feat: TextField keypath publisher

Author: DominikPetho

Sources/GoodCombineExtensions/UIKit/UIControlPublisher.swift

@@ -45,3 +45,50 @@ public extension GRActive where Base: UIControl {
 
 }
 
+// MARK: - Keypath Publisher
+
+@available(iOS 13.0, *)
+public extension Combine.Publishers {
+
+    /// A Control Property is a publisher that emits the value at the provided keypath
+    /// whenever the specific control events are triggered. It also emits the keypath's
+    /// initial value upon subscription.
+    struct ControlProperty<Control: UIControl, Value>: Publisher {
+
+        public typealias Output = Value
+        public typealias Failure = Never
+
+        private let control: Control
+        private let controlEvents: Control.Event
+        private let keyPath: KeyPath<Control, Value>
+
+        /// Initialize a publisher that emits the value at the specified keypath
+        /// whenever any of the provided Control Events trigger.
+        ///
+        /// - parameter control: UI Control.
+        /// - parameter events: Control Events.
+        /// - parameter keyPath: A Key Path from the UI Control to the requested value.
+        public init(
+            control: Control,
+            events: Control.Event,
+            keyPath: KeyPath<Control, Value>
+        ) {
+            self.control = control
+            self.controlEvents = events
+            self.keyPath = keyPath
+        }
+
+        public func receive<S: Subscriber>(subscriber: S) where S.Failure == Failure, S.Input == Output {
+            let subscription = UIControlKeyPathSubscription(
+                subscriber: subscriber,
+                control: control,
+                event: controlEvents,
+                keyPath: keyPath
+            )
+
+            subscriber.receive(subscription: subscription)
+        }
+
+    }
+
+}

Sources/GoodCombineExtensions/UIKit/UIControlSubscriber.swift

@@ -37,3 +37,49 @@ final public class UIControlSubscription<SubscriberType: Subscriber, Control: UI
         _ = subscriber?.receive(control)
     }
 }
+
+// swiftlint:disable line_length
+@available(iOS 13.0, *)
+public final class UIControlKeyPathSubscription<S: Subscriber, Control: UIControl, Value>: Combine.Subscription where S.Input == Value {
+// swiftlint:enable line_length
+
+    private var subscriber: S?
+    weak private var control: Control?
+    let keyPath: KeyPath<Control, Value>
+    private var didEmitInitial = false
+    private let event: Control.Event
+
+    init(subscriber: S, control: Control, event: Control.Event, keyPath: KeyPath<Control, Value>) {
+        self.subscriber = subscriber
+        self.control = control
+        self.keyPath = keyPath
+        self.event = event
+        control.addTarget(self, action: #selector(handleEvent), for: event)
+    }
+
+    public func request(_ demand: Subscribers.Demand) {
+        // Emit initial value upon first demand request
+        if !didEmitInitial,
+            demand > .none,
+            let control = control,
+            let subscriber = subscriber {
+            _ = subscriber.receive(control[keyPath: keyPath])
+            didEmitInitial = true
+        }
+
+        // We don't care about the demand at this point.
+        // As far as we're concerned - UIControl events are endless until the control is deallocated.
+    }
+
+    public func cancel() {
+        control?.removeTarget(self, action: #selector(handleEvent), for: event)
+        subscriber = nil
+    }
+
+    @objc private func handleEvent() {
+        guard let control = control else { return }
+
+        _ = subscriber?.receive(control[keyPath: keyPath])
+    }
+
+}

Sources/GoodCombineExtensions/UIKit/UISwitchPublisher.swift

@@ -0,0 +1,19 @@
+//
+//  UISwitchCombineExtension.swift
+//  
+//
+//  Created by Andrej Jasso on 11/03/2022.
+//
+
+import Combine
+import GRCompatible
+import UIKit
+
+public extension GRActive where Base: UISwitch {
+
+    var isOnPublisher: AnyPublisher<Bool, Never> {
+        Publishers.ControlProperty(control: base, events: .valueChanged, keyPath: \.isOn)
+            .eraseToAnyPublisher()
+    }
+
+}

Sources/GoodCombineExtensions/UIKit/UITextfieldPublisher.swift

@@ -0,0 +1,35 @@
+//
+//  UITextFieldPublisher.swift
+//  
+//
+//  Created by Andrej Jasso on 10/03/2022.
+//
+
+import Combine
+import GRCompatible
+import UIKit
+
+@available(iOS 13.0, *)
+public struct UITextFieldPublisher<TextField: UITextField>: Publisher {
+
+    public typealias Output = TextField
+    public typealias Failure = Never
+
+    weak var textfield: TextField?
+    let event: UITextField.Event
+
+    init(control: TextField, event: UIControl.Event) {
+        self.textfield = control
+        self.event = event
+    }
+
+    public func receive<S>(subscriber: S) where S: Subscriber, Never == S.Failure, TextField == S.Input {
+        let subscription = UITextFieldSubscription(
+            subscriber: subscriber,
+            textfield: textfield,
+            event: event
+        )
+        subscriber.receive(subscription: subscription)
+    }
+
+}

Sources/GoodCombineExtensions/UIKit/UITextfieldSubscriber.swift

@@ -0,0 +1,54 @@
+//
+//  UITextFieldSubscriber.swift
+//  
+//
+//  Created by Andrej Jasso on 11/03/2022.
+//
+
+import Combine
+import GRCompatible
+import UIKit
+
+// swiftlint:disable line_length
+@available(iOS 13.0, *)
+final public class UITextFieldSubscription<SubscriberType: Subscriber, TextField: UITextField>: Subscription where SubscriberType.Input == TextField {
+// swiftlint:enable line_length
+
+    private var subscriber: SubscriberType?
+    private weak var textfield: TextField?
+
+    init(subscriber: SubscriberType, textfield: TextField?, event: UITextField.Event) {
+        self.subscriber = subscriber
+        self.textfield = textfield
+
+        textfield?.addTarget(self, action: #selector(eventHandler), for: event)
+    }
+
+    public func request(_ demand: Subscribers.Demand) {}
+
+    public func cancel() {
+        subscriber = nil
+    }
+
+    @objc private func eventHandler() {
+        guard let textfield = textfield else { return }
+        _ = subscriber?.receive(textfield)
+    }
+}
+
+public extension GRActive where Base: UITextField {
+
+    func eventPublisher(for event: UIControl.Event) -> UITextFieldPublisher<UITextField> {
+        UITextFieldPublisher(control: base, event: event)
+    }
+
+}
+
+public extension GRActive where Base: UITextField {
+
+    var textPublisher: AnyPublisher<String?, Never> {
+        Publishers.ControlProperty(control: base, events: [.valueChanged, .allEditingEvents], keyPath: \.text)
+            .eraseToAnyPublisher()
+    }
+
+}

Sources/GoodExtensions/Foundation/DateExtentions.swift

@@ -1,6 +1,6 @@
 //
-//  DateExtensions.swift
-//  GoodExtensions
+//  Date.swift
+//
 //
 //  Created by Andrej Jasso on 08/06/2021.
 //  Copyright © 2020 GoodRequest. All rights reserved.