Get Modular

Read this in other languages: English, Brazilian Portuguese. A flutter_modular fork To support Get natively.

What is Flutter Modular?

When a project is getting bigger and more complex, we unfortunately end up joining a lot of archives in just one, it makes harder the code maintenance and reusability too. The Modular give us a bunch of adapted solutions for Flutter, such a dependency injection, routes controller and a "Disposable Singletons" System(When a code provider call automatically dispose and clear the injection). The Modular came up prepared for adapt to any state management approach to its smart injection system, managing the memory use of your application.

What is Get?

Get is a Flutter route manager that is capable of navigating routes, showing snackbars and opening dialogs/bottomsheets from anywhere in the code without needing context. Get also has considerable performance improvements compared to the standard route.

Modular Structure

Modular gives us a structure that allows us to manage dependency injection and routes in just one file per module, so we can organize our files with that in mind. When all pages, controllers, blocs (and so on) are in a folder and recognized by this main file, we call this a module, as it will provide us with easy maintainability and especially the TOTAL decoupling of code for reuse in other projects.

Modular Pillars

Here are our main focuses with this package.

  • Automatic Memory Management.
  • Dependency Injection.
  • Dynamic Routes Control.
  • Modularization of Code.

Example

Getting started with Modular

Installation

Open pubspec.yaml of your Project and type:

dependencies:
    get_modular:

or install directly from Git to try out new features and fixes:

dependencies:
    get_modular:
        git:
            url: https://github.com/jonataslaw/modular

Using in a New Project

You need to do some initial setup.

Create a file to be your main widget, thinking of configuring named routes within MaterialApp: (app_widget.dart)

import 'package:flutter/material.dart';
import 'package:get_modular/get_modular.dart';

class AppWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      navigatorKey: Modular.navigatorKey,
      initialRoute: "/",
      // add Modular to manage the routing system
      onGenerateRoute: Modular.generateRoute,
    );
  }
}

Create a file to be your main module: (app_module.dart)

// extends from MainModule
class AppModule extends MainModule {

  // here will be any class you want to inject into your project (eg bloc, dependency)
  @override
  List<Bind> get binds => [];

  // here will be the routes of your module or you can navigate by Get.
  @override
  List<Router> get routers => [];

// add your main widget here
  @override
  Widget get bootstrap => AppWidget();
}

Finish the configuration in your main.dart file to start Modular.

import 'package:example/app/app_module.dart';
import 'package:flutter/material.dart';
import 'package:get_modular/get_modular.dart';

void main() => runApp(ModularApp(module: AppModule()));

Ready! Your app is already set to Modular!

Adding Routes

You can add routes to your module using the getter 'routers';

class AppModule extends MainModule {

 // here will be any class you want to inject into your project (eg bloc, dependency)
  @override
  List<Bind> get binds => [];

 // here will be the routes of your module
  @override
  List<Router> get routers => [
      Router("/", child: (_, args) => HomePage()),
      Router("/login", child: (_, args) => LoginPage()),
  ];

  // add your main widget here  
  @override
  Widget get bootstrap => AppWidget();
}

To navigate to a new screen, you can either navigate directly through the widget, or use named routes.

Get.to(NextScreen());
//or
Get.toNamed('/login');

To return to previous screen you can to use:

Get.back();

To go to the next screen and no option to go back to the previous screen (for use in SplashScreens, login screens and etc.)

Get.off(NextScreen());
//or 
Get.offNamed('/nextScreen');

To go to the next screen and cancel all previous routes (useful in shopping carts, polls, and exames)

Get.offAll(NextScreen(), (route) => false);
//or
Get.offAllNamed('/nextScreen', (route) => false);

To navigate to the next route, and receive or update data as soon as you return from it:

var data = await Get.to(Payment());

on other screen, send a data for previous route:

Get.back(result: 'sucess');

So, you can to use:

if(data == 'sucess') madeAnything();

SnackBars

To show a modern snackbar:

Get.snackbar('Hi', 'i am a modern snackbar');

To have a simple SnackBar with Flutter, you must get the context of Scaffold, or you must use a GlobalKey attached to your Scaffold, but with Get, all you have to do is call your Get.snackbar from anywhere in your code or customize it however you want!

