### Install Stacked CLI

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Install the stacked_cli package globally on your machine to start using the CLI commands.

```bash
dart pub global activate stacked_cli  
```

--------------------------------

### Multiple Streams Example ViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Demonstrates how to implement a MultipleStreamViewModel by overriding streamsMap to provide multiple streams with unique keys. Includes example streams for integers and strings.

```dart
const String _NumbersStreamKey = 'numbers-stream';  
const String _StringStreamKey = 'string-stream';  
  
class MultipleStreamsExampleViewModel extends MultipleStreamViewModel {  
  int numbersStreamDelay = 500;  
  int stringStreamDelay = 2000;  
  
  @override  
  Map<String, StreamData> get streamsMap => {  
        _NumbersStreamKey: StreamData<int>(numbersStream(numbersStreamDelay)),  
        _StringStreamKey: StreamData<String>(stringStream(stringStreamDelay)),  
      };
  
  Stream<int> numbersStream([int delay = 500]) async* {  
    var random = Random();  
    while (true) {  
      await Future.delayed(Duration(milliseconds: delay));  
      yield random.nextInt(999);  
    }  
  }  
  
  Stream<String> stringStream([int delay = 2000]) async* {  
    var random = Random();  
    while (true) {  
      await Future.delayed(Duration(milliseconds: delay));  
      var randomLength = random.nextInt(50);  
      var randomString = '';  
      for (var i = 0; i < randomLength; i++) {  
        randomString += String.fromCharCode(random.nextInt(50));  
      }  
      yield randomString;  
    }  
  }  
}
```

--------------------------------

### Stacked CLI Configuration File

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Example of a `stacked.json` file used to configure Stacked CLI paths and settings for custom project structures.

```json
{
  "bottom_sheets_path": "lib/ui/custom_bottom_sheets",
  "dialogs_sheets_path": "lib/ui/custom_dialogs",
  "services_path": "lib/services/custom",
  "stacked_app_file_path": "lib/app/custom_app.dart",
  "test_helpers_file_path": "lib/helpers/custom_test_helpers.dart"
}
```

--------------------------------

### Activate Stacked CLI

Source: https://stacked.filledstacks.com/docs/getting-started/overview

Install the stacked_cli package globally using Dart pub to access Stacked development tools.

```bash
dart pub global activate stacked_cli  

```

--------------------------------

### StreamCounterViewModel and StreamCounterView Example

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Demonstrates how to use StreamViewModel to listen to a stream of integers and display the data in a Flutter widget. Includes the ViewModel, the View, and a sample Service that provides the stream.

```dart
class StreamCounterViewModel extends StreamViewModel<int> {
  
  String get title => 'This is the time since epoch in seconds \n $data';  
  
  @override  
  Stream<int> get stream => locator<EpochService>().epochUpdatesNumbers();  
}
  
class StreamCounterView extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ViewModelBuilder<StreamCounterViewModel>.reactive(
      builder: (context, viewModel, child) => Scaffold(
            body: Center(
              child: Text(viewModel.title),
            ),
          ),
      viewModelBuilder: () => StreamCounterViewModel(),
    );
  }
}

@lazySingleton
class EpochService {
  Stream<int> epochUpdatesNumbers() async* {
    while (true) {
      await Future.delayed(const Duration(seconds: 2));
      yield DateTime.now().millisecondsSinceEpoch;
    }
  }
}
```

--------------------------------

### Minimal StreamViewModel Implementation

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Shows the essential two lines of code required to create a ViewModel that listens to a stream. This snippet focuses on the core setup for StreamViewModel.

```dart
class StreamCounterViewModel extends StreamViewModel<int> {
  @override
  Stream<int> get stream => locator<EpochService>().epochUpdatesNumbers();
}
```

--------------------------------

### Add a New Service

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Generate a new Service and add it to your application's dependency injection setup in app.dart.

```bash
stacked create service stripe  
```

--------------------------------

### ViewModel with Direct HTTP Request and Deserialization

Source: https://stacked.filledstacks.com/docs/in-depth/services

This example shows a ViewModel directly handling HTTP requests, response validation, and data deserialization. It's an anti-pattern that violates the single responsibility principle.

```dart
class HomeViewModel extends BaseViewModel {
  List<Artist> _artists = [];

  Future<void> fetchArtists() async {
    // #1: Structure the http request
    final response = await http.get(Uri.https('venu.is', '/artists'));

    // #2: Validate the request is successful
    if (response.statusCode < 400) {
      // #3: Convert the response into a map
      final responseBodyAsMap = jsonDecode(response.body);

      // #4: Get relevant data from the response
      final artistMaps =
          responseBodyAsMap['data'] as List<Map<String, dynamic>>;

      // #5: Deserialize into a list of artists
      _artists = artistMaps.map(Artist.fromJson).toList();
    }
  }
}

class Artist {
  final String name;
  final String coverImage;

  Artist({required this.name, required this.coverImage});

  factory Artist.fromJson(Map<String, dynamic> data) => Artist(
        name: data['name'],
        coverImage: data['coverImage'],
      );
}

