iOS architecture patterns : MVC, MVP, MVVM, VIPER, and VIP in Swift

Develop well-structured applications using tested techniques and patterns. When you start to develop an application, you not only have to think about the idea of the finished application, but also about how it will evolve as it is built. This book shows you how to plan for changes, scope creep, and for the possibility of other developers joining in. Start by learning what architecture patterns for an application are. You’ll find out why it’s important for your applications to be based on these patterns and which ones are the most common. Then you’ll look at the MVC as one of the best known and used patterns. You’ll see how and when it can be implemented in your applications, as well as its advantages and disadvantages. From there, you’ll discover the first evolution of the MVC model: the MVP, which introduces a new layer (Presenter) to better manage views. The next evolution after that is the MVVM, which introduces the ViewModel layer and its connection with the views through Data Binding. With those prominent patterns covered, you’ll read about VIPER and VIP, Architecture Patterns that seeks to make applications easily maintainable, modularized, and highly scalable. All of which are hallmarks of Clean Architecture. Architecture patterns have developed and evolved to give your applications solid foundations. Understanding these patterns, you will reduce the problems that may arise when modifying existing functions, adding new ones, or correcting errors that may arise in the development process. What You'll Learn Code cleanly with solid foundations Start your project ready to adapt and evolve as features and other developers are added Find and apply the right patterns for the best results Who This Book Is For Developers with some programming knowledge who want to learn different architecture patterns, those who already have more experience and are looking for a starting point on complex patterns such as VIPER or VIP, and beginner programmers Table of Contents About the Author About the Technical Reviewer Acknowledgments Introduction Chapter 1: Introduction What Is Software Architecture? Architecture Patterns Why Do We Need an Architecture Pattern for Our Applications? Design from High Level to Low Level Design Patterns Creational Patterns Factory Method Abstract Factory Builder Singleton Prototype Structural Patterns Adapter Bridge Composite Decorator Façade Flyweight Proxy Behavioral Patterns Chain of Responsibility Command Interpreter Iterator Mediator Memento Observe State Strategy Template Method Visitor SOLID Principles Single-Responsibility Principle (SRP) Open–Closed Principle (OCP) Liskov Substitution Principle (LSP) Interface Segregation Principle (ISP) Dependency Inversion Principle (DIP) How to Choose the Right Architectural Pattern Most Used Architecture Patterns In Search of a “Clean Architecture” Clean Architecture Layers Domain Layer Presentation Layer Data Layer The Dependency Rule Advantages of Applying a Clean Architecture MyToDos: A Simple App to Test Architectures App Screens Launch Screen Home Screen Add List Screen Tasks List Screen Add Task Screen App Development Technologies Used How to Remove Storyboard Dependence Core Data Configuration How to Create Database and Entities Create CoreDataManager Summary Chapter 2: MVC: Model–View–Controller What Is MVC? A Little History Apple Model–View–Controller Components in MVC Model View Controller Advantages and Disadvantages of MVC Advantages of the MVC Pattern Disadvantages of the MVC Pattern MVC Application MVC Layers Model Core Data Models Services Extensions Constants View Controller MyToDos Application Screens Information Flow Delegate Pattern How to Implement Delegate Pattern AppDelegate and SceneDelegate Home Screen HomeViewController HomeView Add List Screen AddListViewController AddListView Tasks List Screen TaskListViewController TaskListView Add Task Screen AddTaskViewController AddTaskView Testing How Should the Tests Be? Let’s Create the First Test Helper Classes MVC-MyToDos Testing TasksListServiceTest Mocking Services Controllers Testing Views Testing Summary Chapter 3: MVP: Model–View–Presenter What Is MVP? A Little History How It Works Components in MVP Model View Presenter Advantages and Disadvantages of