mvcprovider

If you come from version 1, please look at the changelog to handle the V2 breaking changes.

Create a simple MVC architecture based on the Provider package. The most recommended state management package by Flutter founders.

  • Start creating value fast with a clear and well structured code.

    • Module
      • Model
      • View
      • Controller

  • Simplest lifecycle management from the controller AND/OR the model.

    • create() // Called once before first view rendering
    • update() // Called every view rendering

  • The easiest way to inject dependencies, services or providers. You just have to create a class which extend MVC_Notifier or MVC_Provider

   // In the module
   // You can inject all providers that you will use in children:
   final List<SingleChildWidget> providers = [
     MyThemeService().create,
     MyUserStateService().create,
   ];
  • Access to your previously declared dependencies just by calling MyThemeService(context).listen or MyThemeService(context).get anywhere in your code

Getting Started with the official Flutter example

Everybody need to create a counter module, and of course you need it too.

STEP 1

First, define your very complex model (my.counter.model.dart) :

    class MyCounterModel extends MVC_Model<MyCounterCtrl> {
    
       int _count = 0;
       set count(int value) {
         _count = value;
         notifyListeners();
       }
       int get count => _count;
    }

STEP 2

Then define a controller that will increment the count property with a lot of mathematics operations (my.counter.ctrl.dart) :

    class MyCounterCtrl extends MVC_Controller<MyCounterModel> {
    
       void increment() {
         model.count++;
       }
    }

For now, you have an amazing method increment that will increment (no ?! really ??) you're model's property count which will call refresh (a method alias for the method notifyListeners inherited from her mother class ChangeNotifier) in order to refresh the view.

STEP 3

But to refresh the view. You need a view. Here it is (my.counter.view.dart) :

    class MyCounterView extends StatelessWidget with MVC_View<MyCounterModel, MyCounterCtrl> {
          @override
          Widget build(BuildContext context, [Widget? child]) {
            listen(context);
        
            return Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text("Counter : ${model.count}"),
                  RaisedButton(child: Text("Increment"), onPressed: ctrl.increment)
                ]
            );
          }
        }

It's a bit complicated view. I'll explain : it's a text on top of a button.

Like you can see the text display our model's property count and the button execute our controller's method increment when pressed.

STEP 4

In order to make the magic happen you'll need to link these three entities together, I decided that this fusion will be called a Module but you can call this Roberto or anything else if you prefer.

Here is our module (my.counter.dart) :

    class MyCounterModule extends MVC_Module<MyCounterModel, MyCounterView, MyCounterCtrl> {
    
       final MyCounterModel model = MyCounterModel();
       final MyCounterView view = MyCounterView();
       final MyCounterCtrl ctrl = MyCounterCtrl();
       final List<SingleChildWidget> providers = [];
    }

STEP 5

To test you newly counter feature in your app just call your widget MyCounterModule() Example in your main.dart file :

    void main() => runApp(AmazingSample());
    
    class AmazingSample extends StatelessWidget {
      // This widget is the root of this amazing package sample.
      @override
      Widget build(BuildContext context) {
        return MaterialApp(
          title: 'MVC Provider counter demo',
          home: MyCounterModule(),
        );
      }
    }

At this point you should have a main.dart file and a mycounter folder with 4 files inside :

  • The module my.counter.dart

  • The model my.counter.model.dart

  • The view my.counter.view.dart

  • The controller my.counter.ctrl.dart

Libraries

mvcprovider