```

--------------------------------

### HomeView with IndexTrackingViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Example of using IndexTrackingViewModel in a StatelessWidget to manage the current index for navigation, such as a bottom navigation bar. It integrates with ViewModelBuilder.reactive.

```dart
class HomeView extends StatelessWidget {  
  const HomeView({Key key}) : super(key: key);  
  
  @override  
  Widget build(BuildContext context) {  
    return ViewModelBuilder<HomeViewModel>.reactive(  
      builder: (context, viewModel, child) => Scaffold(  
        body: getViewForIndex(viewModel.currentIndex),  
        bottomNavigationBar: BottomNavigationBar(  
          type: BottomNavigationBarType.fixed,  
          backgroundColor: Colors.grey[800],  
          currentIndex: viewModel.currentTabIndex,  
          onTap: viewModel.setIndex,  
          items: [  
            BottomNavigationBarItem(  
              title: Text('Posts'),  
              icon: Icon(Icons.art_track),  
            ),  
            BottomNavigationBarItem(  
              title: Text('Todos'),  
              icon: Icon(Icons.list),  
            ),  
          ],  
        ),  
      ),  
      viewModelBuilder: () => HomeViewModel(),  
    );  
  }  
  
  Widget getViewForIndex(int index) {  
    switch (index) {  
      case 0:  
        return PostsView();  
      case 1:  
        return TodosView();  
    }  
  }  
}
```

--------------------------------

### Replace NavigationService with RouterService in app.dart

Source: https://stacked.filledstacks.com/docs/stacked-router/routing-basics

Replace the NavigationService with RouterService in your app.dart file to enable web-supported navigation. This setup is automatically included if you generate a Stacked project with the '--t web' option.

```dart
@StackedApp(
    routes: [ ... ],
    dependencies: [
    LazySingleton(classType: RouterService),
    LazySingleton(classType: DialogService),
    LazySingleton(classType: BottomSheetService),
    ]
)
class App {}
```

--------------------------------

### Define a Custom Validator

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Create a static function to validate input. This function should accept a nullable string and return a nullable string (the error message). Numbers are not allowed in this example.

```dart
class TextReverseValidators {
  static String? validateReverseText(String? value) {
    if (value == null) {
      return null;
    }

    if (value.contains(RegExp(r'[0-9]'))) {
      return 'No numbers allowed';
    }
  }
}
```

--------------------------------

### Implement Startup Logic

Source: https://stacked.filledstacks.com/docs/getting-started/startup-logic

Use this ViewModel to check user authentication and navigate to the appropriate view upon app startup. Ensure AuthenticationService and NavigationService are available via the locator.

```dart
class StartupViewModel extends BaseViewModel {  
  // 1. Get the Authentication and NavigationService  
  final _authenticationService = locator<AuthenticationService>();  
  final _navigationService = locator<NavigationService>();  
  
  Future runStartupLogic() async {  
    // 2. Check if the user is logged in  
    if (_authenticationService.userLoggedIn()) {  
      // 3. Navigate to HomeView  
      _navigationService.replaceWith(Routes.homeView);  
    } else {  
      // 4. Or navigate to LoginView  
      _navigationService.replaceWith(Routes.loginView);  
    }  
  }  
}  

```

--------------------------------

### Create Login View

Source: https://stacked.filledstacks.com/docs/getting-started/startup-logic

Generates a new LoginView using the Stacked CLI. This view will be used for navigation after the startup logic.

```bash
stacked create view login  
```

--------------------------------

### Navigate to Home View with Argument

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Navigates to the HomeView and passes the required 'startingIndex' argument.

```dart
_navigationService.navigateToHomeView(startingIndex: 0);

```

--------------------------------

### Create a New View with Stacked CLI

Source: https://stacked.filledstacks.com/docs/getting-started/how-it-works

Use the Stacked CLI to generate the necessary files for a new View and its associated ViewModel.

```bash
stacked create view counter  

```

--------------------------------

### Home View Constructor with Argument

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Defines the HomeView with a required 'startingIndex' argument in its constructor.

```dart
class HomeView extends StackedView<HomeViewModel> {
  final int startingIndex;
  const HomeView({Key? key, required this.startingIndex}) : super(key: key);
  ...
}

```

--------------------------------

### Create Stacked Service

Source: https://stacked.filledstacks.com/docs/in-depth/services

Command to generate a new service, including its implementation and unit test mock, and register it with the service locator.

```bash
stacked create service api

```

--------------------------------

### Navigate to Counter View

Source: https://stacked.filledstacks.com/docs/getting-started/how-it-works

Modify the StartupViewModel to navigate to the CounterView upon application startup.

```dart
_navigationService.replaceWithCounterView();

```

--------------------------------

### Run a Stacked App

Source: https://stacked.filledstacks.com/docs/getting-started/overview

Execute your newly created Stacked application on a connected device or emulator using the standard Flutter command.

```bash
flutter run  

```

--------------------------------

### Create a New Widget with Stacked CLI

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Execute this command from your Stacked application's root folder to generate a new widget and its associated WidgetModel. The command also creates the WidgetModel test file.

```bash
stacked create widget users_list  
```

--------------------------------

### Create a View with Stacked CLI

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Use the Stacked CLI to generate a new view for your form. This command initializes the basic structure for a new view.

```bash
stacked create view textReverse  

```

--------------------------------

### Replace with Home View with Argument

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Replaces the current view with HomeView, passing the required 'startingIndex' argument.

```dart
_navigationService.replaceWithHomeView(startingIndex: 0);

```

--------------------------------

### Basic IndexTrackingViewModel Implementation

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

A minimal implementation of IndexTrackingViewModel, showing how to extend it for basic index tracking functionality.

```dart
class HomeViewModel extends IndexTrackingViewModel {}  
```

