iOS Best Practices. Part 3: Architecture

• View – This is a UIViewController, which has outlets to views and handles user interaction. View has 2 protocols.
  View Input – implemented in View Layer and called from Presenter Layer.
  *Display info on View, g. showProgress()
  View Output – implemented in Presenter Layer and called from View Layer.
  *Notify presenter about User actions,e.g. addNewItem()
  
• Presenter – This is a class that communicates with View, Router and Interactor using next protocols.
  View Output – look at View section.
  Interactor Output – implemented in Presenter Layer and called from Interactor Layer.
  *Notify presenter about updates,g. dataDidLoad()
  View Input – look at View section.
  Interactor Input – implemented in Interactor Layer and called from Presenter Layer.
  *Asks for updates, e.g. loadItems()
  Router Input – implemented in Router Layer and call from Presenter Layer.
  *Navigate between modules, e.g. showDetailsModule()
  
• Interactor – This is a class that communicates with Presenter and Entities. Interactor has 2 protocols.
  Interactor Input – look at Presenter section.
  Interactor Output – look at Presenter section.
  
• Entity – These include any data representation such as CoreData Entity, Realm Object, etc.
  
• Configurator – One more thing.
  VIPER has lots of components that we need to inject between.
  Configurator injects layers between them.

This was a brief guide to the clean architecture VIPER.

Continue reading: iOS Best Practices. Part 4: S.O.L.I.D. >>>

Maxim Vialykh is CactusSoft iOS Tech Lead.

Technical Background
Programming languages: Swift, Objective-C, Java
Technologies and Platforms: iOS, Android, Windows Phone, Amazon S3, Google Cloud, Google APIs, Facebook APIs
Frameworks: PhoneGap, Xamarin
Tools: Invision, SVN, Git, PhoneGap, Titanium, Xamarin, Sketch, xCode, IntelliJ IDEA