llinardos

func onMainDo<T>(_ firstMainBlock: @escaping () -> Void, onBackgroundDo backgroundBlock: @escaping () -> T, thenOnMainDo mainBlock: @escaping (T) -> Void) {
    DispatchQueue.main.async {
        firstMainBlock()
        DispatchQueue.global(qos: .background).async {
            let result = backgroundBlock()
            DispatchQueue.main.async {
                mainBlock(result)
            }
        }
    }

llinardos

let service = SyncronousThingsService()
onMainDo({
    self.activityIndicator.startAnimating()
}, onBackgroundDo: {
    return service.getThings()
}, thenOnMainDo: {
    self.activityIndicator.stopAnimating()
    self.updateUI(with: $0)
})

llinardos

let syncService = SyncronicThingsService()
activityIndicator.startAnimating()
DispatchQueue.global(qos: .background).async {
    let getThingsResult = syncService.getThings()
    DispatchQueue.main.async {
        activityIndicator.stopAnimating()
        updateUI(with: getThingsResult)
    }
}

llinardos

let service = ThingsService()
activityIndicator.startAnimating()
service.getThings { getThingsResult in
    activityIndicator.stopAnimating()
    updateUI(with: getThingsResult)
}

llinardos

class ThingsService {
    func getThings() -> Result<[Thing]> {
        do {
            let response = try sendHttpRequestSynchronously(url)
            let data = try getData(from: response)
            let things = try doParsing(data)
            return .success(things)
        } catch error {
            return .failure(error)
        }

llinardos

class ThingsService {
    func getThings(onCompletion callback: @escaping (Result<[Thing]>) -> Void) {
        sendHttpRequestAsynchronously(url) { response in
            DispatchQueue.main.async {
                do {
                    let data = try getData(from: response)
                    let things = try doParsing(data)
                    callback(.success(things)))
                } catch error {
                    callback(.failure(error))

llinardos

class Tap {
  private static var instances: [Tap] = []
  
  // ...  

  static func on(view: UIView, fires action: @escaping () -> Void) {
    let tap = Tap(view: view, action: action)
    Tap.instances.append(tap)
  }
  

llinardos

class Tap {
  private var view: UIView
  private var action: () -> Void

  init(view: UIView, action: @escaping () -> Void) {
    self.view = view
    self.action = action
        
    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(onTap(_:)))
    view.addGestureRecognizer(tapGesture)

llinardos

func aMethod() {
  aView.onTap { /* action */ }
  // or
  Tap.on(aView) { /* action */ }
}

llinardos

func aMethod() {
  let tapGesture = UITapGestureRecognizer(target: self, action: #selector(onTap(_:)))
  aView.addGestureRecognizer(tapGesture)
}

@objc func onTap(_ gesture: UIGestureRecognizer) {
  if (gesture.state == .ended) {
    /* action */
  }
}