Presentation

An architecture for Android as a replacement of MVC.

Why should I use Presentation?

Because you want to have more readable, testable code.

Avoid "God Objects", mainly your Activities or Fragments.

How does it work?

Separation of responsibilities by module:

• Presenter: Get a Business Object from the DataProvider and give instructions to the ViewProxy
• DataProvider: Communicate with the "outside" to set and get the data, following the instructions of the Presenter
• ViewProxy: Convert Presenter instructions and set values to Android Views.

Architecture

Leak safe. Don't hold a strong reference to the DataProvider, Presenter, or ViewProxy.

Sample

The goal is to make this application:

Each public method of the modules are defined into an interface:

public interface FormDef {

interface IPresenter extends Base.IPresenter {

 void onClickSaveButton(String value);

  
}

interface IDataProvider extends Base.IDataProvider {

 String getValueSaved();

 void saveValue(String value);

  
}

interface IView extends Base.IView {

 void setValueSaved(String text);

  
}
  
}
 

Then you have your:

• FormPresenter that extends BasePresenter and implements FormDef.IPresenter
• FormDataProvider that extends BaseDataProvider and implements FormDef.IDataProvider
• FormViewProxy that extends BaseViewProxy and implements FormDef.IView

Go further

Presenter into an Adapter

This library has a dependency on Efficient Adapter to use the same view cache mechanism.

This allows to apply the Presentation pattern to object in an Adapter as well. Your ViewHolder should extend PresenterViewHolder and your Presenter should extend BaseItemPresenter.

Let your Presenter by Lifecycle aware

Thanks to the Android Architecture Components, your Presenter can be aware of the lifecycle of the linked Activity or Fragment.

It will be automatically registered/unregistered if your Presenter implements LifecycleObserver, if it extends BasePresenter.

Then you can add the annotation @OnLifecycleEvent for the state you want to listen.

Example:

public class MyPresenter extends BasePresenter<MyDef.IDataProvider, MyDef.IView>

implements MyDef.IPresenter, LifecycleObserver {

...

@OnLifecycleEvent(Lifecycle.Event.ON_START)
  void onStart() {

// do whatever when the
  
}
  
}
 

Proguard

Nothing special needed.

Gradle

dependencies {

  compile 'com.skocken:presentation:2.0.0' 
}
 

License

• Apache 2.0

Contributing

Please fork this repository and contribute back using pull requests.

Any contributions, large or small, major features, bug fixes, unit/integration tests are welcomed and appreciated but will be thoroughly reviewed and discussed.