--------------------------------

### Create a New Stacked App

Source: https://stacked.filledstacks.com/docs/getting-started/overview

Generate a new Stacked Flutter application with the default project structure and configurations.

```bash
stacked create app my_first_app  

```

--------------------------------

### Create a New View with Stacked CLI

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

This command generates all necessary files for a new View, including the View, ViewModel, and test files. It also automatically adds the route to your app.dart if template identifiers are present.

```bash
stacked create view profile
```

--------------------------------

### ArtistService Implementation

Source: https://stacked.filledstacks.com/docs/in-depth/services

This snippet demonstrates an App Service class that orchestrates calls to other services (Database, Authentication, API) to fetch and save artist data. It assumes other services are already created and locatable via a 'locator'.

```dart
class ArtistService {
  final _databaseService = locator<DatabaseService>();
  final _authenticationService = locator<AuthenticationService>();
  final _apiService = locator<ApiService>();

  Future<List<Artist>> getArtists() async {
    // Check if user is logged in
    if (_authenticationService.userLoggedIn()) {
      // Get the artists from the backend
      final newArtists = await _apiService.getArtists();

      // Save to the database
      await _databaseService.saveArtists(newArtists);

      return newArtists;
    }

    throw Exception('User must be logged in to see artists');
  }
}
```

--------------------------------

### Create Authentication Service

Source: https://stacked.filledstacks.com/docs/getting-started/startup-logic

Generates a new AuthenticationService using the Stacked CLI. This service will be used to check user login status.

```bash
stacked create service authentication  
```

--------------------------------

### Create a New Dialog with Stacked CLI

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Run this command from your Stacked application's root folder to create a new dialog. It generates the dialog file, adds it to app.dart, and optionally creates a DialogModel and unit test.

```bash
stacked create dialog error  
```

--------------------------------

### Implement AuthenticationService

Source: https://stacked.filledstacks.com/docs/getting-started/startup-logic

Provides a basic implementation for the AuthenticationService. The `userLoggedIn` function currently returns a static true value for demonstration purposes.

```dart
class AuthenticationService {
  bool userLoggedIn() {
    return true;
  }
}

```

--------------------------------

### Basic Counter ViewModel

Source: https://stacked.filledstacks.com/docs/getting-started/how-it-works

Create a ViewModel by extending BaseViewModel to manage state and actions. Use rebuildUi() to notify the UI of changes.

```dart
class CounterViewModel extends BaseViewModel {
    int _counter = 0;
    int get counter => _counter;

    void incrementCounter() {
      _counter++;
      rebuildUi();
    }
}

```

--------------------------------

### MultipleFuturesExampleView UI

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

A StatelessWidget that uses ViewModelBuilder to connect to the MultipleFuturesExampleViewModel. It displays fetched data or loading indicators based on the ViewModel's state for each future.

```dart
class MultipleFuturesExampleView extends StatelessWidget {  
  
  @override  
  Widget build(BuildContext context) {  
    return ViewModelBuilder<MultipleFuturesExampleViewModel>.reactive(  
      builder: (context, viewModel, child) => Scaffold(  
            body: Center(  
              child: Row(  
                mainAxisSize: MainAxisSize.min,  
                children: <Widget>[  
                  Container(  
                    width: 50,  
                    height: 50,  
                    alignment: Alignment.center,  
                    color: Colors.yellow,  
                    // Show busy for number future until the data is back or has failed  
                    child: viewModel.fetchingNumber  
                        ? CircularProgressIndicator()  
                        : Text(viewModel.fetchedNumber.toString()),  
                  ),  
                  SizedBox(  
                    width: 20,  
                  ),  
                  Container(  
                    width: 50,  
                    height: 50,  
                    alignment: Alignment.center,  
                    color: Colors.red,  
                    // Show busy for string future until the data is back or has failed  
                    child: viewModel.fetchingString  
                        ? CircularProgressIndicator()  
                        : Text(viewModel.fetchedString),  
                  ),  
                ],  
              ),  
            ),  
          ),  
      viewModelBuilder: () => MultipleFuturesExampleViewModel());  
  }  
}  

```

--------------------------------

### Create Service Mock

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this comment to `test_helpers.dart` to indicate where a new service mock should be created and registered.

```dart
// @stacked-mock-create  
```

--------------------------------

### Implementing ReactiveViewModel for Service Listening

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Extends ReactiveViewModel and implements `listenableServices` to react to changes in services. The service must use `ListenableServiceMixin` and `listenToReactiveValues`.

```dart
class AnyViewModel extends ReactiveViewModel {
  final _postsService = locator<PostsService>();

  int get postCount => _postsService.postCount;

  @override
  List<ListenableServiceMixin> get listenableServices => [_postsService];
}

```

--------------------------------

### Navigate to Home View

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Navigates to the HomeView by adding it to the top of the navigation stack.

```dart
_navigationService.navigateToHomeView();

```

--------------------------------

### ViewModel Using Facade Service

Source: https://stacked.filledstacks.com/docs/in-depth/services

The ViewModel now delegates the data fetching and deserialization to the ApiService, simplifying its own responsibilities to state management.

```dart
class HomeViewModel extends BaseViewModel {
  final _apiService = locator<ApiService>();
  List<Artist> _artists = [];

  Future<void> fetchArtists() async {
    _artists = await _apiService.getArtists();

    // Do some stuff with artists or extract additional state e.g.
    // empty state, multi select, etc ...
  }
}