the MVP Advantages Disadvantages MVP Application MVP Layers Model Core Data Models Services Extensions Constants View Presenter MyToDos Application Screens AppDelegate and SceneDelegate Home Screen HomeController HomeView HomePresenter Add List Screen AddListViewController AddListView AddListPresenter Tasks List Screen TaskListViewController TaskListView TaskListPresenter Add Task Screen AddTaskViewController AddTaskView AddTaskPresenter MVP-MyToDos Testing AddListViewController AddListView AddListViewPresenter Summary Chapter 4: MVVM: Model–View–ViewModel What Is MVVM? A Little History How It Works Components in MVVM Model View ViewModel Data Binding Advantages and Disadvantages of MVVM Advantages Disadvantages MVVM Application MVVM Layers Model Core Data Models Services Extensions Constants View ViewModel MyToDos Data Binding What Is RxSwift? Observables and Observers Installing RxSwift Input/Output Approach MyToDos Application Screens AppDelegate and SceneDelegate Home Screen HomeViewController HomeView HomeViewModel Add List Screen AddListViewController AddListView AddListViewModel Tasks List Screen TaskListViewController TaskListView TasksListViewModel Add Task Screen AddTaskViewController AddTaskView AddTaskViewModel MVVM-MyToDos Testing RxTest Introduction HomeViewModel Tests EmptyState Test Testing the Deletion of Lists List Selection Testing MVVM-C: Model–View–ViewModel–Coordinator What Is a Coordinator? Using MVVM-C in MyToDos SceneDelegate Home Screen Add List Screen Tasks List Screen Add Task Screen Summary Chapter 5: VIPER: View–Interactor–Presenter–Entity–Router What Is VIPER? A Little History How It Works Components in VIPER View Interactor Presenter Entity Router Advantages and Disadvantages of VIPER Advantages Disadvantages VIPER Application Communication Between Components Communication Between Presenter and View Communication Between Presenter and Interactor Communication Between Presenter and Router VIPER Layers Modules Services Common Core Data Components Models Extensions Helpers MyToDos Application Screens AppDelegate and SceneDelegate Home Module Home Protocols HomeRouter HomeViewController HomePresenter HomeInteractor Add List Module AddListProtocols AddListRouter AddListViewController AddListPresenter AddListInteractor Task List Module TaskListProtocols TaskListRouter TaskListViewController TaskListPresenter TaskListInteractor Add Task Module AddTaskProtocols AddTaskRouter AddTaskViewController AddTaskPresenter AddTaskInteractor VIPER-MyToDos Testing HomePresenter HomeInteractor Summary Chapter 6: VIP: View–Interactor–Presenter What Is VIP? A Little History How It Works Components in VIP View (UIViewController) Interactor Presenter Router Worker/Service Model Configurator Advantages and Disadvantages of VIP Advantages Disadvantages VIP Layers Scenes Services/Workers Common Core Data Components Models Extensions Helpers MyToDos Application Screens AppDelegate and SceneDelegate Home Scene HomeConfigurator HomeView HomeViewController HomeInteractor HomePresenter HomeModel HomeRouter AddList Scene AddListConfigurator AddListView AddListViewController AddListInteractor AddListPresenter AddListModel AddListRouter TaskList Scene TaskListConfigurator TaskListView TaskListViewController TaskListInteractor TaskListPresenter TaskListModel TaskListRouter AddTask Scene AddTaskConfigurator AddTaskView AddTaskViewController AddTaskInteractor AddTaskPresenter AddTaskModel AddTaskRouter VIP-MyToDos Testing HomeViewControllerTest HomeInteractorTest HomePresenterTest Summary Chapter 7: Other Architecture Patterns Introduction RIBs: Router, Interactor, and Builder A Little History How It Works Components Router Interactor Builder Component Presenter View Advantages and Disadvantages Advantages Disadvantages The Elm Architecture A Little History How It Works Components Model View Update Runtime Advantages and Disadvantages Advantages Disadvantages Redux A Little History How It Works Components State Store Reducer Action View Middleware Advantages and Disadvantages Advantages Disadvantages TCA: The Composable Architecture A Little History How It Works Components State View Action Reducer Environment (Effect) Store Advantages and Disadvantages Advantages Disadvantages Summary Chapter 8: Conclusion The Importance of Clean Architecture Moving Forward Index