  Get.snackbar(
               "Hey i'm a Get SnackBar!", // title
               "It's unbelievable! I'm using SnackBar without context, without boilerplate, without Scaffold, it is something truly amazing!", // message
              icon: Icon(Icons.alarm), 
              shouldIconPulse: true,
              onTap:(){},
              barBlur: 20,
              isDismissible: true,
              duration: Duration(seconds: 3),
            );

  ////////// ALL FEATURES //////////
  //     Color colorText,
  //     Duration duration,
  //     SnackPosition snackPosition,
  //     Widget titleText,
  //     Widget messageText,
  //     Widget icon,
  //     bool shouldIconPulse,
  //     double maxWidth,
  //     EdgeInsets margin,
  //     EdgeInsets padding,
  //     double borderRadius,
  //     Color borderColor,
  //     double borderWidth,
  //     Color backgroundColor,
  //     Color leftBarIndicatorColor,
  //     List<BoxShadow> boxShadows,
  //     Gradient backgroundGradient,
  //     FlatButton mainButton,
  //     OnTap onTap,
  //     bool isDismissible,
  //     bool showProgressIndicator,
  //     AnimationController progressIndicatorController,
  //     Color progressIndicatorBackgroundColor,
  //     Animation<Color> progressIndicatorValueColor,
  //     SnackStyle snackStyle,
  //     Curve forwardAnimationCurve,
  //     Curve reverseAnimationCurve,
  //     Duration animationDuration,
  //     double barBlur,
  //     double overlayBlur,
  //     Color overlayColor,
  //     Form userInputForm
  ///////////////////////////////////

Dialogs

To open dialog:

Get.dialog(YourDialogWidget());

To open default dialog:

 Get.defaultDialog(
                title: "My Title",
                content: Text("Hi, it's my dialog"),
                confirm: FlatButton(
                  child: Text("Ok"),
                  onPressed: () => print("OK pressed"),
                ),
                cancel: FlatButton(
                  child: Text("Cancel"),
                  onPressed: () => Get.back(),
                ));

BottomSheets

Get.bottomSheet is like showModalBottomSheet, but don't need of context.

Get.bottomSheet(
      builder: (_){
          return Container(
            child: Wrap(
            children: <Widget>[
            ListTile(
            leading: Icon(Icons.music_note),
            title: Text('Music'),
            onTap: () => {}          
          ),
            ListTile(
            leading: Icon(Icons.videocam),
            title: Text('Video'),
            onTap: () => {},          
          ),
            ],
          ),
       );
      }
    );

Dynamic Routes

You can use the dynamic route system to pass a value per parameter and get it in your view.


//use (: parameter_name) to use dynamic routes;
//use the args object that is a (ModularArguments) to get the value
 @override
  List<Router> get routers => [
      Router("/product/:id", child: (_, args) => Product(id: args.params['id'])),
  ];

A dynamic route is considered valid when the value corresponding to the parameter is filled. From this you can use:

 
Navigator.pushNamed(context, '/product/1'); //args.params['id']) gonna be 1
//or
Modular.to.pushNamed('/product/1'); //args.params['id']) gonna be 1

You can also pass an object using the "arguments" property in the navigation:

 
Navigator.pushNamed(context, '/product', arguments: ProductModel()); //args.data
//or
Modular.to.pushNamed('/product', arguments: ProductModel()); //args.data

getting on the route


 @override
  List<Router> get routers => [
      Router("/product", child: (_, args) => Product(model: args.data)),
  ];

Route Guard

We may protect our routes with middleware that will verify that the route is available within a given Route. First create a RouteGuard:

class MyGuard implements RouteGuard {
  @override
  bool canActivate(String url) {
    if(url != '/admin'){
      //code of authorization
      return true;
    } else {
      //access denied
      return false
    }
  }
}

Now put in the 'guards' property of your Router.

  @override
  List<Router> get routers => [
        Router("/", module: HomeModule()),
        Router("/admin", module: AdminModule(), guards: [MyGuard()]),
      ];

If placed on a module route, RouterGuard will be global to that route.

Route Transition Animation

You can choose which type of animation you want by setting the Router's ** transition ** parameter using the ** TransitionType ** enum.

Router("/product", 
        module: AdminModule(),
        transition: TransitionType.fadeIn), //use for change transition

If you use transition in a module, all routes in that module will inherit this transition animation.

Router generic types

You may need to navigate to a specific page and request a return value in the pop(), You can type the Router object with the value of that return;

 @override
  List<Router> get routers => [
    //type router with return type
    Router<String>('/event', child: (_, args) => EventPage()),
  ]

Flutter Web url Routes

The Routing System also recognizes what is typed in the website url (flutter web) so what you type in the browser url will open in the app. We hope this makes it easier for Flutter Web sites to make SEO more unique.

Dynamic routes apply here as well:

https://flutter-website.com/#/product/1

this will open the Product view and args.params 'id') will be equal to 1.

Dependency Injection

You can inject any class into your module using getter 'binds', for example classes BLoC, ChangeNotifier or Stores.

Bind is responsible for configuring object injection.

class AppModule extends MainModule {

 // here will be any class you want to inject into your project (eg bloc, dependency)
  @override
  List<Bind> get binds => [
    Bind((i) => AppBloc()), // using bloc
    Bind((i) => Counter()), // using ChangeNotifier
  ];

// here will be the routes of your module
  @override
  List<Router> get routers => [
      Router("/", child: (_, args) => HomePage()),
      Router("/login", child: (_, args) => LoginPage()),
  ];

// add your main widget here
  @override
  Widget get bootstrap => AppWidget();
}

Let's assume that for example we want to retrieve AppBloc inside HomePage.

