({required int id}) async {
+    final url = _getUrl(id: id);
+    // ignore: inference_failure_on_function_invocation
+    final response = await dio.get<String>(url);
+    if (response.statusCode == 200 && response.data != null) {
+      final person =
+          Person.fromJson(json.decode(response.data!) as Map<String, Object?>);
+      return person;
+    } else {
+      throw ApiException(
+        response.statusCode ?? -1,
+        'getPersonById ${response.statusCode}, data=${response.data}',
+      );
+    }
+  }
+
+  Future<List<Person>> getPeople() async {
+    logger.d('people_repository.getPeople');
+    final url = _getUrl();
+    final response = await dio.get<List<dynamic>>(url);
+    if (response.statusCode == 200 && response.data != null) {
+      final dataList = response.data!;
+      return dataList
+          .map(
+            (personJson) => Person.fromJson(personJson as Map<String, Object?>),
+          )
+          .toList();
+    } else {
+      throw ApiException(
+        response.statusCode ?? -1,
+        'getPeople ${response.statusCode}, data=${response.data}',
+      );
+    }
+  }
+
+  Future<Person> updatePerson({required Person person}) async {
+    final url = _getUrl(id: person.id);
+    final response = await dio.put<String>(url, data: person.toJson());
+    if (response.statusCode == 200 && response.data != null) {
+      final personUpdated =
+          Person.fromJson(json.decode(response.data!) as Map<String, Object?>);
+      return personUpdated;
+    } else {
+      throw ApiException(
+        response.statusCode ?? -1,
+        'updateOwner ${response.statusCode}, data=${response.data}',
+      );
+    }
+  }
+
+  Future<bool> deletePerson(int id) async {
+    final url = _getUrl(id: id);
+    final response = await dio.delete<String>(url);
+    if (response.statusCode == 200) {
+      return true;
+    } else {
+      throw ApiException(
+        response.statusCode ?? -1,
+        'deletePerson ${response.statusCode}, data=${response.data}',
+      );
+    }
+  }
+
+  Future<Person> savePerson({required Person person}) async {
+    final url = _getUrl();
+    // this api uses the id if it exists, hence in case of a post
+    // we make sure, there is no id
+    final response =
+        await dio.post<String>(url, data: person.toJsonWithoutId());
+    if (response.statusCode == 201 && response.data != null) {
+      final newPerson =
+          Person.fromJson(json.decode(response.data!) as Map<String, Object?>);
+      return newPerson;
+    } else {
+      throw ApiException(
+        response.statusCode ?? -1,
+        'savePerson ${response.statusCode}, data=${response.data}',
+      );
+    }
+  }
+}
+
+@riverpod
+PeopleRepository peopleRepository(PeopleRepositoryRef ref) =>
+    PeopleRepository(dio: ref.read(dioProvider));
+
+@riverpod
+Future<List<Person>> fetchPeople(FetchPeopleRef ref) async {
+  logger.d('people_repository.fetchPeople');
+  final repo = ref.read(peopleRepositoryProvider);
+  return repo.getPeople();
+}
+
+@riverpod
+Future<Person> fetchPersonById(FetchPersonByIdRef ref, int id) async {
+  final repo = ref.read(peopleRepositoryProvider);
+  return repo.getPersonById(id: id);
+}