```

--------------------------------

### Facade Service Implementation

Source: https://stacked.filledstacks.com/docs/in-depth/services

This ApiService encapsulates the HTTP request and data deserialization logic, providing a clean interface for other parts of the application.

```dart
class ApiService {
  Future<List<Artist>> getArtists() async {
    final response = await http.get(Uri.https('venu.is', '/artists'));
    if (response.statusCode < 400) {
      final responseBodyAsMap = jsonDecode(response.body);
      final artistMaps =
          responseBodyAsMap['data'] as List<Map<String, dynamic>>;
      return artistMaps.map(Artist.fromJson).toList();
    }

    throw Exception('Response Code: ${response.statusCode} - ${response.body}');
  }
}

```

--------------------------------

### Update Stacked CLI

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Run this command to update the stacked_cli application to the latest version. It is a shortcut for 'dart pub global activate stacked_cli'.

```bash
stacked update
```

--------------------------------

### Clear Stack and Show Home View

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Clears the entire navigation stack and then displays the HomeView.

```dart
_navigationService.clearStackAndShow(Routes.homeView);

```

--------------------------------

### App Routes Configuration

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Defines the routes for a Stacked application. Views are automatically added when using the CLI.

```dart
@StackedApp(routes: [
  MaterialRoute(page: StartupView),
  MaterialRoute(page: HomeView),
  MaterialRoute(page: CounterView),
  // @stacked-route
])
class App {}

```

--------------------------------

### Displaying Data from FutureViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Use ViewModelBuilder to connect your View to the FutureExampleViewModel. The UI can conditionally display a loading indicator or the fetched data based on the viewModel.isBusy and viewModel.data properties.

```dart
class FutureExampleView extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ViewModelBuilder<FutureExampleViewModel>.reactive(
      builder: (context, viewModel, child) => Scaffold(
        body: Center(
          // viewModel will indicate busy until the future is fetched  
          child: viewModel.isBusy ? CircularProgressIndicator() : Text(viewModel.data),
        ),
      ),
      viewModelBuilder: () => FutureExampleViewModel(),
    );
  }
}
```

--------------------------------

### ViewModel Error Handling with runBusyFuture

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Demonstrates how runBusyFuture catches exceptions, sets the busy state, and stores the error. Use `hasError` and `modelError` to access the error when no key is provided.

```dart
class ErrorExampleViewModel extends BaseViewModel {
  Future longUpdateStuff() async {
    // Sets busy to true before starting future and sets it to false after executing
    // You can also pass in an object as the busy object. Otherwise it'll use the ViewModel
    var result = await runBusyFuture(updateStuff());
  }

  Future updateStuff() async {
    await Future.delayed(const Duration(seconds: 3));
    throw Exception('Things went wrong');
  }
}

```

--------------------------------

### Build a Custom Transition Widget

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Create a static function with the signature `Widget Function(BuildContext, Animation<double>, Animation<double>, Widget child)` to build your own custom transitions using Flutter's animation widgets.

```dart
import 'package:animations/animations.dart';
import 'package:flutter/material.dart';

class CustomRouteTransition {
  static Widget sharedAxis(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation, Widget child) {

    // Here you can use any Existing Transition class in Flutter
    return SharedAxisTransition(
      animation: animation,
      secondaryAnimation: secondaryAnimation,
      transitionType: SharedAxisTransitionType.scaled,
      child: child,
    );
  }
}

```

--------------------------------

### Default Stacked CLI Configuration

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

This JSON object represents the default configuration for the Stacked CLI. It specifies paths for various project directories like UI components, services, and test files, along with other settings such as line length and web preference.

```json
{
    "bottom_sheets_path": "ui/bottom_sheets",
    "dialogs_path": "ui/dialogs",
    "line_length": 80,
    "locator_name": "locator",
    "prefer_web": true,
    "register_mocks_function": "registerServices",
    "services_path": "services",
    "stacked_app_file_path": "app/app.dart",
    "test_helpers_file_path": "helpers/test_helpers.dart",
    "test_services_path": "services",
    "test_views_path": "viewmodels",
    "test_widgets_path": "widget_models",
    "v1": false,
    "views_path": "ui/views",
    "widgets_path": "ui/widgets/common"
}
```

--------------------------------

### Use Custom Built Transition

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Integrate your custom transition builder by assigning it to the `transitionsBuilder` property in `CustomRoute` at the app level or when navigating.

```dart
// In app.dart
CustomRoute(
  page: CounterView,
  transitionsBuilder: CustomRouteTransition.sharedAxis,
),

// When navigating
await _navigationService.navigateTo(
  Routes.secondView,
  transition: transitionsBuilder: CustomRouteTransition.sharedAxis,
);

```

--------------------------------

### BaseViewModel Implementation with State Handling

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Extend BaseViewModel to manage presentation logic, busy states for specific objects, and overall ViewModel busy states. Use runBusyFuture to automatically handle busy states during asynchronous operations.

```dart
class WidgetOneViewModel extends BaseViewModel {
  Human _currentHuman;
  Human get currentHuman => _currentHuman;

  void setBusyOnProperty() {
    setBusyForObject(_currentHuman, true);
    // Fetch updated human data
    setBusyForObject(_currentHuman, false);
  }

  void setModelBusy() {
    setBusy(true);
    // Do things here
    setBusy(false);
  }

  Future longUpdateStuff() async {
    // Sets busy to true before starting future and sets it to false after executing
    // You can also pass in an object as the busy object. Otherwise it'll use the ViewModel
    var result = await runBusyFuture(updateStuff());
  }

  Future updateStuff() {
    return Future.delayed(const Duration(seconds: 3));
  }
}
```

