VIPERBuilder

Scaffolding for building apps in a clean way with VIPER architecture.

• What is VIPER?.
• How does Etsy use VIPER?
• Check out VIPERBuilder on FLOSSWeekly

VIPER inherently has a few problems:

• Boilerplate
• Potential retain cycles due to management of many classes
• Cognitive overhead of setup

This framework aims to address those problems by providing a set of base classes to divide your app's functionality and builder object to manage the connections.

Installation

Cocoapod

Add pod VIPERBuilder to your Podfile

Run pod install

Usage

1. Create subclasses of VIPERInteractor, VIPERPresenter and VIPERRouter as needed

2. Create a strong reference to an instance of VIPERBuilder with the new subclasses specified. Lazy loading in Swift will ensure that the builder object is available as soon as it is called

   lazy var viperBuilder: VIPERBuilder<NewInteractor, NewPresenter, NewRouter> = { return VIPERBuilder(controller: self) }()

Note: If not all classes are needed for the implementation passing the superclass to the Builder object is supported

For a more detailed implementation, please check out the demo project included in this repo

Code Separation

This framework provides three base classes for the three main parts of VIPER: Interactor, Presenter, Router. Each class should contain certain pieces of code and has references to other classes for specific reasons, however these can be extended through subclassing.

Interactor

Purpose

• User interaction (directly and through delegation from other classes)
• Data fetching/mutation

Reference usages

• Presenter: should be used to update view after fetching or mutating data
• Router: Used for navigation based on actions taken

Presenter

Purpose

• Configuring view/view model (entity objects)
• Presenting modals/loading screens

Reference usages

• Controller: Presenting modals/error messages
• Interactor: Can be used as a delegate for any actions from views

Router

Purpose

• Navigation (pushing views onto UINavigationController's stack)

Reference usages

• Navigation controller: Used for pushing screens