Fix the WebImage onSuccess does not get called because of StateObject get touched before onAppear

Author: dreampiggy

SDWebImageSwiftUI/Classes/WebImage.swift

@@ -9,21 +9,46 @@
 import SwiftUI
 import SDWebImage
 
+/// Completion Handler Binding Object, supports dynamic @State changes
+@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
+final class WebImageHandler: ObservableObject {
+    // Completion Handler
+    @Published var successBlock: ((PlatformImage, Data?, SDImageCacheType) -> Void)?
+    @Published var failureBlock: ((Error) -> Void)?
+    @Published var progressBlock: ((Int, Int) -> Void)?
+}
+
+/// Configuration Binding Object, supports dynamic @State changes
+@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
+final class WebImageConfiguration: ObservableObject {
+    var retryOnAppear: Bool = true
+    var cancelOnDisappear: Bool = true
+    var maxBufferSize: UInt?
+    var customLoopCount: UInt?
+    var runLoopMode: RunLoop.Mode = .common
+    var pausable: Bool = true
+    var purgeable: Bool = false
+    var playbackRate: Double = 1.0
+    var playbackMode: SDAnimatedImagePlaybackMode = .normal
+}
+
 /// A Image View type to load image from url. Supports static/animated image format.
 @available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
 public struct WebImage : View {
     var configurations: [(Image) -> Image] = []
 
     var placeholder: AnyView?
-    var retryOnAppear: Bool = true
-    var cancelOnDisappear: Bool = true
-    var pausable: Bool = true
-    var purgeable: Bool = false
 
     /// A Binding to control the animation. You can bind external logic to control the animation status.
     /// True to start animation, false to stop animation.
     @Binding public var isAnimating: Bool
 
+    /// A observed object to pass through the image handler to manager
+    @ObservedObject var imageHandler = WebImageHandler()
+    
+    /// A observed object to pass through the image configuration to player
+    @ObservedObject var imageConfiguration = WebImageConfiguration()
+    
     /// A observed object to pass through the image manager loading status to indicator
     @ObservedObject var indicatorStatus = IndicatorStatus()
 
@@ -84,12 +109,12 @@ public struct WebImage : View {
                     .onDisappear {
                         // Only stop the player which is not intermediate status
                         if !imagePlayer.isWaiting {
-                            if self.pausable {
+                            if self.imageConfiguration.pausable {
                                 self.imagePlayer.pausePlaying()
                             } else {
                                 self.imagePlayer.stopPlaying()
                             }
-                            if self.purgeable {
+                            if self.imageConfiguration.purgeable {
                                 self.imagePlayer.clearFrameBuffer()
                             }
                         }
@@ -104,15 +129,18 @@ public struct WebImage : View {
             } else {
                 setupPlaceholder()
                 .onAppear {
+                    self.imageManager.successBlock = self.imageHandler.successBlock
+                    self.imageManager.failureBlock = self.imageHandler.failureBlock
+                    self.imageManager.progressBlock = self.imageHandler.progressBlock
                     // Load remote image when first appear
                     self.imageManager.load()
-                    guard self.retryOnAppear else { return }
+                    guard self.imageConfiguration.retryOnAppear else { return }
                     // When using prorgessive loading, the new partial image will cause onAppear. Filter this case
                     if self.imageManager.image == nil && !self.imageManager.isIncremental {
                         self.imageManager.load()
                     }
                 }.onDisappear {
-                    guard self.cancelOnDisappear else { return }
+                    guard self.imageConfiguration.cancelOnDisappear else { return }
                     // When using prorgessive loading, the previous partial image will cause onDisappear. Filter this case
                     if self.imageManager.image == nil && !self.imageManager.isIncremental {
                         self.imageManager.cancel()
@@ -183,6 +211,11 @@ public struct WebImage : View {
         } else {
             return configure(image: imageManager.image!).onAppear {
                 if let animatedImage = imageManager.image as? SDAnimatedImageProvider {
+                    self.imagePlayer.customLoopCount = self.imageConfiguration.customLoopCount
+                    self.imagePlayer.maxBufferSize = self.imageConfiguration.maxBufferSize
+                    self.imagePlayer.runLoopMode = self.imageConfiguration.runLoopMode
+                    self.imagePlayer.playbackMode = self.imageConfiguration.playbackMode
+                    self.imagePlayer.playbackRate = self.imageConfiguration.playbackRate
                     self.imagePlayer.setupPlayer(animatedImage: animatedImage)
                     self.imagePlayer.startPlaying()
                 }
@@ -253,7 +286,7 @@ extension WebImage {
     ///   - action: The action to perform. The first arg is the error during loading. If `action` is `nil`, the call has no effect.
     /// - Returns: A view that triggers `action` when this image load fails.
     public func onFailure(perform action: ((Error) -> Void)? = nil) -> WebImage {
-        self.imageManager.failureBlock = action
+        self.imageHandler.failureBlock = action
         return self
     }
 