--------------------------------

### Register Service in `registerServices`

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this comment to `test_helpers.dart` to indicate where a service should be registered within the `registerServices` function.

```dart
// @stacked-mock-register  
```

--------------------------------

### Configure Stacked Logger

Source: https://stacked.filledstacks.com/docs/in-depth/logger

Add the StackedLogger to your StackedApp configuration to enable logging.

```dart
@StackedApp(
  logger: StackedLogger(),
)

```

--------------------------------

### ViewModel Error Handling with a Specific Key

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Shows how to use runBusyFuture with a specific key to manage busy states and errors. Errors can be retrieved using `viewModel.error(key)` or checked with `viewModel.hasErrorForKey(key)`.

```dart
const String BusyObjectKey = 'my-busy-key';

class BusyExampleViewModel extends BaseViewModel {
  Future longUpdateStuff() async {
    // Sets busy to true before starting future and sets it to false after executing
    // You can also pass in an object as the busy object. Otherwise it'll use the ViewModel
    var result = await runBusyFuture(updateStuff(), busyObject: BusyObjectKey);
  }

  Future updateStuff() {
    return Future.delayed(const Duration(seconds: 3));
  }
}

```

--------------------------------

### Replace with Home View

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Replaces the current view with the HomeView on the navigation stack. Can optionally pass arguments.

```dart
_navigationService.replaceWith(Routes.homeView);

```

--------------------------------

### Navigate Back

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Navigates back to the previous view on the navigation stack.

```dart
_navigationService.back();

```

--------------------------------

### Configure LoginView Background

Source: https://stacked.filledstacks.com/docs/getting-started/startup-logic

Sets the background color of the LoginView to red. This is a placeholder for the actual login UI.

```dart
class LoginView extends StackedView<LoginViewModel> {
  const LoginView({Key? key}) : super(key: key);

  @override
  Widget builder(
    BuildContext context,
    LoginViewModel viewModel,
    Widget? child,
  ) {
    return Scaffold(
      backgroundColor: Colors.red,
      body: Container(
        padding: const EdgeInsets.only(left: 25.0, right: 25.0),
      ),
    );
  }

  @override
  LoginViewModel viewModelBuilder(
    BuildContext context,
  ) =>
      LoginViewModel();
}

```

--------------------------------

### Navigate with Custom Transition

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

When navigating to a view defined as a `CustomRoute`, you can specify a transition using the `transition` parameter in the `navigateTo` method.

```dart
await _navigationService.navigateTo(
  Routes.secondView,
  transition: TransitionsBuilders.fadeIn,
);

```

--------------------------------

### Integrate Generated Form Mixin and Sync Functionality

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Import the generated form file, mixin the generated class, and call syncFormWithViewModel in onViewModelReady. This enables automatic synchronization between the View and ViewModel.

```dart
import 'text_reverse_view.form.dart'; // 1. Import the generated file  
  
@FormView(fields: [  
  FormTextField(name: 'reverseInput'),  
])  
class TextReverseView extends StackedView<TextReverseViewModel>  
  with $TextReverseView { // 2. Mix in $TextReverseView Mixin  
  
  @override  
  Widget builder(  
    BuildContext context,  
    TextReverseViewModel viewModel,  
    Widget? child,  
  ) {  
    return Scaffold(  
      ...  
    );  
  }  
  
  @override  
  void onViewModelReady(TextReverseViewModel viewModel) {  
    syncFormWithViewModel(viewModel);  
  }  
  ...

```

--------------------------------

### IndexTrackingViewModel for Web Navigation

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Demonstrates using setCurrentWebPageIndex within a ViewModel that extends IndexTrackingViewModel to manage the current index based on the URL for web applications.

```dart
class BottomNavExampleViewModel extends IndexTrackingViewModel {  
  final _routerService = exampleLocator<RouterService>();  
  
  BottomNavExampleViewModel() {  
    setCurrentWebPageIndex(_routerService);  
  }  
}
```

--------------------------------

### Registering a Factory with Environment Filter

Source: https://stacked.filledstacks.com/docs/in-depth/service-locator

Register a service as a LazySingleton that is only available in a specific development environment. This ensures the service is only created when the application is run in the specified environment.

```dart
LazySingleton(
  classType: NavigationService,
  environments: {Environment.dev},
),
```

--------------------------------

### Service Implementation for ReactiveViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

A service using `ListenableServiceMixin` that listens to reactive values. `notifyListeners()` is called to trigger updates in listening ViewModels.

```dart
class PostService with ListenableServiceMixin {
  PostService() {
    listenToReactiveValues([_postCount]);
  }

  int _postCount = 0;
  int get postCount => _postCount;

  Future<void> increment() async {
    _postCount++;
    notifyListeners(); // ViewModels listening postCount value are notified and their View is rebuild
  }
}

```

--------------------------------

### Generate Form Code

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Run the Stacked generate command after defining your form fields. This command creates the necessary form-related files, including a mixin for controller management.

```bash
stacked generate  