learning/demo-app/lib/src/features/rest_crud_demo/data/people_repository.g.dart

@@ -0,0 +1,141 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'people_repository.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$peopleRepositoryHash() => r'd0e91e6cbf45120cbcd670b6cc99fe71a9d76429';
+
+/// See also [peopleRepository].
+@ProviderFor(peopleRepository)
+final peopleRepositoryProvider = AutoDisposeProvider<PeopleRepository>.internal(
+  peopleRepository,
+  name: r'peopleRepositoryProvider',
+  debugGetCreateSourceHash: const bool.fromEnvironment('dart.vm.product')
+      ? null
+      : _$peopleRepositoryHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef PeopleRepositoryRef = AutoDisposeProviderRef<PeopleRepository>;
+String _$fetchPeopleHash() => r'772e01d6c483daa24de83820a021601fa93618e7';
+
+/// See also [fetchPeople].
+@ProviderFor(fetchPeople)
+final fetchPeopleProvider = AutoDisposeFutureProvider<List<Person>>.internal(
+  fetchPeople,
+  name: r'fetchPeopleProvider',
+  debugGetCreateSourceHash:
+      const bool.fromEnvironment('dart.vm.product') ? null : _$fetchPeopleHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef FetchPeopleRef = AutoDisposeFutureProviderRef<List<Person>>;
+String _$fetchPersonByIdHash() => r'ab1560261f3491819dc88719e855f1c9b973ed21';
+
+/// Copied from Dart SDK
+class _SystemHash {
+  _SystemHash._();
+
+  static int combine(int hash, int value) {
+    // ignore: parameter_assignments
+    hash = 0x1fffffff & (hash + value);
+    // ignore: parameter_assignments
+    hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+    return hash ^ (hash >> 6);
+  }
+
+  static int finish(int hash) {
+    // ignore: parameter_assignments
+    hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+    // ignore: parameter_assignments
+    hash = hash ^ (hash >> 11);
+    return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+  }
+}
+
+typedef FetchPersonByIdRef = AutoDisposeFutureProviderRef<Person>;
+
+/// See also [fetchPersonById].
+@ProviderFor(fetchPersonById)
+const fetchPersonByIdProvider = FetchPersonByIdFamily();
+
+/// See also [fetchPersonById].
+class FetchPersonByIdFamily extends Family<AsyncValue<Person>> {
+  /// See also [fetchPersonById].
+  const FetchPersonByIdFamily();
+
+  /// See also [fetchPersonById].
+  FetchPersonByIdProvider call(
+    int id,
+  ) {
+    return FetchPersonByIdProvider(
+      id,
+    );
+  }
+
+  @override
+  FetchPersonByIdProvider getProviderOverride(
+    covariant FetchPersonByIdProvider provider,
+  ) {
+    return call(
+      provider.id,
+    );
+  }
+
+  static const Iterable<ProviderOrFamily>? _dependencies = null;
+
+  @override
+  Iterable<ProviderOrFamily>? get dependencies => _dependencies;
+
+  static const Iterable<ProviderOrFamily>? _allTransitiveDependencies = null;
+
+  @override
+  Iterable<ProviderOrFamily>? get allTransitiveDependencies =>
+      _allTransitiveDependencies;
+
+  @override
+  String? get name => r'fetchPersonByIdProvider';
+}
+
+/// See also [fetchPersonById].
+class FetchPersonByIdProvider extends AutoDisposeFutureProvider<Person> {
+  /// See also [fetchPersonById].
+  FetchPersonByIdProvider(
+    this.id,
+  ) : super.internal(
+          (ref) => fetchPersonById(
+            ref,
+            id,
+          ),
+          from: fetchPersonByIdProvider,
+          name: r'fetchPersonByIdProvider',
+          debugGetCreateSourceHash:
+              const bool.fromEnvironment('dart.vm.product')
+                  ? null
+                  : _$fetchPersonByIdHash,
+          dependencies: FetchPersonByIdFamily._dependencies,
+          allTransitiveDependencies:
+              FetchPersonByIdFamily._allTransitiveDependencies,
+        );
+
+  final int id;
+
+  @override
+  bool operator ==(Object other) {
+    return other is FetchPersonByIdProvider && other.id == id;
+  }
+
+  @override
+  int get hashCode {
+    var hash = _SystemHash.combine(0, runtimeType.hashCode);
+    hash = _SystemHash.combine(hash, id.hashCode);
+
+    return _SystemHash.finish(hash);
+  }
+}
+// ignore_for_file: unnecessary_raw_strings, subtype_of_sealed_class, invalid_use_of_internal_member, do_not_use_environment, prefer_const_constructors, public_member_api_docs, avoid_private_typedef_functions

learning/demo-app/lib/src/features/rest_crud_demo/domain/person.dart

@@ -0,0 +1,37 @@
+import 'dart:convert';
+
+import 'package:flutter/foundation.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'person.freezed.dart';
+part 'person.g.dart';
+
+@freezed
+class Person with _$Person {
+  const factory Person({
+    required int id,
+    required String name,
+    required String imageUrl,
+  }) = _Person;
+
+  factory Person.fromJson(Map<String, Object?> json) => _$PersonFromJson(json);
+}
+
+extension JsonWithoutId on Person {
+  String toJsonWithoutId() {
+    final map = toJson();
+    // ignore: cascade_invocations  //remove returns the removed field!, cascade_invocations
+    map.remove('id');
+    return json.encode(map);
+  }
+}
+
+// String toJsonWithoutId(Person p) {
+//   var a = p.toJson();
+//   var b = a.remove('id');
+//   var c = json.encode(a);
+
+//   // final map = p.toJson().remove('id');
+//   // return json.encode(map);
+//   return c;
+// }

