mvp_core 0.0.3

A generic Flutter implementation of the MVP (model/view/presenter) pattern which allows for more testable code.

mvp_core

An MVP (model/view/presenter) framework for applications written in dart. This package gives specific support to the flutter framework.

Getting Started

The following code is a stubbed out tutorial of how to use this package. See the example directory in the repository of this package for a more complete example. You can find the repository here.

Create the presenter (and the interfaces it expects). I recommend placing these 3 classes in the same file because they are all closely related to eachother.

/// The interface the presenter will use to communicate with the view.
abstract class IMyView extends IView { ... }

/// The interface the view will use to communicate with the presenter.
abstract class IMyPresenter extends IPresenter { ... }

/// The concrete presenter which updates the view and the model.
class MyPresenter extends Presenter<IMyView> implements IMyPresenter { ... }

Create the view (using the interfaces the presenter expects). I again recommend placing these classes in the same file because they are closesly related to each other.

/// Since the presenter updates the view's state,
/// the view should be a [StatefulWidget].
class MyPage extends StatefulWidget {
    @override
    _MyPageState createState() => _MyPageState();
}

/// The concrete view which the presenter updates. The view depends 
/// on the presenter and implements the interfaces it expects
class _MyPageState extends StateView<MyPage, IMyPresenter> implements IMyView {

    /// Builds the UI for the view just like any
    /// other flutter stateful widget.
    @override
    Widget build(BuildContext context) { ... }

    /// Create the presenter which will update this view.
    ///
    /// This is the only place where the concrete presenter
    /// should be referenced in the view.
    @override
    IMyPresenter createPresenter() => MyPresenter();
}

Purpose

Weak coupling

This package attempts to create a weak coupling between views and presenters in flutter applications. This means that views only know about the interfaces of their associated presenters and presenters only know about the interfaces of their associated views.

Automated testing

Because of weak coupling, automatically testing an application becomes trivial. See Testing.

No assumptions about the model

This package makes no assumptions about the model of your application. This means that any model (or data) you choose (as well as whatever model pattern) will work with this framework.

Testing

"The MVP pattern is a variation of the MVC pattern that results in more testable code."

Since the coupling between the views and the presenters is strictly through interfaces, it's easy to create a MockView to test the presenter. See the example directory of this package's repository for and example of how to do this.

To test the widgets, you can simply perform the same widget-tests that you would perform in any other application.