```

--------------------------------

### Configure stacked_generator for Navigator 2.0

Source: https://stacked.filledstacks.com/docs/stacked-router/routing-basics

Create a build.yaml file to configure the stacked_generator to use the v2 navigator. This ensures that a StackedRouter is generated based on Flutter's V2 navigator, which is better suited for web URL navigation.

```yaml
targets:
  $default:
    builders:
      stacked_generator|stackedRouterGenerator:
        options:
          navigator2: true
```

--------------------------------

### Generate Code with Stacked CLI

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Use this command to generate code when manual changes have been made or a new model has been added. It serves as an alternative to running 'flutter pub run build_runner build --delete-conflicting-outputs'.

```bash
stacked generate
```

--------------------------------

### MultipleFutureViewModel Implementation

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Defines a ViewModel that fetches data from multiple futures concurrently. Use this when your UI needs to display data from several independent asynchronous sources. The futuresMap defines which futures to run and their keys.

```dart
import 'package:stacked/stacked.dart';  
  
const String _NumberDelayFuture = 'delayedNumber';  
const String _StringDelayFuture = 'delayedString';  
  
class MultipleFuturesExampleViewModel extends MultipleFutureViewModel {  
  int get fetchedNumber => dataMap[_NumberDelayFuture];  
  String get fetchedString => dataMap[_StringDelayFuture];  
  
  bool get fetchingNumber => busy(_NumberDelayFuture);  
  bool get fetchingString => busy(_StringDelayFuture);  
  
  @override  
  Map<String, Future Function()> get futuresMap => {  
        _NumberDelayFuture: getNumberAfterDelay,  
        _StringDelayFuture: getStringAfterDelay,  
      };  
  
  Future<int> getNumberAfterDelay() async {  
    await Future.delayed(Duration(seconds: 2));  
    return 3;  
  }  
  
  Future<String> getStringAfterDelay() async {  
    await Future.delayed(Duration(seconds: 3));  
    return 'String data';  
  }  
}
```

--------------------------------

### runBusyFuture with Custom Busy Object Key

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Use runBusyFuture with a specific 'busyObject' key to manage busy states for individual items or distinct operations within a ViewModel. This allows for granular UI updates.

```dart
const String BusyObjectKey = 'my-busy-key';

class BusyExampleViewModel extends BaseViewModel {
  Future longUpdateStuff() async {
    // Sets busy to true before starting future and sets it to false after executing
    // You can also pass in an object as the busy object. Otherwise it'll use the ViewModel
    var result = await runBusyFuture(updateStuff(), busyObject: BusyObjectKey);
  }

  Future updateStuff() {
    return Future.delayed(const Duration(seconds: 3));
  }
}
```

--------------------------------

### Register Service Mock Spec

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this comment to `test_helpers.dart` to indicate where a new mock specification should be added.

```dart
// @stacked-mock-spec  
```

--------------------------------

### Register Service Dependency

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this comment to `lib/app/app.dart` to indicate where a new service dependency should be registered.

```dart
// @stacked-service  
```

--------------------------------

### Navigate Back with Result

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Navigates back to the previous view and passes a result object to the calling function. The navigation call can be awaited.

```dart
final result = await _navigationService.replaceWithHomeView(startingIndex: 0);
print('Returned result: $result');

```

```dart
_navigationService.back(result: 'From back call');

```

--------------------------------

### Use Logger in a ViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/logger

Instantiate and use the logger within your ViewModel to log messages. The logger automatically captures the function name.

```dart
class MyViewModel {
  final logger = getLogger('MyViewModel');

  void doStuff() {
    logger.i('');
  }
}

```

--------------------------------

### TextFormField with Controller

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

A simple TextFormField that uses a controller managed by Stacked's form system.

```dart
TextFormField(controller: reverseInputController),

```

--------------------------------

### runBusyFuture for Automatic Busy State Handling

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Utilize runBusyFuture to automatically manage the ViewModel's busy state during asynchronous operations. This simplifies the process of indicating activity to the UI.

```dart
class BusyExampleViewModel extends BaseViewModel {
 Future longUpdateStuff() async {
    // Sets busy to true before starting future and sets it to false after executing
    // You can also pass in an object as the busy object. Otherwise it'll use the ViewModel
    var result = await runBusyFuture(updateStuff());
  }

  Future updateStuff() {
    return Future.delayed(const Duration(seconds: 3));
  }
}
```

--------------------------------

### Add Logger Dependency

Source: https://stacked.filledstacks.com/docs/in-depth/logger

Include the logger package in your pubspec.yaml file to use its functionalities.

```yaml
dependencies:
  ...
  logger:

```

--------------------------------

### Add Form Functionality to Existing ViewModel

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Mix the FormStateHelper into a ViewModel that already extends FutureViewModel or StreamViewModel to add form capabilities.

```dart
// Original class that you want to add form functionality to
class ContentViewModel extends FutureViewModel<Posts> {
  ...
}

// Do instead
class ContentViewModel extends FutureViewModel<Posts> with FormStateHelper implements FormViewModel {
  ...
}
```

--------------------------------

### Register Dialog Dependency

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this comment to `lib/app/app.dart` within the `dialogs` property of `StackedApp` to indicate where a new dialog dependency should be registered.

```dart
// @stacked-dialog  
```

--------------------------------

### Define Form Fields with @FormView Annotation

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Annotate your View class with @FormView to define the fields for your form. This tells Stacked which controllers to generate.

```dart
import 'package:stacked/stacked_annotations.dart';  
  
@FormView(fields: [  
  FormTextField(name: 'reverseInput'),  
])  
class TextReverseView extends StackedView<TextReverseViewModel> {  
  const TextReverseView({Key? key}) : super(key: key);  
  ...

