A Deep Dive into iOS ReactorKit

The OLIVE YOUNG mobile app development team adopted ReactorKit, an architecture with strengths in maintainability and testing, for refactoring the native area. ReactorKit is used together with RxSwift, and is effective at separating UI logic from business logic to increase code reusability.

The core of ReactorKit is the Reactor, which plays a role similar to the ViewModel in MVVM. The data flow follows a Unidirectional structure in which the View emits an Action, the Reactor receives it and generates a new State through a Mutation, which is then passed back to the View.

The main components are as follows:

• View: Updates the UI through State, and passes user interactions as Actions.
• Reactor: Converts Actions into Mutations (mutate), and combines the previous State with the Mutation to return a new State (reduce).
• Action: Represents a user's interaction.
• Mutation: Acts as an intermediary between Action and State.
• State: Defines the state that the View will display.