update states_rebuilder sample to use the latest version and to use immutable state

states_rebuilder/README.md

@@ -46,37 +46,88 @@ Contains service application use cases business logic. It defines a set of API t
 
 1. With states_rebuilder you can achieve a clear separation between UI and business logic;
 2. Your business logic is made up of pure dart classes without the need to refer to external packages or frameworks (NO extension, NO notification, NO annotation);
-```dart
-class Foo {
- //Vanilla dart class
- //NO inheritance form external libraries
- //NO notification
- //No annotation
-}
-```
-3. You make a singleton of your logical class available to the widget tree by injecting it using the Injector widget.
-```dart
-Injector(
- inject : [Inject(()=>Foo())]
- builder : (context) => MyChildWidget()
-)
-```
-Injector is a StatefulWidget. It can be used any where in the widget tree. 
-4. From any child widget of the Injector widget, you can get the registered raw singleton using the static method `Injector.get<T>()` method;
-```dart
-final Foo foo = Injector.get<Foo>();
-```
-5. To get the registered singleton wrapped with a reactive environment, you use the static method 
-`Injector.getAsReactive<T>()` method:
-```dart
-final ReactiveModel<Foo> foo = Injector.getAsReactive<Foo>();
-```
-In fact, for each injected model, states_rebuilder registers two singletons:
-- The raw singleton of the model
-- The reactive singleton of the model which is the raw singleton wrapped with a reactive environment:
-The reactive environment adds getters, fields, and methods to modify the state, track the state of the reactive environment and notify the widgets which are subscribed to it.
-6. To subscribe a widget as observer, we use `StateBuilder` widget or define the context parameter in `Injector.getAsReactive<Foo>(context:context)`.
-7. The `setState` method is where actions that mutate the state and send notifications are defined.
-What happens is that from the user interface, we use the `setState` method to mutate the state and notify subscribed widgets after the state mutation. In the `setState`, we can define a callback for all the side effects to be executed after the state change and just before rebuilding subscribed widgets using `onSetState`, `onData` and `onError` parameter(or `onRebuild` so that the code executes after the reconstruction). From inside `onSetState`, we can call another `setState` to mutate the state and notify the user interface with another call `onSetState` (`onRebuild`) and so on …
-
-For more information and tutorials on how states_rebuilder work please check out the [official documentation](https://github.com/GIfatahTH/states_rebuilder).
+3. With states_rebuilder you can manage immutable as well as mutable state.
+
+In this demo implementation, I choose to use immutable state, you can find the same app implemented with mutable state in the example folder of the [official repo in github](https://github.com/GIfatahTH/states_rebuilder).
+
+In this implementation, I add the requirement that when a todo is added, deleted or updated, it will be instantly displayed in the user interface, so that the user will not notice any delay, and the async method `saveTodo` will be called in the background to persist the change. If the `saveTodo` method fails, the old state is returned and displayed back with a` SnackBar` containing the error message.
+
+The idea is simple:
+1- Write your immutable `TodosState` class using pure dart without any use of external libraries.
+  ```dart
+    @immutable
+    class TodosState {
+      TodosState({
+        ITodosRepository todoRepository,
+        List<Todo> todos,
+        VisibilityFilter activeFilter,
+      })  : _todoRepository = todoRepository,
+            _todos = todos,
+            _activeFilter = activeFilter;
+
+    //....
+    }
+  ```
+2- Inject the `TodosState` using the `Injector` widget,
+  ```dart
+    return Injector(
+    inject: [
+      Inject(
+        () => TodosState(
+          todos: [],
+          activeFilter: VisibilityFilter.all,
+          todoRepository: repository,
+        ),
+      )
+    ],
+  ```
+3- use one of the available observer widgets offered by states_rebuilder to subscribed to the `TodosState` `ReactiveModel`.
+  ```dart
+       return StateBuilder<TodosState>(
+          observe: () => RM.get<TodosState>(),
+          builder: (context, todosStoreRM) {
+              //...
+
+          }
+      )  
+  ```
+4- to notify the observing widgets use: 
+  * for sync method: use `setValue` method or the `value` setter.
+    ```dart
+    onSelected: (filter) {
+
+      activeFilterRM.setValue(
+        () => filter,
+        onData: (context, data) {
+          RM.get<TodosState>().value =
+              RM.get<TodosState>().value.copyWith(activeFilter: filter);
+        },
+      );
+    ```
+  * for async future method: use future method.
+  ```dart
+        body: WhenRebuilderOr<AppTab>(
+        observeMany: [
+            () => RM.get<TodosState>().asNew(HomeScreen)
+                      ..future((t) => t.loadTodos())
+                      .onError(ErrorHandler.showErrorDialog),
+            () => _activeTabRMKey,
+        ]
+
+        //...
+      )  
+  ```
+  * for async stream method: use stream method.
+    ```dart
+        onSelected: (action) {
+
+          RM.get<TodosState>()
+            .stream(
+                (action == ExtraAction.toggleAllComplete)
+                    ? (t) => t.toggleAll()
+                    : (t) => t.clearCompleted(),
+              )
+            .onError(ErrorHandler.showErrorSnackBar);
+        }
+    ```
+

