Structure


Flutter Control is complex library to maintain App and State management.
Helps to separate Business Logic from UI and with Communication, Localization, Routing and passing arguments/values/events around.


Simplified structure of core classes in Flutter Control. Full diagram is at bottom of this page.. Structure


Flutter Control Core

  • ControlBase Wraps App and initializes Control, Factory, Localization, Injector and Broadcaster. It's just shortcut to start with Flutter Control.
  • ControlFactory Initializes and can store Controllers, Models and other objects. Dependency Injection is provided during object initialization and also on demand.
    Factory has own Storage. Objects in this storage are accessible via custom key or Type. Best practice is to use type as a key..
    Comes with ControlProvider a class to easily access core functions from any part of App. Provider has two parts - Static and Widget. With static part is possible to 'get', 'set', 'init' and 'inject' objects. Widget part is StatelessWidget that provides object from Factory.
    Factory is one and only singleton in this library.
    Core objects of Flutter Control are stored in Factory Storage by default and are accessible by their Type or via Providers.
    ControlBase(
      locales: {
        'en': AssetPath().localization('en'),
      },
      entries: {
        CounterController: CounterController(),
      },
      initializers: {
        Counter: (_) => CounterModel(),
      },
      injector: Injector.of({
        Counter: (item, args) => item.controller = ControlProvider.get('counter'),
      }),
      loader: (context) => LoadingPage(),
      root: (context) => CounterPage(),
      app: (context, key, home) {
        return MaterialApp(
          key: key,
          home: home,
          title: 'Flutter Control Example',
        );
      },
    );

  • BaseControlModel is base class to maintain Business Logic parts of App.
    BaseController is extended version of BaseControlModel with more functionality. Mainly used for pages or complex Widgets and also to separate robust Logic parts.
    BaseModel is extended but lightweight version of BaseControlModel. Mainly used for Items in dynamic List or to separate/reuse Logic parts.
    This Controllers comes with few mixin classes to extend base functionality:

    • RouteController to provide navigation outside of Widget.
    • StateController to notify state of whole Widget.
  • ControlWidget is base abstract class (StatefulWidget) to maintain UI parts of App. Widget is created with default ControlState to correctly reflect lifecycle of Widget to Models and Controllers. So there is no need to create custom State.
    If used correctly, this Widget will Init all containing Controllers and pass arguments to these Controllers.
    This Widget comes with few mixin classes:

    • RouteControl to abstract navigation and easily pass arguments and init other Pages.
    • TickerControl and SingleTickerControl to create State with Ticker and provide access to vsync.

    SingleControlWidget is used to work with one Controller. This controller can be passed through constructor/init args or grabbed from ControlFactory.
    BaseControlWidget is used when there is no need to construct Controllers. Controllers still can be passed through constructor or init args.

class CounterModel extends BaseModel with StateController {
  int count = 0;

  void increase() {
    count++;
    notifyState();
  }
}

class CounterPage extends SingleControlWidget<CounterModel> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text(controller.count.toString()),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: controller.increase,
        child: Text('+'),
      ),
    );
  }
}

After hitting '+' button State of CounterPage will be notified and whole Widget is re-build.


  • ActionControl is one type of Observable used in this Library. It's quite lightweight and is used to notify Widgets and to provide events about value changes.
    Has three variants - Single (just one listener), Broadcast (multiple listeners) and Broadcast Listener (subscribes to Global Broadcaster).
    On the Widget side is ControlBuilder to dynamically build Widgets. It's also possible to use ControlBuilderGroup for multiple Observables.
    Value is set directly, but can be used privately and with ActionControlSub interface provide subscription functionality to public.
    Upon dismiss every ControlSubscription is closed.

  • FieldControl is more robust Observable solution around Stream and StreamController. Primarily is used to notify Widgets and to provide events about value changes.
    Can listen Stream, Future or subscribe to another FieldControl with possibility to filter and convert values.
    FieldControl comes with pre-build primitive variants as StringControl, DoubleControl, etc., where is possible to use validation, regex or value clamping. And also ListControl to work with Iterables.
    On the Widget side is FieldBuilder and FieldStreamBuilder to dynamically build Widgets. Also FieldBuilderGroup for use with multiple Observables.
    It's possible to set value directly, via FieldSink or FieldSinkConverter.
    Upon dismiss every FieldSubscription is closed.

class CounterController extends BaseController {
  final count = IntegerControl();

  void increase() => count.value++;

  @override
  void dispose() {
    super.dispose();
    count.dispose();
  }
}

class CounterPage extends SingleControlWidget<CounterController> {

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: FieldBuilder<int>(
            controller: controller.count,
            builder: (context, value) {
              return Text(value.toString());
            }),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: controller.increase,
        child: Text('+'),
      ),
    );
  }
}

After hitting '+' button State of FieldBuilder will be notified and only Text Widget is re-build.


There is more ways how to pass and init Controllers in ControlWidget and listen about State lifecycle.

