/SWVLMovies

Primary LanguageSwift

SWVLMovies

SWVLMovies is an iOS application built as interview task at Swvl. Built Using MVP (Model-View-Presenter) and Clean Architecture concepts

Run Requirements

  • Xcode 10.2
  • Swift 5

Installation

  1. Clone the porject.
  2. Navigate to project folder in terminal.
  3. Run make bootstrap
  4. Provide your flicker API key when asked (while install cocoapods)

High Level Layers

MVP Concepts (Presentation Logic or Scenes)

  • View - delegates user interaction events to the Presenter and displays data passed by the Presenter
  • All UIViewController, UIView, UITableViewCell subclasses belong to the View layer
  • Usually the view is passive / dumb - it shouldn't contain any complex logic and that's why most of the times I don't need write Unit Tests for it
  • Presenter - contains the presentation logic and tells the View what to present
  • Usually I have one Presenter per scene (view controller)
  • It doesn't reference the concrete type of the View, but rather it references the View protocol that is implemented usually by a UIViewController subclass
  • It should be a plain Swift class and not reference any iOS framework classes - this makes it easier to reuse it maybe in a macOS application
  • It should be covered by Unit Tests
  • Configurator - injects the dependency object graph into the scene (view controller)
  • Unfortunately DI libraries are not quite mature yet on iOS / Swift
  • Usually it contains very simple logic and I don't need to write Unit Tests for it
  • Router - contains navigation / flow logic from one scene (view controller) to another
  • In some communities / blog posts it might be referred to as a FlowController
  • Writing tests for it is quite difficult because it contains many references to iOS framework classes so usually I try to keep it really simple and I don't write Unit Tests for it
  • It is usually referenced only by the Presenter but due to the func prepare(for segue: UIStoryboardSegue, sender: Any?) method I some times need to reference it in the view controller as well

Clean Architecture Concepts

Application Logic (Core)
  • UseCase / Interactor - contains the application / business logic for a specific use case in your application
  • It is referenced by the Presenter. The Presenter can reference multiple UseCases since it's common to have multiple use cases on the same screen
  • It manipulates Entities and communicates with Gateways to retrieve or persist the entities
  • Gateway is defiend as a protocols and should be defined in the Application Logic layers and implemented by the Gateways & Framework Logic
  • The separation described above ensures that the Application Logic depends on abstractions and not on actual frameworks or implementations
  • It should be covered by Unit Tests
  • Entity - plain Swift classes or structs
  • Models objects used by your application such as Movie or what ever needed
Gateways & Framework Logic (EntityGateway)
  • Gateway - contains actual implementation of the protocols defined in the Application Logic layer
  • We can implement for instance a LocalPersistenceGateway protocol using CoreData or Realm
  • We can implement for instance an ApiGateway protocol using URLSession or Alamofire, and that I going to use in the scope of task
  • It should be covered by Unit Tests
  • Persistence / API Entities - contains framework specific representations
  • For instance we could have a APIMovie that is conform Codable or Mappaple
  • The APIMovie would not be passed to the Application Logic layer but rather the Gateways & Framework Logic layer would have to "transform" it to an Movie entity defined in the Application Logic layer