```

--------------------------------

### Registering Dependencies in StackedApp

Source: https://stacked.filledstacks.com/docs/in-depth/service-locator

Register various types of dependencies like Singletons, LazySingletons, and Factories within the StackedApp annotation using the 'dependencies' property. This sets up the service locator with your application's components.

```dart
@StackedApp(
  dependencies: [
    Singleton(classType: NavigationService),
    LazySingleton(classType: ThemeService, resolveUsing: ThemeService.getInstance),
    LazySingleton(classType: FirebaseAuthService, asType: AuthService),
    InitializableSingleton(classType: SharedPreferencesService),
    Factory(classType: FactoryService),
  ],
)

```

--------------------------------

### Stacked CLI Import Template Identifier

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this template identifier to your lib/app/app.dart file under the last import to indicate where Stacked CLI should add new imports when creating components like views.

```dart
// @stacked-import  
```

--------------------------------

### Stacked CLI Route Template Identifier

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Place this template identifier in your lib/app/app.dart file underneath your last route definition. Stacked CLI will use this to automatically add new routes when creating views.

```dart
// @stacked-route  
```

--------------------------------

### Counter View Structure

Source: https://stacked.filledstacks.com/docs/getting-started/how-it-works

Define a Flutter View by extending StackedView and implementing the builder and viewModelBuilder methods.

```dart
class CounterView extends StackedView<CounterViewModel> {
  
  @override
  // A builder function that gives us a ViewModel
  Widget builder(
    BuildContext context,
    CounterViewModel viewModel,
    Widget? child,
    ) {
    return Scaffold(
      ...
    );
  }
  
  @override
  CounterViewModel viewModelBuilder(BuildContext context) => CounterViewModel();
}

```

--------------------------------

### Add a New Bottom Sheet

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Create a new BottomSheet, its associated Model, and tests. The command also registers the BottomSheet in app.dart. Use --no-model to create a BottomSheet without a model.

```bash
stacked create bottom_sheet alert  
```

--------------------------------

### Configure HomeView Background

Source: https://stacked.filledstacks.com/docs/getting-started/startup-logic

Sets the background color of the HomeView to purple. This view is navigated to if the user is logged in.

```dart
class HomeView extends StackedView<HomeViewModel> {
  const HomeView({Key? key}) : super(key: key);

  @override
  Widget builder(
    BuildContext context,
    HomeViewModel viewModel,
    Widget? child,
  ) {
    return Scaffold(
      backgroundColor: Colors.purple,
      body: Container(
        padding: const EdgeInsets.only(left: 25.0, right: 25.0),
      ),
    );
  }

  @override
  HomeViewModel viewModelBuilder(
    BuildContext context,
  ) =>
      HomeViewModel();
}

```

--------------------------------

### Register BottomSheet Dependency

Source: https://stacked.filledstacks.com/docs/tooling/stacked-cli

Add this comment to `lib/app/app.dart` within the `bottomsheets` property of `StackedApp` to indicate where a new bottom sheet dependency should be registered.

```dart
// @stacked-bottom-sheet  
```

--------------------------------

### Specify Transition Builder for Custom Route

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Assign a static builder function from `TransitionsBuilders` to the `transitionsBuilder` property of `CustomRoute` to apply a pre-defined transition like `fadeIn`.

```dart
@StackedApp(routes: [
  ...
  CustomRoute(
    page: CounterView,
    transitionsBuilder: TransitionsBuilders.fadeIn,
  ),
  // @stacked-route
])
class App {}

```

--------------------------------

### TextReverseView Builder Widget

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

This code defines the UI for the Text Reverser view, including input fields, validation messages, and the reversed text display. It utilizes Stacked's form management for controllers.

```dart
@override
  Widget builder(
    BuildContext context,
    TextReverseViewModel viewModel,
    Widget? child,
  ) {
    return Scaffold(
      appBar: AppBar(title: const Text('Text Reverser')),
      body: Container(
        padding: const EdgeInsets.only(left: 25.0, right: 25.0),
        child: SingleChildScrollView(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              verticalSpaceMedium,
              const Text(
                'Text to Reverse',
                style: TextStyle(fontSize: 18, fontWeight: FontWeight.w700),
              ),
              verticalSpaceSmall,
              TextFormField(controller: reverseInputController),
              if (viewModel.hasReverseInputValidationMessage) ...[
                verticalSpaceTiny,
                Text(
                  viewModel.reverseInputValidationMessage!,
                  style: const TextStyle(
                    color: Colors.red,
                    fontSize: 12,
                    fontWeight: FontWeight.w700,
                  ),
                ),
              ],
              verticalSpaceMedium,
              Text(
                viewModel.reversedText,
                style: const TextStyle(
                  fontSize: 18,
                  fontWeight: FontWeight.w700,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

```

--------------------------------

### Display Counter and Increment on FAB Tap

Source: https://stacked.filledstacks.com/docs/getting-started/how-it-works

Update the CounterView's builder to display the counter value and trigger the incrementCounter function when the FloatingActionButton is pressed.

```dart
@override
Widget builder(BuildContext context, CounterViewModel viewModel, Widget? child) {
  return Scaffold(
    floatingActionButton:  
      FloatingActionButton(onPressed: viewModel.incrementCounter),
    body: Center(
      child: Text(
        viewModel.counter.toString(),
        style: const TextStyle(
          fontSize: 30,
          fontWeight: FontWeight.bold,
        ),
      ),
    ),
  );
}