learning/demo-app/lib/src/features/rest_crud_demo/domain/person.freezed.dart

@@ -0,0 +1,192 @@
+// coverage:ignore-file
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'person.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+T _$identity<T>(T value) => value;
+
+final _privateConstructorUsedError = UnsupportedError(
+    'It seems like you constructed your class using `MyClass._()`. This constructor is only meant to be used by freezed and you are not supposed to need it nor use it.\nPlease check the documentation here for more information: https://github.com/rrousselGit/freezed#custom-getters-and-methods');
+
+Person _$PersonFromJson(Map<String, dynamic> json) {
+  return _Person.fromJson(json);
+}
+
+/// @nodoc
+mixin _$Person {
+  int get id => throw _privateConstructorUsedError;
+  String get name => throw _privateConstructorUsedError;
+  String get imageUrl => throw _privateConstructorUsedError;
+
+  Map<String, dynamic> toJson() => throw _privateConstructorUsedError;
+  @JsonKey(ignore: true)
+  $PersonCopyWith<Person> get copyWith => throw _privateConstructorUsedError;
+}
+
+/// @nodoc
+abstract class $PersonCopyWith<$Res> {
+  factory $PersonCopyWith(Person value, $Res Function(Person) then) =
+      _$PersonCopyWithImpl<$Res, Person>;
+  @useResult
+  $Res call({int id, String name, String imageUrl});
+}
+
+/// @nodoc
+class _$PersonCopyWithImpl<$Res, $Val extends Person>
+    implements $PersonCopyWith<$Res> {
+  _$PersonCopyWithImpl(this._value, this._then);
+
+  // ignore: unused_field
+  final $Val _value;
+  // ignore: unused_field
+  final $Res Function($Val) _then;
+
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? id = null,
+    Object? name = null,
+    Object? imageUrl = null,
+  }) {
+    return _then(_value.copyWith(
+      id: null == id
+          ? _value.id
+          : id // ignore: cast_nullable_to_non_nullable
+              as int,
+      name: null == name
+          ? _value.name
+          : name // ignore: cast_nullable_to_non_nullable
+              as String,
+      imageUrl: null == imageUrl
+          ? _value.imageUrl
+          : imageUrl // ignore: cast_nullable_to_non_nullable
+              as String,
+    ) as $Val);
+  }
+}
+
+/// @nodoc
+abstract class _$$_PersonCopyWith<$Res> implements $PersonCopyWith<$Res> {
+  factory _$$_PersonCopyWith(_$_Person value, $Res Function(_$_Person) then) =
+      __$$_PersonCopyWithImpl<$Res>;
+  @override
+  @useResult
+  $Res call({int id, String name, String imageUrl});
+}
+
+/// @nodoc
+class __$$_PersonCopyWithImpl<$Res>
+    extends _$PersonCopyWithImpl<$Res, _$_Person>
+    implements _$$_PersonCopyWith<$Res> {
+  __$$_PersonCopyWithImpl(_$_Person _value, $Res Function(_$_Person) _then)
+      : super(_value, _then);
+
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? id = null,
+    Object? name = null,
+    Object? imageUrl = null,
+  }) {
+    return _then(_$_Person(
+      id: null == id
+          ? _value.id
+          : id // ignore: cast_nullable_to_non_nullable
+              as int,
+      name: null == name
+          ? _value.name
+          : name // ignore: cast_nullable_to_non_nullable
+              as String,
+      imageUrl: null == imageUrl
+          ? _value.imageUrl
+          : imageUrl // ignore: cast_nullable_to_non_nullable
+              as String,
+    ));
+  }
+}
+
+/// @nodoc
+@JsonSerializable()
+class _$_Person with DiagnosticableTreeMixin implements _Person {
+  const _$_Person(
+      {required this.id, required this.name, required this.imageUrl});
+
+  factory _$_Person.fromJson(Map<String, dynamic> json) =>
+      _$$_PersonFromJson(json);
+
+  @override
+  final int id;
+  @override
+  final String name;
+  @override
+  final String imageUrl;
+
+  @override
+  String toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) {
+    return 'Person(id: $id, name: $name, imageUrl: $imageUrl)';
+  }
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    properties
+      ..add(DiagnosticsProperty('type', 'Person'))
+      ..add(DiagnosticsProperty('id', id))
+      ..add(DiagnosticsProperty('name', name))
+      ..add(DiagnosticsProperty('imageUrl', imageUrl));
+  }
+
+  @override
+  bool operator ==(dynamic other) {
+    return identical(this, other) ||
+        (other.runtimeType == runtimeType &&
+            other is _$_Person &&
+            (identical(other.id, id) || other.id == id) &&
+            (identical(other.name, name) || other.name == name) &&
+            (identical(other.imageUrl, imageUrl) ||
+                other.imageUrl == imageUrl));
+  }
+
+  @JsonKey(ignore: true)
+  @override
+  int get hashCode => Object.hash(runtimeType, id, name, imageUrl);
+
+  @JsonKey(ignore: true)
+  @override
+  @pragma('vm:prefer-inline')
+  _$$_PersonCopyWith<_$_Person> get copyWith =>
+      __$$_PersonCopyWithImpl<_$_Person>(this, _$identity);
+
+  @override
+  Map<String, dynamic> toJson() {
+    return _$$_PersonToJson(
+      this,
+    );
+  }
+}
+
+abstract class _Person implements Person {
+  const factory _Person(
+      {required final int id,
+      required final String name,
+      required final String imageUrl}) = _$_Person;
+
+  factory _Person.fromJson(Map<String, dynamic> json) = _$_Person.fromJson;
+
+  @override
+  int get id;
+  @override
+  String get name;
+  @override
+  String get imageUrl;
+  @override
+  @JsonKey(ignore: true)
+  _$$_PersonCopyWith<_$_Person> get copyWith =>
+      throw _privateConstructorUsedError;
+}