@@ -262,7 +295,7 @@ extension WebImage {
     ///   - action: The action to perform. The first arg is the loaded image, the second arg is the loaded image data, the third arg is the cache type loaded from. If `action` is `nil`, the call has no effect.
     /// - Returns: A view that triggers `action` when this image load successes.
     public func onSuccess(perform action: ((PlatformImage, Data?, SDImageCacheType) -> Void)? = nil) -> WebImage {
-        self.imageManager.successBlock = action
+        self.imageHandler.successBlock = action
         return self
     }
 
@@ -271,7 +304,7 @@ extension WebImage {
     ///   - action: The action to perform. The first arg is the received size, the second arg is the total size, all in bytes. If `action` is `nil`, the call has no effect.
     /// - Returns: A view that triggers `action` when this image load successes.
     public func onProgress(perform action: ((Int, Int) -> Void)? = nil) -> WebImage {
-        self.imageManager.progressBlock = action
+        self.imageHandler.progressBlock = action
         return self
     }
 }
@@ -303,17 +336,15 @@ extension WebImage {
     /// Control the behavior to retry the failed loading when view become appears again
     /// - Parameter flag: Whether or not to retry the failed loading
     public func retryOnAppear(_ flag: Bool) -> WebImage {
-        var result = self
-        result.retryOnAppear = flag
-        return result
+        self.imageConfiguration.retryOnAppear = flag
+        return self
     }
 
     /// Control the behavior to cancel the pending loading when view become disappear again
     /// - Parameter flag: Whether or not to cancel the pending loading
     public func cancelOnDisappear(_ flag: Bool) -> WebImage {
-        var result = self
-        result.cancelOnDisappear = flag
-        return result
+        self.imageConfiguration.cancelOnDisappear = flag
+        return self
     }
 }
 
@@ -342,7 +373,7 @@ extension WebImage {
     /// - Note: Pass nil to disable customization, use the image itself loop count (`animatedImageLoopCount`) instead
     /// - Parameter loopCount: The animation loop count
     public func customLoopCount(_ loopCount: UInt?) -> WebImage {
-        self.imagePlayer.customLoopCount = loopCount
+        self.imageConfiguration.customLoopCount = loopCount
         return self
     }
 
@@ -353,7 +384,7 @@ extension WebImage {
     /// `UInt.max` means cache all the buffer. (Lowest CPU and Highest Memory)
     /// - Parameter bufferSize: The max buffer size
     public func maxBufferSize(_ bufferSize: UInt?) -> WebImage {
-        self.imagePlayer.maxBufferSize = bufferSize
+        self.imageConfiguration.maxBufferSize = bufferSize
         return self
     }
 
@@ -362,26 +393,24 @@ extension WebImage {
     /// - Note: This is useful for some cases, for example, always specify NSDefaultRunLoopMode, if you want to pause the animation when user scroll (for Mac user, drag the mouse or touchpad)
     /// - Parameter runLoopMode: The runLoopMode for animation
     public func runLoopMode(_ runLoopMode: RunLoop.Mode) -> WebImage {
-        self.imagePlayer.runLoopMode = runLoopMode
+        self.imageConfiguration.runLoopMode = runLoopMode
         return self
     }
 
     /// Whether or not to pause the animation (keep current frame), instead of stop the animation (frame index reset to 0). When `isAnimating` binding value changed to false. Defaults is true.
     /// - Note: For some of use case, you may want to reset the frame index to 0 when stop, but some other want to keep the current frame index.
     /// - Parameter pausable: Whether or not to pause the animation instead of stop the animation.
     public func pausable(_ pausable: Bool) -> WebImage {
-        var result = self
-        result.pausable = pausable
-        return result
+        self.imageConfiguration.pausable = pausable
+        return self
     }
 
     /// Whether or not to clear frame buffer cache when stopped. Defaults is false.
     /// Note: This is useful when you want to limit the memory usage during frequently visibility changes (such as image view inside a list view, then push and pop)
     /// - Parameter purgeable: Whether or not to clear frame buffer cache when stopped.
     public func purgeable(_ purgeable: Bool) -> WebImage {
-        var result = self
-        result.purgeable = purgeable
-        return result
+        self.imageConfiguration.purgeable = purgeable
+        return self
     }
 
     /// Control the animation playback rate. Default is 1.0.
@@ -392,14 +421,14 @@ extension WebImage {
     /// `< 0.0` is not supported currently and stop animation. (may support reverse playback in the future)
     /// - Parameter playbackRate: The animation playback rate.
     public func playbackRate(_ playbackRate: Double) -> WebImage {
-        self.imagePlayer.playbackRate = playbackRate
+        self.imageConfiguration.playbackRate = playbackRate
         return self
     }
 
     /// Control the animation playback mode. Default is .normal
     /// - Parameter playbackMode: The playback mode, including normal order, reverse order, bounce order and reversed bounce order.
     public func playbackMode(_ playbackMode: SDAnimatedImagePlaybackMode) -> WebImage {
-        self.imagePlayer.playbackMode = playbackMode
+        self.imageConfiguration.playbackMode = playbackMode
         return self
     }
 }