Merge pull request #5 from bullinnyc/add-image-cache-protocol

Add image cache protocol.

Examples/ContentView.swift

@@ -102,7 +102,7 @@ struct ContentView: View {
 
     init() {
         // Set image cache limit.
-        TemporaryImageCache.shared.setCacheLimit(
+        Environment(\.imageCache).wrappedValue.setCacheLimit(
             countLimit: 1000, // 1000 items
             totalCostLimit: 1024 * 1024 * 200 // 200 MB
         )

README.md

@@ -97,11 +97,13 @@ CachedAsyncImage(
 **Note:** The default value is `0`, e.g. is no count limit and is no total cost limit.
 
 ```swift
-// Set image cache limit.
-TemporaryImageCache.shared.setCacheLimit(
-    countLimit: 1000, // 1000 items
-    totalCostLimit: 1024 * 1024 * 200 // 200 MB
-)
+init() {
+    // Set image cache limit.
+    Environment(\.imageCache).wrappedValue.setCacheLimit(
+        countLimit: 1000, // 1000 items
+        totalCostLimit: 1024 * 1024 * 200 // 200 MB
+    )
+}
 ```
 
 ## Requirements

Sources/CachedAsyncImage/EnvironmentValues/EnvironmentValues + ImageCache.swift

@@ -0,0 +1,33 @@
+//
+//  EnvironmentValues + ImageCache.swift
+//  CachedAsyncImage
+//
+//  Created by Dmitry Kononchuk on 02.01.2024.
+//  Copyright © 2024 Dmitry Kononchuk. All rights reserved.
+//
+
+import SwiftUI
+
+struct ImageCacheKey: EnvironmentKey {
+    // MARK: - Public Properties
+
+    static let defaultValue: ImageCache = TempImageCache()
+}
+
+extension EnvironmentValues {
+    // MARK: - Public Properties
+
+    /// The image cache of this environment.
+    ///
+    /// Read this environment value from within a view to access the image cache management.
+    ///
+    ///     struct MyView: View {
+    ///         @Environment(\.imageCache) private var imageCache
+    ///
+    ///         // ...
+    ///     }
+    public var imageCache: ImageCache {
+        get { self[ImageCacheKey.self] }
+        set { self[ImageCacheKey.self] = newValue }
+    }
+}

Sources/CachedAsyncImage/EnvironmentValues/EnvironmentValues + NetworkManager.swift

@@ -0,0 +1,24 @@
+//
+//  EnvironmentValues + NetworkManager.swift
+//  CachedAsyncImage
+//
+//  Created by Dmitry Kononchuk on 02.01.2024.
+//  Copyright © 2024 Dmitry Kononchuk. All rights reserved.
+//
+
+import SwiftUI
+
+struct NetworkManagerKey: EnvironmentKey {
+    // MARK: - Public Properties
+
+    static let defaultValue: NetworkManagerProtocol = NetworkManager()
+}
+
+extension EnvironmentValues {
+    // MARK: - Public Properties
+
+    var networkManager: NetworkManagerProtocol {
+        get { self[NetworkManagerKey.self] }
+        set { self[NetworkManagerKey.self] = newValue }
+    }
+}

Sources/CachedAsyncImage/Services/ImageLoader.swift

@@ -19,7 +19,7 @@ final class ImageLoader: ObservableObject {
     // MARK: - Private Properties
 
     private let networkManager: NetworkManagerProtocol
-    private let imageCache = TemporaryImageCache.shared
+    private var imageCache: ImageCache
 
     private var cancellables: Set<AnyCancellable> = []
     private(set) var isLoading = false
@@ -30,8 +30,9 @@ final class ImageLoader: ObservableObject {
 
     // MARK: - Initializers
 
-    init(networkManager: NetworkManagerProtocol) {
+    init(networkManager: NetworkManagerProtocol, imageCache: ImageCache) {
         self.networkManager = networkManager
+        self.imageCache = imageCache
     }
 