learning/demo-app/lib/src/features/rest_crud_demo/domain/person.g.dart

@@ -0,0 +1,19 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'person.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_$_Person _$$_PersonFromJson(Map<String, dynamic> json) => _$_Person(
+      id: json['id'] as int,
+      name: json['name'] as String,
+      imageUrl: json['imageUrl'] as String,
+    );
+
+Map<String, dynamic> _$$_PersonToJson(_$_Person instance) => <String, dynamic>{
+      'id': instance.id,
+      'name': instance.name,
+      'imageUrl': instance.imageUrl,
+    };

learning/demo-app/lib/src/features/rest_crud_demo/presentation/details_screen.dart

@@ -0,0 +1,74 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:gap/gap.dart';
+
+import '../../../common_widgets/async_value_widget.dart';
+import '../../../constants/ui_constants.dart';
+import '../../../utils/localization.dart';
+import '../../../utils/logger.dart';
+import '../data/people_repository.dart';
+import '../domain/person.dart';
+
+class DetailsScreen extends ConsumerWidget {
+  const DetailsScreen({super.key, this.id, this.person});
+  final int? id;
+  final Person? person;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    if (id == null) {
+      return Scaffold(
+        appBar: AppBar(
+          title: Text(context.loc.details),
+        ),
+        body: Text(context.loc.error),
+      );
+    } else if (person != null) {
+      return DetailsScreenPlainWidget(person!);
+    } else {
+      // e.g. navigated to details by bookmark
+      return AsyncValueWidget<Person>(
+        value: ref.watch(fetchPersonByIdProvider(id!)),
+        data: DetailsScreenPlainWidget.new,
+      );
+    }
+  }
+}
+
+class DetailsScreenPlainWidget extends StatelessWidget {
+  const DetailsScreenPlainWidget(this.person, {super.key});
+  final Person person;
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(context.loc.details),
+      ),
+      body: Padding(
+        padding: const EdgeInsets.all(UIConstants.defaultPadding),
+        child: Column(
+          children: [
+            Text('hi ${person.name}'),
+            const Gap(UIConstants.verticalItemSpace),
+            if (person.imageUrl.startsWith('http'))
+              Expanded(
+                child: Image(
+                  image: NetworkImage(person.imageUrl),
+                  errorBuilder: (context, error, stackTrace) {
+                    logger.d(
+                      'DetailsScreen - image, url=${person.imageUrl}',
+                      error: error,
+                      stackTrace: stackTrace,
+                    );
+                    return Text(person.imageUrl);
+                  },
+                ),
+              )
+            else
+              Text(person.imageUrl),
+          ],
+        ),
+      ),
+    );
+  }
+}

learning/demo-app/lib/src/features/rest_crud_demo/presentation/edit_person_controller.dart

@@ -0,0 +1,81 @@
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../../../utils/logger.dart';
+import '../data/people_repository.dart';
+import '../domain/person.dart';
+
+part 'edit_person_controller.g.dart';
+
+// in some cases it might be good to store the current selected item in a
+// separate provider
+// final currentPersonProvider = StateProvider<Person?>((ref) {
+//   return null;
+// });
+
+@riverpod
+class EditPersonController extends _$EditPersonController {
+  @override
+  FutureOr<Person?> build() {
+    ref.onDispose(
+      () => logger.i('EditPersonController ----- dispose controller -----'),
+    );
+    state = const AsyncData(null);
+    return state.value;
+  }
+
+  //for non string-based setters and hence input fields without own controllers
+  //use setters like
+  // void setCheckboxField(bool value) {
+  //   state = AsyncData(state.value!.copyWith(isBossy: value));
+  // }
+
+  /// Show the form with the values given by [person].
+  void editPerson(Person person) {
+    state = AsyncData(person);
+  }
+
+  /// Show the form with empty fields, ready to create a new person.
+  void newPerson() {
+    state = const AsyncData(Person(id: -1, name: '', imageUrl: ''));
+  }
+
+  Future<void> delete() async {
+    if (state.value == null || state.value!.id < 0) {
+      return;
+    }
+    state = const AsyncLoading<Person?>();
+    try {
+      final repo = ref.read(peopleRepositoryProvider);
+      await repo.deletePerson(state.value!.id);
+      //this provider does not know this change, hence we need to force a
+      //refresh by invalidating it
+      ref.invalidate(fetchPeopleProvider);
+      state = const AsyncData(null);
+    } catch (error) {
+      state = AsyncError(error, StackTrace.current);
+    }
+  }
+
+  Future<void> save({required String name, required String imageUrl}) async {
+    if (name.isEmpty || state.value == null) {
+      return;
+    }
+    // use copywith to keep id
+    final editedPerson = state.value!.copyWith(name: name, imageUrl: imageUrl);
+    // to keep changes of the form fields, even if we may have an error
+    state = AsyncData(editedPerson);
+    state = const AsyncLoading<Person?>();
+    try {
+      final repo = ref.read(peopleRepositoryProvider);
+      if (editedPerson.id < 0) {
+        await repo.savePerson(person: editedPerson);
+      } else {
+        await repo.updatePerson(person: editedPerson);
+      }
+      ref.invalidate(fetchPeopleProvider);
+      state = const AsyncData(null);
+    } catch (error) {
+      state = AsyncError<Person?>(error, StackTrace.current);
+    }
+  }
+}

