Clean Swift

Coined by Raymond Law in 2015

• Wanted to improve testability in his projects.

• "Clean Swift is not a framework. It is simply a set of Xcode templates to generate the Clean Architecture components for you."

• https://clean-swift.com

Scene

In Clean Swift the project structure is built around scenes (or screens)

• Model

• View Controller

• Router

• Interactor

• Presenter

• Worker

• Configurator

Use Xcode templates for creating scenes

Configurator

Initializes and connects all the previously mentioned components

Model

Use case structures defining data passed between components

• Request (View Controller)

• Input data coming from the view controller to invoke some business logic in the interactor.

• Response (Interactor)

• The result of some work passed from the interactor to the presenter.

• View Model (Presenter)

• The prepared data from the presenter for the view controller to update the views.

View Controller (Clean Swift)

The role of a View Controller is practically demoted to that of a view

• Still receives calls to lifecycle methods

• viewDidLoad, viewWillAppear, viewWillDisappear...

• Still serves as the delegate

• UITableViewDataSource, UITableViewDelegate...

• Still handles user interaction

• @IBAction...

• No longer contains any business logic

• This role is assumed by the Interactor

• No longer transforms/prepares data for displaying

• This role is assumed by the Presenter

• No longer serves data and prepares the next
  view controller

• This role is assumed by the Router

Interactor

The interactor handles all business logic and serves as a data store

• This includes

• Input data validation

• Choosing which Worker is suitable for the task

• Invoking the Workers to perform the actual processing

• Storing the required data

• Creating a response data and passing

it to the Presenter

Worker

Handles all the API request/response calls for the Interactor

Presenter

The presenter transforms and prepares response data for displaying

• The response from the Interactor usually contains data in some non-formatted way

• Date, NSNumber, CustomObject, ...

• The ViewController in most cases needs simple values as Strings for displaying

• Presenter formats the Date using a DateFormatter

• String result is sent to the ViewController

Router

The router handles the navigation and passes the data between scenes

• Navigation

• Automatic segue

• Manual segue

• Programmatic

• Data passing

• Using the Interactor's Data Store capability