     // MARK: - Deinitializers

Sources/CachedAsyncImage/Services/NetworkManager.swift

@@ -39,15 +39,7 @@ protocol NetworkManagerProtocol {
     )
 }
 
-final class NetworkManager: NetworkManagerProtocol {
-    // MARK: - Public Properties
-
-    static let shared = NetworkManager()
-
-    // MARK: - Private Initializers
-
-    private init() {}
-
+struct NetworkManager: NetworkManagerProtocol {
     // MARK: - Public Methods
 
     func fetchImage(from url: URL?) -> (

Sources/CachedAsyncImage/Services/TempImageCache.swift

@@ -0,0 +1,61 @@
+//
+//  TempImageCache.swift
+//  CachedAsyncImage
+//
+//  Created by Dmitry Kononchuk on 02.01.2024.
+//  Copyright © 2024 Dmitry Kononchuk. All rights reserved.
+//
+
+import Foundation
+
+/// Image cache protocol.
+public protocol ImageCache {
+    subscript(_ url: URL) -> CPImage? { get set }
+
+    /// Set cache limit.
+    ///
+    /// - Parameters:
+    ///   - countLimit: The maximum number of objects the cache should hold.
+    ///   If `0`, there is no count limit. The default value is `0`.
+    ///   - totalCostLimit: The maximum total cost that the cache can hold before
+    ///   it starts evicting objects.
+    ///   When you add an object to the cache, you may pass in a specified cost for the object,
+    ///   such as the size in bytes of the object.
+    ///   If `0`, there is no total cost limit. The default value is `0`.
+    func setCacheLimit(countLimit: Int, totalCostLimit: Int)
+
+    /// Empties the cache.
+    func removeCache()
+}
+
+/// Temporary image cache.
+struct TempImageCache: ImageCache {
+    // MARK: - Private Properties
+
+    private let cache: NSCache<NSURL, CPImage> = {
+        let cache = NSCache<NSURL, CPImage>()
+        return cache
+    }()
+
+    // MARK: - Subscripts
+
+    public subscript(_ key: URL) -> CPImage? {
+        get { cache.object(forKey: key as NSURL) }
+        set {
+            newValue == nil
+                ? cache.removeObject(forKey: key as NSURL)
+                : cache.setObject(newValue ?? CPImage(), forKey: key as NSURL)
+        }
+    }
+
+    // MARK: - Public Methods
+
+    public func setCacheLimit(countLimit: Int = 0, totalCostLimit: Int = 0) {
+        cache.countLimit = countLimit
+        cache.totalCostLimit = totalCostLimit
+    }
+
+    public func removeCache() {
+        cache.removeAllObjects()
+    }
+}

Sources/CachedAsyncImage/Services/TemporaryImageCache.swift

@@ -8,8 +8,16 @@
 
 import Foundation
 
+/// Will be removed in future versions.
+var isTemporaryImageCacheInitialized = false
+
 /// Temporary image cache.
-public final class TemporaryImageCache {
+@available(
+    *,
+    deprecated,
+    message: "Will be removed in future versions. Use Environment with key path 'imageCache' property."
+)
+public final class TemporaryImageCache: ImageCache {
     // MARK: - Public Properties
 
     /// The singleton instance.
@@ -19,14 +27,14 @@ public final class TemporaryImageCache {
 
     // MARK: - Private Properties
 
-    private lazy var cache: NSCache<NSURL, CPImage> = {
+    private let cache: NSCache<NSURL, CPImage> = {
         let cache = NSCache<NSURL, CPImage>()
         return cache
     }()
 
     // MARK: - Subscripts
 
-    subscript(_ key: URL) -> CPImage? {
+    public subscript(_ key: URL) -> CPImage? {
         get { cache.object(forKey: key as NSURL) }
         set {
             newValue == nil
@@ -37,26 +45,17 @@ public final class TemporaryImageCache {
 
     // MARK: - Private Initializers
 
-    private init() {}
+    private init() {
+        isTemporaryImageCacheInitialized = true
+    }
 
     // MARK: - Public Methods
 
-    /// Set cache limit.
-    ///
-    /// - Parameters:
-    ///   - countLimit: The maximum number of objects the cache should hold.
-    ///   If `0`, there is no count limit. The default value is `0`.
-    ///   - totalCostLimit: The maximum total cost that the cache can hold before
-    ///   it starts evicting objects.
-    ///   When you add an object to the cache, you may pass in a specified cost for the object,
-    ///   such as the size in bytes of the object.
-    ///   If `0`, there is no total cost limit. The default value is `0`.
     public func setCacheLimit(countLimit: Int = 0, totalCostLimit: Int = 0) {
         cache.countLimit = countLimit
         cache.totalCostLimit = totalCostLimit
     }
 
-    /// Empties the cache.
     public func removeCache() {
         cache.removeAllObjects()
     }

