(UIKit >> SwiftUI) Inline bridge view using some @dynamicMemberLookup magic.

BridgeView.swift

import Foundation
import UIKit
import SwiftUI

// MARK: - UIViewBridge

/// Usage:
///
/// var body: some View {
///   ...
///   UIViewBridge<UILabel> { view, context in
///     view.backgroundColor = UIColor.red
///     view.text = "Hello"
///   }
///   ...
public struct UIViewBridge<T: UIView>: UIViewRepresentable {
  public typealias Coordinator = UIViewBridgeCoordinator<T>
  public typealias Context = UIViewRepresentableContext<UIViewBridge<T>>

  /// Reference to the concrete `UIView` instance.
  public let view: T

  /// The `UIViewRepresentable` coordinator object.
  /// - note: Pass a custom coordinator by subclassing `UIViewBridgeCoordinator<T>` and pass an
  /// instance of it to `createCoordinatorClosure`
  public var coordinator: UIViewBridgeCoordinator<T>?

  /// View configuration closure.
  private let _configureClosure: (T, Context) -> Void

  init(
    createInstanceClosure: () -> T = { T() },
    createCoordinatorClosure: (Self) -> Coordinator = { Coordinator(bridge: $0) },
    configureClosure: @escaping (T, Context) -> Void
  ) {
    self.view = createInstanceClosure()
    self._configureClosure = configureClosure
    self.coordinator = createCoordinatorClosure(self)
  }

  /// MARK: - UIViewRepresentable

  public func makeUIView(context: Context) -> T {
    view
  }

  public func updateUIView(_ uiView: T, context: Context) {
    _configureClosure(uiView, context)
    self.coordinator?.bridge = self
  }

  public func makeCoordinator() -> UIViewBridgeCoordinator<T> {
    coordinator!
  }
}

// MARK: - UIViewBridgeCoordinator

open class UIViewBridgeCoordinator<T: UIView>: NSObject {
  /// A copy of the view wrapped (updated at the latest `updateUIView(_:context)`).
  public var bridge: UIViewBridge<T>

  public init(bridge: UIViewBridge<T>) {
    self.bridge = bridge
  }
}