Code garden with Xcode 12's if let syntax in function builder

Author: dreampiggy

SDWebImageSwiftUI/Classes/ImagePlayer.swift

@@ -78,7 +78,8 @@ public final class ImagePlayer : ObservableObject {
         player?.clearFrameBuffer()
     }
 
-    /// Setup the player using Animated Image
+    /// Setup the player using Animated Image.
+    /// After setup, you can always check `isValid` status, or call `startPlaying` to play the animation.
     /// - Parameter image: animated image
     public func setupPlayer(animatedImage: SDAnimatedImageProvider) {
         if isValid {
@@ -104,8 +105,6 @@ public final class ImagePlayer : ObservableObject {
             imagePlayer.playbackMode = playbackMode
 
             self.player = imagePlayer
-            
-            imagePlayer.startPlaying()
         }
     }
 }

SDWebImageSwiftUI/Classes/WebImage.swift

@@ -17,6 +17,8 @@ public struct WebImage : View {
     var placeholder: AnyView?
     var retryOnAppear: Bool = true
     var cancelOnDisappear: Bool = true
+    var pausable: Bool = true
+    var purgeable: Bool = false
 
     @ObservedObject var imageManager: ImageManager
 
@@ -26,9 +28,6 @@ public struct WebImage : View {
 
     @ObservedObject var imagePlayer: ImagePlayer
 
-    var pausable: Bool = true
-    var purgeable: Bool = false
-    
     /// Create a web image with url, placeholder, custom options and context.
     /// - Parameter url: The image url
     /// - Parameter options: The options to use when downloading the image. See `SDWebImageOptions` for the possible values.
@@ -61,35 +60,28 @@ public struct WebImage : View {
             imageManager.load()
         }
         return Group {
-            if imageManager.image != nil {
+            if let image = imageManager.image {
                 if isAnimating && !imageManager.isIncremental {
-                    if imagePlayer.currentFrame != nil {
-                        configure(image: imagePlayer.currentFrame!)
-                        .onPlatformAppear(appear: {
-                            self.imagePlayer.startPlaying()
-                        }, disappear: {
-                            if self.pausable {
-                                self.imagePlayer.pausePlaying()
-                            } else {
-                                self.imagePlayer.stopPlaying()
-                            }
-                            if self.purgeable {
-                                self.imagePlayer.clearFrameBuffer()
-                            }
-                        })
-                    } else {
-                        configure(image: imageManager.image!)
-                        .onReceive(imageManager.$image) { image in
-                            if let animatedImage = image as? SDAnimatedImageProvider {
-                                self.imagePlayer.setupPlayer(animatedImage: animatedImage)
-                            }
+                    setupPlayer()
+                    .onPlatformAppear(appear: {
+                        print("appear: \(imageManager.url)")
+                        self.imagePlayer.startPlaying()
+                    }, disappear: {
+                        print("disappear: \(imageManager.url)")
+                        if self.pausable {
+                            self.imagePlayer.pausePlaying()
+                        } else {
+                            self.imagePlayer.stopPlaying()
                         }
-                    }
+                        if self.purgeable {
+                            self.imagePlayer.clearFrameBuffer()
+                        }
+                    })
                 } else {
-                    if imagePlayer.currentFrame != nil {
-                        configure(image: imagePlayer.currentFrame!)
+                    if let currentFrame = imagePlayer.currentFrame {
+                        configure(image: currentFrame)
                     } else {
-                        configure(image: imageManager.image!)
+                        configure(image: image)
                     }
                 }
             } else {
@@ -165,6 +157,19 @@ public struct WebImage : View {
         }
     }
 
+    /// Animated Image Support
+    func setupPlayer() -> some View {
+        if let currentFrame = imagePlayer.currentFrame {
+            return configure(image: currentFrame)
+        } else {
+            if let animatedImage = imageManager.image as? SDAnimatedImageProvider {
+                self.imagePlayer.setupPlayer(animatedImage: animatedImage)
+                self.imagePlayer.startPlaying()
+            }
+            return configure(image: imageManager.image!)
+        }
+    }
+    
     /// Placeholder View Support
     func setupPlaceholder() -> some View {
         // Don't use `Group` because it will trigger `.onAppear` and `.onDisappear` when condition view removed, treat placeholder as an entire component