UIControl extension to bind events to blocks (iOS 14+)

Author: ivkosh

Sources/CoreUI/UIControl+onEvent.swift

@@ -0,0 +1,83 @@
+import UIKit
+
+@available(iOS 14.0, *)
+public extension UIControl {
+
+    /// Adds `action` block to `self` to run for specified `event`.
+    ///
+    /// - Parameters:
+    ///   - event: UIControl.Event to react on
+    ///   - action: block to run for `event`
+    /// - Returns: self
+    func on(_ event: UIControl.Event, do action: @escaping () -> Void) -> Self {
+        addAction(
+            UIAction { _ in
+                action()
+            },
+            for: event
+        )
+        return self
+    }
+
+    /// Adds async `action` block to `self` to run for specified `event`.
+    ///
+    /// - Parameters:
+    ///   - event: UIControl.Event to react on
+    ///   - action: async block to run for `event`
+    /// - Returns: self
+    ///
+    /// Action will be started concurrently in cooperative thread pool. It would not inherit parent's actor.
+    /// If you need to run block's code with specific actor/queue you should take care of it by yourself.
+    /// E.g. if you'll need to run some code on MainActor you should wrap it with `MainActor.run` or annotate function called from block with @MainActor.
+    /// 
+    /// NB: Adding @MainActor annotation to `action` block will be not enough!
+    ///
+    /// # Example:
+    ///
+    ///     // MyViewController
+    ///     override func viewDidLoad() {
+    ///         // ...
+    ///         addSubview(
+    ///             UI.VStack(
+    ///                 UIButton()
+    ///                     .apply { $0.setTitle("First button", for: .normal) }
+    ///                     .on(.touchUpInside, do: viewModel.firstButtonTapped),
+    ///                 UIButton()
+    ///                     .apply { $0.setTitle("Second button", for: .normal) }
+    ///                     .on(.touchUpInside) { [unowned self] in await viewModel.secondButtonTapped() }
+    ///             ),
+    ///             padding: 20
+    ///         )
+    ///         // ...
+    ///     }
+    ///
+    ///     // MyViewModel
+    ///     @MainActor
+    ///     func firstButtonTapped() async {
+    ///         // code from this funciton will run on MainActor
+    ///     }
+    ///
+    ///     func secondButtonTapped() async {
+    ///         // following code will NOT run on MainActor
+    ///         doSomethingSync()
+    ///         await doSomethingAsync()
+    ///
+    ///         await MainActor.run {
+    ///             updateUI() // syncronous func will run on MainActor
+    ///         }
+    ///     }
+    ///
+    func on(_ event: UIControl.Event, do action: @escaping () async -> Void) -> Self {
+        addAction(
+            UIAction { _ in
+                Task {
+                    // NB: action does not run on MainActor!
+                    await action()
+                }
+            },
+            for: event
+        )
+        return self
+    }
+
+}