نمط Coordinator لتواصل المفوَّض

لماذا نستخدم المنسّقات؟

struct ImagePicker: UIViewControllerRepresentable {
  @Binding var image: UIImage?
  // Coordinator will be the UIImagePickerControllerDelegate
}

makeCoordinator()

func makeCoordinator() -> Coordinator {
  Coordinator(self)
}

فئة Coordinator

class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
  var parent: ImagePicker
  init(_ parent: ImagePicker) { self.parent = parent }
}

تعيين المفوّض

func makeUIViewController(context: Context) -> UIImagePickerController {
  let picker = UIImagePickerController()
  picker.delegate = context.coordinator
  return picker
}

تطبيق أساليب المفوّض

func imagePickerController(
  _ picker: UIImagePickerController,
  didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey: Any]
) {
  parent.image = info[.originalImage] as? UIImage
  picker.dismiss(animated: true)
}

استدعاء الإلغاء

func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
  picker.dismiss(animated: true)
}

مصدر البيانات عبر Coordinator

class Coordinator: NSObject, UITableViewDataSource {
  var parent: MyTableView
  init(_ p: MyTableView) { parent = p }
  func tableView(_ tv: UITableView, numberOfRowsInSection s: Int) -> Int { parent.items.count }
  func tableView(_ tv: UITableView, cellForRowAt ip: IndexPath) -> UITableViewCell {
    let cell = tv.dequeueReusableCell(withIdentifier: "cell", for: ip)
    cell.textLabel?.text = parent.items[ip.row]
    return cell
  }
}

إبقاء Coordinator محدّثًا

func updateUIViewController(_ vc: UIImagePickerController, context: Context) {
  context.coordinator.parent = self
}

مفوّضون متعددون

class Coordinator: NSObject,
  UIScrollViewDelegate,
  UITextViewDelegate,
  UISearchBarDelegate { ... }

Coordinator مقابل @Binding

// Simple: @Binding var text: String -> updateUIView writes uiView.text = text
// Complex: coordinator mediates UITextViewDelegate -> parent.text = textView.text

دورة حياة Coordinator

// makeCoordinator called once → stable delegate reference
// updateUIView called many times → push state changes

فحص سريع

مراجعة الدرس