Xcode 14, iOS 16 SDK (min iOS 13)

Demo/Sources/Helpers/ImageDownloader.swift

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+//
+// Demo
+// Copyright © 2020 John Rommel Estropia, Inc. All rights reserved.
+
+import Foundation
+import UIKit
+import Combine
+
+// MARK: - ImageDownloader
+
+final class ImageDownloader: ObservableObject {
+    
+    // MARK: FilePrivate
+    
+    private(set) var image: UIImage?
+    
+    let url: URL?
+    
+    init(url: URL?) {
+        
+        self.url = url
+        guard let url = url else {
+            
+            return
+        }
+        if let image = Self.cache[url] {
+            
+            self.image = image
+        }
+    }
+    
+    func fetchImage(completion: @escaping (UIImage) -> Void = { _ in }) {
+        
+        guard let url = url else {
+            
+            return
+        }
+        if let image = Self.cache[url] {
+            
+            self.objectWillChange.send()
+            self.image = image
+            completion(image)
+            return
+        }
+        self.cancellable = URLSession.shared
+            .dataTaskPublisher(for: url)
+            .receive(on: DispatchQueue.main)
+            .sink(
+                receiveCompletion: { _ in },
+                receiveValue: { output in
+                    
+                    if let image = UIImage(data: output.data) {
+                        
+                        Self.cache[url] = image
+                        self.objectWillChange.send()
+                        self.image = image
+                        completion(image)
+                    }
+                }
+            )
+    }
+    
+    
+    // MARK: Private
+    
+    private static var cache: [URL: UIImage] = [:]
+    
+    private var cancellable: AnyCancellable?
+}