learning/demo-app/lib/src/features/rest_crud_demo/presentation/edit_person_controller.g.dart

@@ -0,0 +1,26 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'edit_person_controller.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$editPersonControllerHash() =>
+    r'7c656c78c7d8c60e746ec6bd7ad4e089f2f3fcac';
+
+/// See also [EditPersonController].
+@ProviderFor(EditPersonController)
+final editPersonControllerProvider =
+    AutoDisposeAsyncNotifierProvider<EditPersonController, Person?>.internal(
+  EditPersonController.new,
+  name: r'editPersonControllerProvider',
+  debugGetCreateSourceHash: const bool.fromEnvironment('dart.vm.product')
+      ? null
+      : _$editPersonControllerHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef _$EditPersonController = AutoDisposeAsyncNotifier<Person?>;
+// ignore_for_file: unnecessary_raw_strings, subtype_of_sealed_class, invalid_use_of_internal_member, do_not_use_environment, prefer_const_constructors, public_member_api_docs, avoid_private_typedef_functions

learning/demo-app/lib/src/features/rest_crud_demo/presentation/edit_person_form.dart

@@ -0,0 +1,106 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:gap/gap.dart';
+
+import '../../../common_widgets/error_message_widget.dart';
+import '../../../common_widgets/form_field_widget.dart';
+import '../../../common_widgets/primary_button.dart';
+import '../../../constants/ui_constants.dart';
+import '../../../utils/localization.dart';
+import 'edit_person_controller.dart';
+
+class EditPersonForm extends ConsumerStatefulWidget {
+  const EditPersonForm({super.key});
+
+  @override
+  ConsumerState<EditPersonForm> createState() => _EditPersonFormState();
+}
+
+class _EditPersonFormState extends ConsumerState<EditPersonForm> {
+  final _formKey = GlobalKey<FormState>();
+  static const Key _nameKey = Key('name');
+  static const Key _imageUrlKey = Key('image_url');
+  final _nameController = TextEditingController();
+  final _imageUrlController = TextEditingController();
+  late final EditPersonController _controller;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = ref.read(editPersonControllerProvider.notifier);
+  }
+
+  @override
+  void dispose() {
+    _nameController.dispose();
+    _imageUrlController.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final state = ref.watch(editPersonControllerProvider);
+    if (state.isLoading) {
+      return const CircularProgressIndicator();
+    }
+    if (state.value == null) {
+      return Container();
+    } else {
+      _nameController.text = state.value!.name;
+      _imageUrlController.text = state.value!.imageUrl;
+      return Padding(
+        padding: const EdgeInsets.all(UIConstants.defaultPadding),
+        child: Form(
+          key: _formKey,
+          child: Column(
+            children: [
+              //put here to have both visible, the error and the form
+              if (state.hasError) ErrorMessageWidget(state.error),
+              FormFieldWidget(
+                formFieldKey: _nameKey,
+                controller: _nameController,
+                labelText: context.loc.labelName,
+                required: true,
+              ),
+              const Gap(UIConstants.verticalItemSpace),
+              FormFieldWidget(
+                formFieldKey: _imageUrlKey,
+                controller: _imageUrlController,
+                labelText: context.loc.labelImageUrl,
+              ),
+              const Gap(UIConstants.verticalItemSpace),
+              Row(
+                children: [
+                  PrimaryButton(
+                    label: context.loc.delete,
+                    backgroundColor: Theme.of(context).colorScheme.error,
+                    foregroundColor: Theme.of(context).colorScheme.onError,
+                    onPressed:
+                        state.isLoading ? null : () => {_controller.delete()},
+                    isEnabled: state.value!.id > 0,
+                  ),
+                  Expanded(
+                    child: PrimaryButton(
+                      label: context.loc.save,
+                      onPressed: state.isLoading
+                          ? null
+                          : () => {
+                                if (_formKey.currentState!.validate())
+                                  {
+                                    _controller.save(
+                                      name: _nameController.text,
+                                      imageUrl: _imageUrlController.text,
+                                    ),
+                                  },
+                              },
+                    ),
+                  ),
+                ],
+              ),
+            ],
+          ),
+        ),
+      );
+    }
+  }
+}

learning/demo-app/lib/src/features/rest_crud_demo/presentation/people_screen.dart

