Revert the changes to prefetch the image url from memory cache, because there are cases that the onAppear does not get called at all, which need at least update the remote URL. See #105

Author: dreampiggy

SDWebImageSwiftUI/Classes/ImageManager.swift

@@ -27,7 +27,6 @@ public final class ImageManager : ObservableObject {
     var manager: SDWebImageManager
     weak var currentOperation: SDWebImageOperation? = nil
     var isFirstLoad: Bool = true // false after first call `load()`
-    var isFirstPrefetch: Bool = true // false after first call `prefetch()`
 
     var url: URL?
     var options: SDWebImageOptions
@@ -107,28 +106,6 @@ public final class ImageManager : ObservableObject {
         }
     }
 
-    /// Prefetch the initial state of image, currently query the memory cache only
-    func prefetch() {
-        isFirstPrefetch = false
-        var options = self.options
-        if options.contains(.fromLoaderOnly) {
-            // If user indeed ignore cache, don't do prefetch
-            return
-        }
-        // Use `.fromCacheOnly` to query cache only
-        options.insert(.fromCacheOnly)
-        var context = self.context ?? [:]
-        context[.queryCacheType] = SDImageCacheType.memory.rawValue
-        // Use `.queryCacheType` to query memory cache only
-        manager.loadImage(with: url, options: options, context: context, progress: nil) { (image, data, error, cacheType, finished, imageUrl) in
-            // This will callback immediately
-            self.image = image
-            if let image = image {
-                self.successBlock?(image, cacheType)
-            }
-        }
-    }
-    
 }
 
 // Completion Handler

SDWebImageSwiftUI/Classes/WebImage.swift

@@ -60,10 +60,9 @@ public struct WebImage : View {
     }
 
     public var body: some View {
-        // this prefetch the memory cache of image, to immediately render it on screen
-        // this solve the case when `onAppear` not been called, for example, some transaction indeterminate state, SwiftUI :)
-        if imageManager.isFirstPrefetch {
-            imageManager.prefetch()
+        // This solve the case when WebImage created with new URL, but `onAppear` not been called, for example, some transaction indeterminate state, SwiftUI :)
+        if imageManager.isFirstLoad {
+            imageManager.load()
         }
         return Group {
             if imageManager.image != nil {
@@ -100,7 +99,7 @@ public struct WebImage : View {
                 setupPlaceholder()
                 .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
                 .onAppear {
-                    // load remote image when first appear
+                    // Load remote image when first appear
                     if self.imageManager.isFirstLoad {
                         self.imageManager.load()
                         return