bill350

class ErrorView: UIView, NibLoadable {

  // MARK: Properties
  weak var delegate: ErrorViewDelegate?
  var animationDuration = 0.3
  fileprivate(set) var isAnimating = false

  // MARK: - Overrides
  override func awakeFromNib() {
    super.awakeFromNib()

bill350

// MARK: - ErrorDisplayable
extension ErrorView: ErrorDisplayable {

  static func show<T: ErrorView>(
    fromViewController viewController: UIViewController,
    animated: Bool = true,
    completion: ((Bool) -> Swift.Void)? = nil) -> T {

    guard let subview = loadFromNib() as? T else {
      fatalError("The subview is expected to be of type \(T.self)")

bill350

// MARK: - ErrorAnimatable
extension ErrorView: ErrorAnimatable {

  func playAnimation() {
    self.isAnimating = true
  }

  func stopAnimation() {
    self.isAnimating = false
  }

bill350

class ProgressView: UIView, NibLoadable {

  // MARK: Properties
  var animationDuration = 0.3
  fileprivate(set) var isAnimating = false

  // MARK: - Overrides
  override func awakeFromNib() {
    super.awakeFromNib()

bill350

protocol Localizable {
  var localizedMessage: String { get }
}

protocol Underlying {
  var underlying: Swift.Error? { get }
}

bill350

extension Error {

  var localizedMessage: String {
    if let error = self as? SignIn.Error { return error.underlying?.localizedMessage ?? error.localizedMessage }
    if let error = self as? Network.Error { return error.localizedMessage }
    if let error = self as? Store.Error { return error.localizedMessage }
    return L10n.commonErrorMessage // Fallback error message
  }

  var underlying: Swift.Error? {

bill350

struct SignIn {

  enum Error: Swift.Error, Localizable, Underlying {

    case unknown(underlying: Swift.Error?)
    case invalidCredentials(underlying: Swift.Error?)
    case mailEmpty
    case mailIncorrect
    case passwordIncorrect
    case serviceInconsistency

bill350

// MARK: - UIViewController Default implementation
extension FailableCore where Self: UIViewController {

  func showError(_ error: Swift.Error?) {

    let errorMessage = error?.localizedMessage ?? L10n.commonErrorMessage

    SwiftMessages.showAlert(title: errorMessage)

  }

bill350

// MARK: - ViewController Default implementation
extension Failable where Self: ViewController {

  func showError<T: ErrorDisplayable>(_ error: Swift.Error?, errorView: T.Type, _ reloadable: Reloadable) {
    self.errorView = errorView.show(fromView: self.view, insets: .zero, animated: true, completion: nil)

    if var errorViewRetryable = self.errorView as? ErrorRetryable {
      errorViewRetryable.retry = { reloadable.reloadData() }
      errorViewRetryable.message = error?.localizedMessage
    }

bill350

class ViewController: UIViewController {

  var errorView: ErrorView?
  var progressView: ProgressView?
}