Sources/CachedAsyncImage/Views/CachedAsyncImage.swift

@@ -52,7 +52,10 @@ public struct CachedAsyncImage: View {
         error: ((String) -> any View)? = nil
     ) {
         _imageLoader = StateObject(
-            wrappedValue: ImageLoader(networkManager: NetworkManager.shared)
+            wrappedValue: ImageLoader(
+                networkManager: Environment(\.networkManager).wrappedValue,
+                imageCache: CachedAsyncImage.getImageCache()
+            )
         )
 
         self.url = url
@@ -75,7 +78,10 @@ public struct CachedAsyncImage: View {
         error: ((String) -> any View)? = nil
     ) {
         _imageLoader = StateObject(
-            wrappedValue: ImageLoader(networkManager: NetworkManager.shared)
+            wrappedValue: ImageLoader(
+                networkManager: Environment(\.networkManager).wrappedValue,
+                imageCache: CachedAsyncImage.getImageCache()
+            )
         )
 
         self.url = url
@@ -98,7 +104,10 @@ public struct CachedAsyncImage: View {
         error: ((String) -> any View)? = nil
     ) {
         _imageLoader = StateObject(
-            wrappedValue: ImageLoader(networkManager: NetworkManager.shared)
+            wrappedValue: ImageLoader(
+                networkManager: Environment(\.networkManager).wrappedValue,
+                imageCache: CachedAsyncImage.getImageCache()
+            )
         )
 
         self.url = url
@@ -108,6 +117,17 @@ public struct CachedAsyncImage: View {
 
         placeholderWithProgress = placeholder
     }
+
+    // MARK: - Private Methods
+
+    /// Will be removed in future versions.
+    private static func getImageCache() -> ImageCache {
+        if isTemporaryImageCacheInitialized {
+            TemporaryImageCache.shared
+        } else {
+            Environment(\.imageCache).wrappedValue
+        }
+    }
 }
 
 // MARK: - Ext. Configure views

Tests/CachedAsyncImageTests/ImageLoaderTests.swift

@@ -28,11 +28,14 @@ final class ImageLoaderTests: XCTestCase {
     func testFetchImage_WithCachedImage() {
         // Given
         let url = "https://example.com/image.jpg"
-        let networkManager = sut.networkManager
-        let imageCache = sut.imageCache
         let cachedImage = RM.image("backToTheFuture")
+        let networkManager = sut.networkManager
+        var imageCache = sut.imageCache
 
-        let imageLoader = ImageLoader(networkManager: networkManager)
+        let imageLoader = ImageLoader(
+            networkManager: networkManager,
+            imageCache: imageCache
+        )
 
         // When
         guard let imageUrl = URL(string: url) else {
@@ -58,10 +61,14 @@ final class ImageLoaderTests: XCTestCase {
         // Given
         let url = "https://example.com/image.jpg"
         let networkManager = sut.networkManager
+
         let imageCache = sut.imageCache
         imageCache.removeCache()
 
-        let imageLoader = ImageLoader(networkManager: networkManager)
+        let imageLoader = ImageLoader(
+            networkManager: networkManager,
+            imageCache: imageCache
+        )
 
         // When
         imageLoader.fetchImage(from: url)
@@ -117,12 +124,12 @@ final class ImageLoaderTests: XCTestCase {
 extension ImageLoaderTests {
     typealias Sut = (
         networkManager: NetworkManagerProtocol,
-        imageCache: TemporaryImageCache
+        imageCache: ImageCache
     )
 
     private func makeSUT() -> Sut {
-        let networkManager = NetworkManagerMock.shared
-        let imageCache = TemporaryImageCache.shared
+        let networkManager = NetworkManagerMock()
+        let imageCache = TempImageCache()
 
         return (networkManager, imageCache)
     }

Tests/CachedAsyncImageTests/Mocks/NetworkManagerMock.swift

@@ -10,15 +10,7 @@ import Foundation
 import Combine
 @testable import CachedAsyncImage
 
-final class NetworkManagerMock: NetworkManagerProtocol {
-    // MARK: - Public Properties
-
-    static let shared = NetworkManagerMock()
-
-    // MARK: - Private Initializers
-
-    private init() {}
-
+struct NetworkManagerMock: NetworkManagerProtocol {
     // MARK: - Public Methods
 
     func fetchImage(from url: URL?) -> (