@@ -0,0 +1,82 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../../common_widgets/async_value_widget.dart';
+import '../../../common_widgets/two_panel_widget.dart';
+import '../../../routing/app_router.dart';
+import '../../../utils/localization.dart';
+import '../data/people_repository.dart';
+import '../domain/person.dart';
+import 'edit_person_controller.dart';
+import 'edit_person_form.dart';
+
+class PeopleScreen extends ConsumerWidget {
+  const PeopleScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return Scaffold(
+      appBar: AppBar(
+        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+        title: Text(context.loc.appTitle),
+      ),
+      body: TwoPanelWidget(
+        firstPanel: RefreshIndicator(
+          //pull to refresh
+          onRefresh: () {
+            ref.invalidate(fetchPeopleProvider);
+            return ref.read(fetchPeopleProvider.future);
+          },
+          child: AsyncValueWidget<List<Person>>(
+            value: ref.watch(fetchPeopleProvider),
+            data: (people) => people.isEmpty
+                ? Center(
+                    child: Text(
+                      context.loc.noItems,
+                      style: Theme.of(context).textTheme.displaySmall,
+                      textAlign: TextAlign.center,
+                    ),
+                  )
+                : ListView.builder(
+                    itemCount: people.length,
+                    itemBuilder: (context, index) {
+                      return ListTile(
+                        title: Text(people[index].name),
+                        onTap: () {
+                          context.goNamed(
+                            SubRoutes.details.name,
+                            pathParameters: {
+                              Parameter.id.name: people[index].id.toString(),
+                            },
+                            extra: people[index],
+                          );
+                        },
+                        trailing: IconButton(
+                          icon: const Icon(Icons.edit),
+                          tooltip: 'Edit '.hardcoded + people[index].name,
+                          onPressed: () {
+                            ref
+                                .read(
+                                  editPersonControllerProvider.notifier,
+                                )
+                                .editPerson(people[index]);
+                          },
+                        ),
+                      );
+                    },
+                  ),
+          ),
+        ),
+        secondPanel: const EditPersonForm(),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: () {
+          ref.read(editPersonControllerProvider.notifier).newPerson();
+        },
+        tooltip: 'click to add a new person'.hardcoded,
+        child: const Icon(Icons.add),
+      ),
+    );
+  }
+}

