fix image loading

TMDB/Sources/Screens/Search/MovieTableViewCell.swift

@@ -17,32 +17,19 @@ class MovieTableViewCell: UITableViewCell, NibProvidable, ReusableView {
     @IBOutlet private var poster: UIImageView!
     private var cancellable: AnyCancellable?
 
-    override func prepareForReuse() {
-        super.prepareForReuse()
-        cancelImageLoading()
-    }
-
     func bind(to viewModel: MovieViewModel) {
         cancelImageLoading()
         title.text = viewModel.title
         subtitle.text = viewModel.subtitle
         rating.text = viewModel.rating
-        cancellable = viewModel.poster.sink { [unowned self] image in self.showImage(image: image) }
+
+        cancellable = viewModel.poster
+          .receive(on: DispatchQueue.main)
+          .assign(to: \.poster.image, on: self)
     }
-
-    private func showImage(image: UIImage?) {
-        cancelImageLoading()
-        UIView.transition(with: self.poster,
-        duration: 0.3,
-        options: [.curveEaseOut, .transitionCrossDissolve],
-        animations: {
-            self.poster.image = image
-        })
-    }
-
-    private func cancelImageLoading() {
-        poster.image = nil
-        cancellable?.cancel()
-    }
-
+
+  private func cancelImageLoading() {
+      poster.image = nil
+      cancellable?.cancel()
+  }
 }

TMDB/Sources/Services/ImageLoader/ImageLoaderService.swift

@@ -11,21 +11,23 @@ import UIKit.UIImage
 import Combine
 
 final class ImageLoaderService: ImageLoaderServiceType {
-
+    
     private let cache: ImageCacheType = ImageCache()
-
-    func loadImage(from url: URL) -> AnyPublisher<UIImage?, Never> {
+    
+    func loadImage(from url: URL, placeholder: UIImage? = nil) -> AnyPublisher<UIImage?, Never> {
         if let image = cache.image(for: url) {
             return .just(image)
         }
         return URLSession.shared.dataTaskPublisher(for: url)
-            .map { (data, response) -> UIImage? in return UIImage(data: data) }
-            .catch { error in return Just(nil) }
-            .handleEvents(receiveOutput: {[unowned self] image in
-                guard let image = image else { return }
+            .tryMap { data, response -> UIImage in
+                guard let image = UIImage(data: data) else {
+                    throw NSError(domain: "", code: 1, userInfo: nil)
+                }
+
                 self.cache.insertImage(image, for: url)
-            })
-            .print("Image loading \(url):")
+                return image
+            }
+            .replaceError(with: placeholder)
             .eraseToAnyPublisher()
     }
 }

TMDB/Sources/Services/ImageLoader/ImageLoaderServiceType.swift

@@ -11,5 +11,5 @@ import UIKit.UIImage
 import Combine
 
 protocol ImageLoaderServiceType: AnyObject, AutoMockable {
-    func loadImage(from url: URL) -> AnyPublisher<UIImage?, Never>
+    func loadImage(from url: URL, placeholder: UIImage?) -> AnyPublisher<UIImage?, Never>
 }

TMDB/Sources/UseCases/MoviesUseCase.swift

@@ -53,16 +53,19 @@ final class MoviesUseCase: MoviesUseCaseType {
     }
 
     func loadImage(for movie: Movie, size: ImageSize) -> AnyPublisher<UIImage?, Never> {
-        return Deferred { return Just(movie.poster) }
-        .flatMap({[unowned self] poster -> AnyPublisher<UIImage?, Never> in
-            guard let poster = movie.poster else { return .just(nil) }
-            let url = size.url.appendingPathComponent(poster)
-            return self.imageLoaderService.loadImage(from: url)
-        })
-        .subscribe(on: Scheduler.backgroundWorkScheduler)
-        .receive(on: Scheduler.mainScheduler)
-        .share()
-        .eraseToAnyPublisher()
+        guard let poster = movie.poster else { return .just(nil) }
+        let url = size.url.appendingPathComponent(poster)
+        return imageLoaderService.loadImage(from: url, placeholder: imageFrom(color: .gray))
+    }
+
+    func imageFrom(color: UIColor) -> UIImage {
+        let rect = CGRect(x: 0, y: 0, width: 1, height: 1)
+        UIGraphicsBeginImageContext(rect.size)
+        let context = UIGraphicsGetCurrentContext()
+        context!.setFillColor(color.cgColor)
+        context!.fill(rect)
+        let img = UIGraphicsGetImageFromCurrentImageContext()
+        UIGraphicsEndImageContext()
+        return img!
     }
-
 }