//code in bloc
import 'package:get_modular/get_modular.dart' show Disposable;

// you can extend or implement from Disposable to define a discard for your class, if not.

class AppBloc extends Disposable {

  StreamController controller = StreamController();

  @override
  void dispose() {
    controller.close();
  }
}

Retrieving in view using injection.

You have some ways to retrieve your injected classes.

class HomePage extends StatelessWidget {

  @override
  Widget build(BuildContext context) {

    // You can use the object Inject to retrieve..
  
    final appBloc = Modular.get<AppBloc>();
    //...
  }
}

By default, objects in Bind are singletons and lazy. When Bind is lazy, the object will only be instantiated when it is called for the first time. You can use 'lazy:false' if you want your object to be instantiated immediately.

Bind((i) => OtherWidgetNotLazy(), lazy: false),

If you do not want the injected object to have a single instance, just use 'singleton: false', this will cause your object to be instantiated every time it is called

Bind((i) => OtherWidgetNotLazy(), singleton: false),

Using Modular widgets to retrieve your classes

ModularState

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends ModularState<MyWidget, HomeController> {

  //variable controller
  //automatic dispose off HomeController

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Modular"),
      ),
      body: Center(child: Text("${controller.counter}"),),
    );
  }
}

ModuleWidget

The same structure as ChildModule. Very useful for modular TabBar visualizations.

class TabModule extends ModuleWidget {

    @override
  List<Bind> get binds => [
    Bind((i) => TabBloc(repository: i.get<TabRepository>())),
    Bind((i) => TabRepository()),
  ];

  Widget get view => TabPage();

}

Consuming a ChangeNotifier Class

Example of a ChangeNotifier Class:

import 'package:flutter/material.dart';

class Counter extends ChangeNotifier {
  int counter = 0;

  increment() {
    counter++;
    notifyListeners();
  }
}

you can use the Consumer to manage the state of a widget block.

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {

    return Scaffold(
      appBar: AppBar(title: Text("Home"),
      ),
      body: Center(
     // recognize the ChangeNotifier class and rebuild when notifyListeners () is called
        child: Consumer<Counter>(
          builder: (context, value) {
            return Text('Counter ${value.counter}');
          }
        ),
      ),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: () {
          // retrieving the class directly and executing the increment method
          get<Counter>().increment();
        },
      ),
    );
  }
}

Creating Child Modules.

You can create other modules in your project, so instead of inheriting from MainModule, you should inherit from ChildModule.

class HomeModule extends ChildModule {
  @override
  List<Bind> get binds => [
    Bind((i) => HomeBloc()),
  ];

  @override
  List<Router> get routers => [
    Router("/", child: (_, args) => HomeWidget()),
    Router("/list", child: (_, args) => ListWidget()),
  ];

  static Inject get to => Inject<HomeModule>.of();

}

From this you can call your modules on the main module route.

class AppModule extends MainModule {

  @override
  List<Router> get routers => [
        Router("/home", module: HomeModule()),
        //...
      ];
}
//...

Consider splitting your code into modules such as LoginModule, and into it placing routes related to that module. Maintaining and sharing code in another project will be much easier.

Lazy Loading

Another benefit you get when working with modules is to load them "lazily". This means that your dependency injection will only be available when you navigate to a module, and as you exit that module, Modular will wipe memory by removing all injections and executing the dispose() methods (if available) on each module. injected class refers to that module.

Unit Test

You can use the dependency injection system to replace Links from mock links,as an example of a repository. You can also do it using "Inversion of Control"

@override
  List<Bind> get binds => [
        Bind<ILocalStorage>((i) => LocalStorageSharePreferences()),
      ];

We have to import the "get_modular_test" to use the methods that will assist with Injection in the test environment.

import 'package:get_modular/get_modular_test.dart';
import 'package:flutter_test/flutter_test.dart';
...

main() {
  test('change bind', () {
    initModule(AppModule(), changeBinds: [
      Bind<ILocalStorage>((i) => LocalMock()), 
    ]);
    expect(Modular.get<ILocalStorage>(), isA<LocalMock>());
  });
}

DebugMode

Remove prints debug:

Modular.debugMode = false;

Roadmap

This is currently our roadmap, please feel free to request additions/changes.

FeatureProgress
DI by Module
Routes by Module
Widget Consume for ChangeNotifier
Auto-dispose
Integration with flutter_bloc
Integration with mobx
Multiple routes
Pass arguments by route
Pass url parameters per route
Route Transition Animation

Features and bugs

Please send feature requests and bugs at the issue tracker.

Created from templates made available by Stagehand under a BSD-style license. license.

Libraries

get_modular
get_modular_test