learning/demo-app/lib/src/routing/app_router.dart

@@ -0,0 +1,109 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+import '../features/counter/presentation/counter_screen.dart';
+import '../features/rest_crud_demo/domain/person.dart';
+import '../features/rest_crud_demo/presentation/details_screen.dart';
+import '../features/rest_crud_demo/presentation/people_screen.dart';
+import 'scaffold_with_navigation.dart';
+
+part 'app_router.g.dart';
+
+// general ideas on navigation see https://m2.material.io/design/navigation/understanding-navigation.html#forward-navigation
+
+// shell routes, appear in the bottom navigation
+// see https://pub.dev/documentation/go_router/latest/go_router/ShellRoute-class.html
+enum TopLevelDestinations { people, counter }
+
+// GlobalKey is a factory, hence each call creates a key
+//this is root, even if it navigates to people, it needs a separate key!!!
+final _rootNavigatorKey = GlobalKey<NavigatorState>();
+final _peopleNavigatorKey =
+    GlobalKey<NavigatorState>(debugLabel: TopLevelDestinations.people.name);
+final _counterNavigatorKey =
+    GlobalKey<NavigatorState>(debugLabel: TopLevelDestinations.counter.name);
+
+// other destinations, reachable from a top level destination
+enum SubRoutes { details }
+
+enum Parameter { id }
+
+//https://github.com/flutter/packages/blob/main/packages/go_router/example/lib/stateful_shell_route.dart
+
+@Riverpod(keepAlive: true)
+GoRouter goRouter(GoRouterRef ref) {
+  return GoRouter(
+    initialLocation: '/${TopLevelDestinations.people.name}',
+    navigatorKey: _rootNavigatorKey,
+    debugLogDiagnostics: true,
+    routes: [
+      // Stateful navigation based on:
+      // https://github.com/flutter/packages/blob/main/packages/go_router/example/lib/stateful_shell_route.dart
+      StatefulShellRoute.indexedStack(
+        builder: (context, state, navigationShell) {
+          return ScaffoldWithNavigation(navigationShell: navigationShell);
+        },
+        branches: [
+          StatefulShellBranch(
+            navigatorKey: _peopleNavigatorKey,
+            routes: [
+              // base route people
+              GoRoute(
+                path: '/${TopLevelDestinations.people.name}', // path: /people
+                name: TopLevelDestinations.people.name,
+                pageBuilder: (context, state) => NoTransitionPage(
+                  key: state.pageKey,
+                  child: const PeopleScreen(),
+                ),
+                routes: <RouteBase>[
+                  // The details screen to display stacked on navigator of the
+                  // first tab. This will cover screen A but not the application
+                  // shell (bottom navigation bar).
+                  GoRoute(
+                    path: '${SubRoutes.details.name}/:${Parameter.id.name}',
+                    name: SubRoutes.details.name,
+                    builder: (BuildContext context, GoRouterState state) {
+                      // alternatively use https://pub.dev/documentation/go_router/latest/topics/Type-safe%20routes-topic.html
+                      final id =
+                          int.parse(state.pathParameters[Parameter.id.name]!);
+                      final person = _extractPersonFromExtra(state.extra);
+                      return DetailsScreen(id: id, person: person);
+                    },
+                  ),
+                ],
+              ),
+            ],
+          ),
+          StatefulShellBranch(
+            navigatorKey: _counterNavigatorKey,
+            routes: [
+              GoRoute(
+                path: '/${TopLevelDestinations.counter.name}',
+                name: TopLevelDestinations.counter.name,
+                pageBuilder: (context, state) => NoTransitionPage(
+                  key: state.pageKey,
+                  child: const CounterScreen(),
+                ),
+              ),
+            ],
+          ),
+        ],
+      ),
+    ],
+  );
+}
+
+Person? _extractPersonFromExtra(Object? extra) {
+  return extra == null
+      ? null
+      : extra is Person
+          ? extra
+          : extra is Map // if you come back from bottom navigation, e.g. look
+              // at details of a person, go to counter via bottom navigation,
+              // use bottom navigation to go to people/home
+              ? Person.fromJson(
+                  extra as Map<String, Object?>,
+                )
+              : null;
+}

learning/demo-app/lib/src/routing/app_router.g.dart

@@ -0,0 +1,23 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'app_router.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$goRouterHash() => r'caf38f1ae54f10aea6450bd6fc62dae849543827';
+
+/// See also [goRouter].
+@ProviderFor(goRouter)
+final goRouterProvider = Provider<GoRouter>.internal(
+  goRouter,
+  name: r'goRouterProvider',
+  debugGetCreateSourceHash:
+      const bool.fromEnvironment('dart.vm.product') ? null : _$goRouterHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef GoRouterRef = ProviderRef<GoRouter>;
+// ignore_for_file: unnecessary_raw_strings, subtype_of_sealed_class, invalid_use_of_internal_member, do_not_use_environment, prefer_const_constructors, public_member_api_docs, avoid_private_typedef_functions