states_rebuilder/android/settings_aar.gradle

@@ -0,0 +1 @@
+include ':app'

states_rebuilder/lib/app.dart

@@ -1,23 +1,38 @@
 import 'package:flutter/material.dart';
 import 'package:states_rebuilder/states_rebuilder.dart';
 import 'package:todos_app_core/todos_app_core.dart';
-import 'data_source/todo_repository.dart';
+
 import 'localization.dart';
-import 'service/todos_service.dart';
+import 'service/common/enums.dart';
+import 'service/interfaces/i_todo_repository.dart';
+import 'service/todos_state.dart';
 import 'ui/pages/add_edit_screen.dart/add_edit_screen.dart';
 import 'ui/pages/home_screen/home_screen.dart';
 
 class StatesRebuilderApp extends StatelessWidget {
-  final StatesBuilderTodosRepository repository;
+  final ITodosRepository repository;
 
   const StatesRebuilderApp({Key key, this.repository}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
-    //Injecting the TodoService globally before MaterialApp widget.
+    ////uncomment this line to consol log and see the notification timeline
+    //RM.printActiveRM = true;
+
+    //
+    //Injecting the TodosState globally before MaterialApp widget.
     //It will be available throughout all the widget tree even after navigation.
+    //The initial state is an empty todos and VisibilityFilter.all
     return Injector(
-      inject: [Inject(() => TodosService(repository))],
+      inject: [
+        Inject(
+          () => TodosState(
+            todos: [],
+            activeFilter: VisibilityFilter.all,
+            todoRepository: repository,
+          ),
+        )
+      ],
       builder: (_) => MaterialApp(
         title: StatesRebuilderLocalizations().appTitle,
         theme: ArchSampleTheme.theme,

states_rebuilder/lib/data_source/todo_repository.dart

@@ -4,10 +4,10 @@ import '../domain/entities/todo.dart';
 import '../service/exceptions/persistance_exception.dart';
 import '../service/interfaces/i_todo_repository.dart';
 
-class StatesBuilderTodosRepository implements ITodosRepository {
+class StatesRebuilderTodosRepository implements ITodosRepository {
   final core.TodosRepository _todosRepository;
 
-  StatesBuilderTodosRepository({core.TodosRepository todosRepository})
+  StatesRebuilderTodosRepository({core.TodosRepository todosRepository})
       : _todosRepository = todosRepository;
 
   @override
@@ -27,16 +27,18 @@ class StatesBuilderTodosRepository implements ITodosRepository {
   }
 
