Code snippets for the blog post on MVC-RS

mvvm-rrosrws.md

Code snippets for the blog post "Let me tell you a storey" at http://www.apokrupto.com/blog-1/2016/10/22/mvc-rrosrws

new-store-model.swift

protocol HeartRateStoring {
  var source: HeartRateDataSource? { get }
  var sink: HeartRateDataSink? { get }
}

struct HeartRateStore: HeartRateStoring {
  let source: HeartRateDataSource?
  let sink: HeartRateDataSink?
}

rw-backend.swift

let backend = HeartRateBackend()
let rwStore = HeartRateStore(source: backend, sink: backend)

sensor-and-backend-model.swift

struct HeartRateSensor: HeartRateDataSource {
  func read(at: Int) -> HeartRate {
    // ...
  }
}

struct HeartRateBackend: HeartRateDataSource, HeartRateDataSink {
  func read(at: Int) -> HeartRate {
    // ...
  }

  func write(heartRate: HeartRate) {
  }
}

sensor-and-backend-vars.swift

let sensor  = HeartRateSensor()
let backend = HeartRateBackend()

let liveDataViewModel = ViewModel(store: HeartRateStore(source: sensor, sink: backend))
let historyViewModel  = ViewModel(store: HeartRateStore(source: backend, sink: nil))

source-sink.swift

protocol HeartRateDataSource {
  func read(at: Int) -> HeartRate
}

protocol HeartRateDataSink {
  func write(heartRate: HeartRate)
}

store-model.swift

struct HeartRate {
    var value: Int
}

protocol HeartRateStoring {
  func read(at: Int) -> HeartRate
  func write(heartRate: HeartRate)
}

struct HeartRateStore: HeartRateStoring {
  func read(at: Int) -> HeartRate {
    // returns a HeartRate
  }

  func write(heartRate: HeartRate) {
    //...
  }
}

view-controller-router.swift

class ViewController: UIViewController {
  private let viewModel: HeartRateViewModelling

  init(viewModel: HeartRateViewModelling) {
    self.viewModel = viewModel
  }
}

// Somewhere else i.e. in the Router/Coordinator
let vc = ViewController(viewModel: ViewModel(store: HeartRateStore()))

view-controller-storyboard.swift

class ViewController: UIViewController {
  var viewModel: HeartRateViewModelling!

  override func viewDidLoad() {
    super.viewDidLoad()
    viewMode = ViewModel(store: HeartRateStore())
  }
}

view-model.swift

protocol HeartRateViewModelling {
  var store: HeartRateStoring { get }
}

struct ViewModel: HeartRateViewModelling {
  let store: HeartRateStoring
}