learning/demo-app/lib/src/routing/scaffold_with_navigation.dart

@@ -0,0 +1,133 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+import '../constants/breakpoint.dart';
+import '../utils/localization.dart';
+
+// see https://github.com/flutter/packages/blob/main/packages/go_router/example/lib/stateful_shell_route.dart
+// and https://github.com/bizz84/tmdb_movie_app_riverpod/blob/main/lib/src/routing/scaffold_with_nested_navigation.dart
+class NavigationItem {
+  NavigationItem({required this.icon, required this.selectedIcon});
+  final IconData icon;
+  final IconData selectedIcon;
+}
+
+final _navigationList = (
+  people: NavigationItem(icon: Icons.home_outlined, selectedIcon: Icons.home),
+  counter: NavigationItem(
+    icon: Icons.plus_one_outlined,
+    selectedIcon: Icons.plus_one,
+  ),
+);
+
+class ScaffoldWithNavigation extends StatelessWidget {
+  const ScaffoldWithNavigation({
+    required this.navigationShell,
+    Key? key,
+  }) : super(key: key ?? const ValueKey('ScaffoldWithNavigation'));
+  final StatefulNavigationShell navigationShell;
+
+  void _goBranch(int index) {
+    navigationShell.goBranch(
+      index,
+      initialLocation: index == navigationShell.currentIndex,
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final size = MediaQuery.sizeOf(context);
+    if (size.width < Breakpoint.tablet) {
+      return ScaffoldWithNavigationBar(
+        body: navigationShell,
+        currentIndex: navigationShell.currentIndex,
+        onDestinationSelected: _goBranch,
+      );
+    } else {
+      return ScaffoldWithNavigationRail(
+        body: navigationShell,
+        currentIndex: navigationShell.currentIndex,
+        onDestinationSelected: _goBranch,
+      );
+    }
+  }
+}
+
+class ScaffoldWithNavigationBar extends StatelessWidget {
+  const ScaffoldWithNavigationBar({
+    required this.body,
+    required this.currentIndex,
+    required this.onDestinationSelected,
+    super.key,
+  });
+  final Widget body;
+  final int currentIndex;
+  final ValueChanged<int> onDestinationSelected;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: body,
+      bottomNavigationBar: NavigationBar(
+        selectedIndex: currentIndex,
+        destinations: [
+          NavigationDestination(
+            icon: Icon(_navigationList.people.icon),
+            selectedIcon: Icon(_navigationList.people.selectedIcon),
+            label: context.loc.home,
+          ),
+          NavigationDestination(
+            icon: Icon(_navigationList.counter.icon),
+            selectedIcon: Icon(_navigationList.counter.selectedIcon),
+            label: context.loc.counter,
+          ),
+        ],
+        onDestinationSelected: onDestinationSelected,
+      ),
+    );
+  }
+}
+
+class ScaffoldWithNavigationRail extends StatelessWidget {
+  const ScaffoldWithNavigationRail({
+    required this.body,
+    required this.currentIndex,
+    required this.onDestinationSelected,
+    super.key,
+  });
+  final Widget body;
+  final int currentIndex;
+  final ValueChanged<int> onDestinationSelected;
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Row(
+        children: [
+          NavigationRail(
+            selectedIndex: currentIndex,
+            onDestinationSelected: onDestinationSelected,
+            labelType: NavigationRailLabelType.all,
+            destinations: <NavigationRailDestination>[
+              NavigationRailDestination(
+                icon: Icon(_navigationList.people.icon),
+                selectedIcon: Icon(_navigationList.people.selectedIcon),
+                label: Text(context.loc.home),
+              ),
+              NavigationRailDestination(
+                icon: Icon(_navigationList.counter.icon),
+                selectedIcon: Icon(_navigationList.counter.selectedIcon),
+                label: Text(context.loc.counter),
+              ),
+            ],
+          ),
+          const VerticalDivider(thickness: 1, width: 1),
+          // This is the main content.
+          Expanded(
+            child: body,
+          ),
+        ],
+      ),
+    );
+  }
+}

learning/demo-app/lib/src/utils/dio_provider.dart

@@ -0,0 +1,18 @@
+import 'package:dio/dio.dart';
+import 'package:pretty_dio_logger/pretty_dio_logger.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'dio_provider.g.dart';
+
+@riverpod
+Dio dio(DioRef ref) {
+  final dio = Dio();
+  dio.interceptors.add(
+    PrettyDioLogger(
+      requestHeader: true,
+      responseBody: false,
+      responseHeader: true,
+    ),
+  );
+  return dio;
+}

learning/demo-app/lib/src/utils/dio_provider.g.dart

@@ -0,0 +1,23 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'dio_provider.dart';
+
+// **************************************************************************
+// RiverpodGenerator
+// **************************************************************************
+
+String _$dioHash() => r'50bc684111bbcb930ccaac200da3a7ad761e689b';
+
+/// See also [dio].
+@ProviderFor(dio)
+final dioProvider = AutoDisposeProvider<Dio>.internal(
+  dio,
+  name: r'dioProvider',
+  debugGetCreateSourceHash:
+      const bool.fromEnvironment('dart.vm.product') ? null : _$dioHash,
+  dependencies: null,
+  allTransitiveDependencies: null,
+);
+
+typedef DioRef = AutoDisposeProviderRef<Dio>;
+// ignore_for_file: unnecessary_raw_strings, subtype_of_sealed_class, invalid_use_of_internal_member, do_not_use_environment, prefer_const_constructors, public_member_api_docs, avoid_private_typedef_functions

learning/demo-app/lib/src/utils/localization.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+/// A simple placeholder that can be used to search all the hardcoded strings
+/// in the code (useful to identify strings that need to be localized).
+/// thanks to https://github.com/bizz84/starter_architecture_flutter_firebase/blob/master/lib/src/localization/string_hardcoded.dart
+extension StringHardcoded on String {
+  String get hardcoded => this;
+}
+
+//thanks to https://codewithandrea.com/articles/flutter-localization-build-context-extension/
+extension LocalizedBuildContext on BuildContext {
+  AppLocalizations get loc => AppLocalizations.of(this);
+}

learning/demo-app/lib/src/utils/logger.dart

@@ -0,0 +1,13 @@
+import 'package:logger/logger.dart';
+
+const Level loggerLevel = Level.trace;
+
+/// Logger for the app.
+Logger logger = Logger(
+  printer: PrettyPrinter(
+    methodCount: 1,
+    errorMethodCount: 5,
+    lineLength: 90,
+  ),
+  level: loggerLevel,
+);