   @override
-  Future saveTodos(List<Todo> todos) {
+  Future saveTodos(List<Todo> todos) async {
     try {
       var todosEntities = <TodoEntity>[];
+      //// to simulate en error uncomment these lines.
+      // await Future.delayed(Duration(milliseconds: 500));
+      // throw Exception();
       for (var todo in todos) {
         todosEntities.add(TodoEntity.fromJson(todo.toJson()));
       }
-
       return _todosRepository.saveTodos(todosEntities);
     } catch (e) {
-      throw PersistanceException('There is a problem in saving todos : $e');
+      throw PersistanceException('There is a problem in saving todos');
     }
   }
 }

states_rebuilder/lib/domain/entities/todo.dart

@@ -1,23 +1,25 @@
+import 'package:flutter/cupertino.dart';
 import 'package:todos_app_core/todos_app_core.dart' as flutter_arch_sample_app;
 
 import '../exceptions/validation_exception.dart';
 
-//Entity is a mutable object with an ID. It should contain all the logic It controls.
-//Entity is validated just before persistance, ie, in toMap() method.
+@immutable
 class Todo {
-  String id;
-  bool complete;
-  String note;
-  String task;
+  final String id;
+  final bool complete;
+  final String note;
+  final String task;
 
   Todo(this.task, {String id, this.note, this.complete = false})
       : id = id ?? flutter_arch_sample_app.Uuid().generateV4();
 
-  Todo.fromJson(Map<String, Object> map) {
-    id = map['id'] as String;
-    task = map['task'] as String;
-    note = map['note'] as String;
-    complete = map['complete'] as bool;
+  factory Todo.fromJson(Map<String, Object> map) {
+    return Todo(
+      map['task'] as String,
+      id: map['id'] as String,
+      note: map['note'] as String,
+      complete: map['complete'] as bool,
+    );
   }
 
   // toJson is called just before persistance.
@@ -41,11 +43,38 @@ class Todo {
     }
   }
 
+  Todo copyWith({
+    String task,
+    String note,
+    bool complete,
+    String id,
+  }) {
+    return Todo(
+      task ?? this.task,
+      id: id ?? this.id,
+      note: note ?? this.note,
+      complete: complete ?? this.complete,
+    );
+  }
+
+  @override
+  bool operator ==(Object o) {
+    if (identical(this, o)) return true;
+
+    return o is Todo &&
+        o.id == id &&
+        o.complete == complete &&
+        o.note == note &&
+        o.task == task;
+  }
+
   @override
-  int get hashCode => id.hashCode;
+  int get hashCode {
+    return id.hashCode ^ complete.hashCode ^ note.hashCode ^ task.hashCode;
+  }
 
   @override
-  bool operator ==(Object other) =>
-      identical(this, other) ||
-      other is Todo && runtimeType == other.runtimeType && id == other.id;
+  String toString() {
+    return 'Todo(id: $id,task:$task, complete: $complete)';
+  }
 }

states_rebuilder/lib/domain/exceptions/validation_exception.dart

@@ -2,4 +2,8 @@ class ValidationException extends Error {
   final String message;
 
   ValidationException(this.message);
+  @override
+  String toString() {
+    return message;
+  }
 }

states_rebuilder/lib/main.dart

@@ -12,10 +12,9 @@ import 'data_source/todo_repository.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
-
   runApp(
     StatesRebuilderApp(
-      repository: StatesBuilderTodosRepository(
+      repository: StatesRebuilderTodosRepository(
         todosRepository: LocalStorageRepository(
           localStorage: KeyValueStorage(
             'states_rebuilder',

states_rebuilder/lib/main_web.dart

@@ -15,7 +15,7 @@ void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   runApp(
     StatesRebuilderApp(
-      repository: StatesBuilderTodosRepository(
+      repository: StatesRebuilderTodosRepository(
         todosRepository: LocalStorageRepository(
           localStorage: KeyValueStorage(
             'states_rebuilder',

states_rebuilder/lib/service/exceptions/persistance_exception.dart

@@ -1,5 +1,8 @@
 class PersistanceException extends Error {
   final String message;
-
   PersistanceException(this.message);
+  @override
+  String toString() {
+    return message.toString();
+  }
 }