```

--------------------------------

### Custom Logger Function Name

Source: https://stacked.filledstacks.com/docs/in-depth/logger

Customize the name of the logger retrieval function if 'getLogger' conflicts with existing code. This is done via the logHelperName property in the StackedApp configuration.

```dart
@StackedApp(
logger: StackedLogger(
    logHelperName: 'getStackedLogger',
  )
)

```

--------------------------------

### StackedView UI Integration with ViewModel State

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Integrate a StackedView with its ViewModel to react to busy states and trigger ViewModel actions. Use viewModel.isBusy and viewModel.busy(object) to conditionally render UI elements.

```dart
class WidgetOneView extends StackedView<WidgetOneViewModel> {
  const WidgetOneView({Key? key}) : super(key: key);

  @override
  Widget builder(
    BuildContext context,
    WidgetOneViewModel viewModel,
    Widget? child,
  ) {
    return GestureDetector(
        onTap: () => viewModel.longUpdateStuff(),
        child: Container(
          width: 100,
          height: 100,
          // Use isBusy to check if the ViewModel is set to busy
          color: viewModel.isBusy ? Colors.green : Colors.red,
          alignment: Alignment.center,
          // A bit silly to pass the same property back into the ViewModel
          // but here it makes sense
          child: viewModel.busy(viewModel.currentHuman)
              ? Center(
                  child: CircularProgressIndicator(),
                )
              : Container(/* Human Details styling */)
        ),
      ),
    );
  }
}
```

--------------------------------

### Define a FutureViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Extend FutureViewModel and override the futureToRun getter to provide the Future that fetches data. The ViewModel automatically manages the busy state and data availability.

```dart
class FutureExampleViewModel extends FutureViewModel<String> {
  @override
  Future<String> futureToRun() => getDataFromServer();
  
  Future<String> getDataFromServer() async {
    await Future.delayed(const Duration(seconds: 3));
    return 'This is fetched from everywhere';
  }
}
```

--------------------------------

### Define Custom Route at App Level

Source: https://stacked.filledstacks.com/docs/getting-started/navigation-basics

Use `CustomRoute` in your `app.dart` to specify a custom transition for a specific view. This ensures all navigations to that view will use the defined transition.

```dart
@StackedApp(routes: [
  MaterialRoute(page: StartupView),
  MaterialRoute(page: HomeView),
  CustomRoute(page: CounterView), // <== Custom Route
  // @stacked-route
])
class App {}

```

--------------------------------

### Extend ViewModel with FormViewModel

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Update your ViewModel to extend from FormViewModel instead of BaseViewModel. This provides the necessary base functionality for managing form data.

```dart
class TextReverseViewModel extends FormViewModel {  
  ...

```

--------------------------------

### Displaying Error State from FutureViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

In your View, use the viewModel.hasError property to conditionally render an error message or fallback UI. This allows users to be informed when data fetching fails.

```dart
class FutureExampleView extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ViewModelBuilder<FutureExampleViewModel>.reactive(
      builder: (context, viewModel, child) => Scaffold(
        body: viewModel.hasError  
            ? Container(  
                color: Colors.red,
                alignment: Alignment.center,
                child: Text(
                  'An error has occered while running the future',
                  style: TextStyle(color: Colors.white),
                ),
              )
            : Center(
                child: viewModel.isBusy  
                    ? CircularProgressIndicator()
                    : Text(viewModel.data),
              ),
      ),
      viewModelBuilder: () => FutureExampleViewModel(),
    );
  }
}
```

--------------------------------

### TextReverseViewModel with Reversed Text Property

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Defines the ViewModel for the TextReverseView. It includes a computed property 'reversedText' that reverses the input from the 'reverseInput' field.

```dart
import 'package:stacked/stacked.dart';
import 'text_reverse_view.form.dart';

class TextReverseViewModel extends FormViewModel {
  String get reversedText =>
    hasReverseInput ? reverseInputValue!.split('').reversed.join('') : '----';
}

```

--------------------------------

### Dispose Form Controllers in ViewModel

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Overrides the onDispose function in the View to ensure form controllers are properly disposed of by calling the generated disposeForm() function.

```dart
@override
  void onDispose(TextReverseViewModel viewModel) {
    super.onDispose(viewModel);
    disposeForm();
  }

```

--------------------------------

### Handling Errors in FutureViewModel

Source: https://stacked.filledstacks.com/docs/in-depth/viewmodels

Override the future getter and the onError function to handle errors during Future execution. The ViewModel exposes a hasError property to indicate if an error occurred.

```dart
class FutureExampleViewModel extends FutureViewModel<String> {
  @override
  Future<String> get future => getDataFromServer();
  
  Future<String> getDataFromServer() async {
    await Future.delayed(const Duration(seconds: 3));
    throw Exception('This is an error');
  }
  
  @override
  void onError(error) {
  }
}
```

--------------------------------

### Apply Validator to FormTextField

Source: https://stacked.filledstacks.com/docs/getting-started/form-basics

Assign the custom validator function to the 'validator' property of the FormTextField annotation.

```dart
@FormView(
  fields: [
    FormTextField(
      name: 'reverseInput',
      validator: TextReverseValidators.validateReverseText,
    ),
  ],
)
...
```

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