AlertReactor

AlertReactor is a ReactorKit extension for UIAlertController. It provides an elegant way to deal with an UIAlertController. Best fits if you have lazy-loaded alert actions.

Features

• ✏️ Statically typed alert actions
• 🕹 Reactive and dynamic action bindings

At a Glance

This is an example implementation of an AlertReactor:

final class UserAlertReactor: AlertReactor<UserAlertAction> {
  override func mutate(action: Action) -> Observable<Mutation> {
    switch action {
    case .prepare:
      return .just(.setActions([.copy, .follow, .block, .cancel]))

    case let .selectAction(alertAction):
      switch alertAction {
      case .copy: return foo()
      case .follow: return foo()
      case .unfollow: return foo()
      case .block: return foo()
      case .cancel: return foo()
      }
    }
  }
}

Getting Started

1. Defining an Alert Action

First you should define a new type which conforms to a protocol AlertActionType. This is an abstraction model of UIAlertAction. This protocol requires a title(required), style(optional) and isEnabled(optional) property.

enum UserAlertAction: AlertActionType {
  case loading
  case follow
  case block
  case cancel

  // required
  var title: String {
    switch self {
    case .loading: return "Loading"
    case .follow: return "Follow"
    case .block: return "Block"
    case .cancel: return "Cancel"
    }
  }

  // optional
  var style: UIAlertActionStyle {
    switch self {
    case .loading: return .default
    case .follow: return .default
    case .block: return .destructive
    case .cancel: return .cancel
    }
  }

  // optional
  var isEnabled: Bool {
    switch self {
    case .loading: return false
    default: return true
    }
  }
}

2. Creating an Alert Reactor

AlertReactor is a generic reactor class. It takes a single generic type which conforms to a protocol AlertActionType. This reactor provides a default action, mutation and a state. Here is a simplified definition of AlertReactor. You may subclass this class and override mutate(action:) method to implement specific business logic.

class AlertReactor<AlertAction: AlertActionType>: Reactor {
  enum Action {
    case prepare // on viewDidLoad()
    case selectAction(AlertAction) // on select action
  }

  enum Mutation {
    case setTitle(String?)
    case setMessage(String?)
    case setActions([AlertAction])
  }

  struct State {
    public var title: String?
    public var message: String?
    public var actions: [AlertAction]
  }
}

We're gonna use the UserAlertAction as a generic parameter to create a new subclass of AlertReactor.

final class UserAlertReactor: AlertReactor<UserAlertAction> {
  override func mutate(action: Action) -> Observable<Mutation> {
    switch action {
    case .prepare:
      return .just(Mutation.setActions([.copy, .follow, .block, .cancel]))

    case let .selectAction(alertAction):
      switch alertAction {
      case .loading: return .empty()
      case .follow: return UserAPI.follow()
      case .block: return UserAPI.block()
      case .cancel: return .empty()
      }
    }
  }
}

3. Presenting an Alert Controller

AlertController is a subclass of UIAlertController which conforms to a protocol View from ReactorKit. This class also takes a single generic type of AlertActionType. You can initialize this class with some optional parameters: reactor and preferredStyle. Just present it then the reactor will handle the business logic for you.

let reactor = UserAlertReactor()
let controller = AlertController<UserAlertAction>(reactor: reactor, preferredStyle: .actionSheet)
self.present(controller, animated: true, completion: nil)

Installation

pod 'AlertReactor'

License

AlertReactor is under MIT license. See the LICENSE for more info.