  1. Constructor: we can pass Controllers as arguments with other args.
  CounterPage({Key key, CounterController controller, int defaultValue: 10}): super(key: key, args:[controller, defaultValue]);
  1. Lazy load: Construct them manually or from Factory by overriding initControllers.

  final controller = SuperController();

  @override
  List<BaseControlModel> initControllers() {
    return [
      controller,
      CounterController(),
      ControlProvider.get<CounterModel>(),
    ];
  }
  1. Pass them via Initializable interface. This method is same as Constructor args. Both methods can be combined with different arguments.
    init is also called by RouteControl, when passing arguments from one page to another.
  init(Map args);
  1. On demand during build statically or via Provider Widget, and new args can be pushed to objects:
  @override
  Widget build(BuildContext context) {
    final controller = ControlProvider.get(CounterController, {'msg': 'static invoke'});
    
    return ControlProvider<CounterController>(
      args: 10,
      builder: (context, value) => Center(
        child: Text((controller == value).toString()),
      ),
    );
  }

Arguments are then passed into Controllers as a Map. So you need to know 'key' or 'Type' to retrieve them. Static class Parse and their extensions can help..

  @override
  void onInit(Map args) {
    int count = args.getArg<int>(defaultValue: -1);
    String message = Parse.getArg<String>(args, key: 'msg', defaultValue: 'no message');
  }

BaseController by default prevents 'multi init'. But this behaviour can be of course overridden.


Other Important classes

  • BaseLocalization Json based localization, that supports simple strings, plurals and dynamic structures.
    Easy access via LocalizationProvider mixin. Localization object is stored in Factory, so is accessible without context and can be used even in Controllers, Entities, etc.
    Localization is initialized and loaded in ControlBase by default.
    And by default ControlWidget uses this localization.
  class HelloControl extends BaseControlWidget {
    @override
    Widget build(BuildContext context) {
      return Text(localize('hello_world'));
    }
  }
  
  class HelloText extends StatelessWidget with LocalizationProvider {
    @override
    Widget build(BuildContext context) {
      return Text(localize('hello_world'));
    }
  }
  • ControlBroadcast Event stream across whole App. Broadcaster is part of ControlFactory and is stored there.
    With BroadcastProvider is possible to subscribe to any stream and send data or events from one end of App to another, even to Widgets.
  BroadcastProvider.subscribe<BasketItem>(BasketAdd, (item) => addToBasket(item));
  
  BroadcastBuilder<BasketItem>(
    key: BasketAdd,
    builder: (context, item) => Text(
      'New item added to basket: ${item.name}',
    ),
  );
  
  BroadcatProvider.broadcast(BasketAdd, BasketItem(name: 'socks'));
  • ControlTheme wraps ThemeData, MediaQuery into Device class and AssetPath.
    Theme is cached on their first use, so 'Theme.of' is called just once per Widget.
    Control Theme adds some parameters and getters on top of standard Theme.
    Easy access via ThemeProvider a mixin class that initializes ControlTheme.
    Custom ControlTheme class builder can be used in ControlBase constructor to modify default params and provide more of them.
  class HelloControl extends BaseControlWidget with ThemeProvider<MyTheme> {
    @override
    Widget build(BuildContext context) {
      return Padding(
        padding: EdgeInsets.all(theme.padding),
        child: Text(
          localize('hello_world'),
          style: fontPrimary.title,
        ),
      );
    }
  }

  • PageRouteProvider Specifies Route and WidgetBuilder settings for RouteHandler. With WidgetInitializer passing args to Widgets and Controllers during navigation.
    Use RouteControl mixin to enable this navigation in Widget.
  PageRouteProvider get counterPageRoute => PageRouteProvider.of(
        identifier: 'counter',
        builder: (context) => CounterPage(),
      );
  class HelloPage extends BaseControlWidget with RouteControl {
  
    @override
    Widget build(BuildContext context) {
      return FlatButton(
        onPressed: () => counterPageRoute.navigator(this).openRoute(),
        child: Text(
          'open counter page',
        ),
      );
    }
  }

Sometimes is handy to navigate from Controller or Model and for these scenarios exists RouteController mixin.
Widget still needs to be implemented with RouteControl.

  class HelloController extends BaseController with RouteController {
    
    void navigateToNextPage() => openPage(counterPageRoute);
  }
  
  class HelloPage extends SingleControlWidget<HelloController> with RouteControl {
  
    HelloController initController() => HelloController();
  
    @override
    Widget build(BuildContext context) {
      return FlatButton(
        onPressed: controller.navigateToNextPage,
        child: Text(
          'open counter page',
        ),
      );
    }
  }

Other classes

  • InputField Wrapper of TextField to provide more functionality and control via InputController.

  • DisposeHandler - mixin for any class, helps with object disposing.

  • PrefsProvider - mixin for any class, helps to store user preferences.

  • FutureBlock Retriggerable delay.

  • DelayBlock Delay to wrap a block of code to prevent 'super fast' completion and UI jiggles.

  • Parse Helps to parse json primitives and Iterables. Also helps to look up Lists and Maps for objects.

  • WidgetInitializer Helps to initialize Widgets with init data.

  • UnitId Unique Id generator based on Time, Index or just Random.

  • and more..


Full Core Structure

Structure

Libraries

flutter_control