Image caching fixes

Nextcloud Cookbook iOS Client/Data/DataModels.swift

@@ -63,6 +63,7 @@ struct RecipeDetail: Codable {
 }
 
 struct RecipeImage {
+    var imageExists: Bool = true
     var thumb: UIImage?
     var full: UIImage?
 }

Nextcloud Cookbook iOS Client/Data/DataStore.swift

@@ -16,10 +16,18 @@ class DataStore {
             appropriateFor: nil,
             create: false
         )
-
         .appendingPathComponent(appending)
     }
     
+    private static func fileURL() throws -> URL {
+        try FileManager.default.url(
+            for: .documentDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: false
+        )
+    }
+    
     func load<D: Decodable>(fromPath path: String) async throws -> D? {
         let task = Task<D?, Error> {
             let fileURL = try Self.fileURL(appending: path)
@@ -45,12 +53,24 @@ class DataStore {
         }
     }
     
-    func clearAll() {
+    func clearAll() -> Bool {
+        print("Attempting to delete all data ...")
+        let fm = FileManager.default
+        guard let folderPath = fm.urls(for: .documentDirectory, in: .userDomainMask).first?.path() else { return false }
+        print("Folder path: ", folderPath)
         do {
-            try FileManager.default.removeItem(at: Self.fileURL(appending: ""))
+            let filePaths = try fm.contentsOfDirectory(atPath: folderPath)
+            for filePath in filePaths {
+                print("File path: ", filePath)
+                try fm.removeItem(atPath: folderPath + filePath)
+            }
         } catch {
-            print("Could not delete file, probably read-only filesystem")
+            print("Could not delete documents folder contents: \(error)")
+            return false
         }
+        print("Done.")
+        return true
+        
     }
     
 }

Nextcloud Cookbook iOS Client/ViewModels/MainViewModel.swift

@@ -77,22 +77,36 @@ import UIKit
     ///     - needsUpdate: Determines wether the image should be loaded directly from the server, or if it should be loaded from cache/store first.
     /// - Returns: The image if found locally or on the server, otherwise nil.
     func loadImage(recipeId: Int, full: Bool, needsUpdate: Bool = false) async -> UIImage? {
-        print("loadImage(recipeId: \(recipeId), full: \(full), needsUpdate: \(needsUpdate)")
+        print("loadImage(recipeId: \(recipeId), full: \(full), needsUpdate: \(needsUpdate))")
         // If the image needs an update, request it from the server and overwrite the stored image
         if needsUpdate {
             if let data = await imageDataFromServer(recipeId: recipeId, full: full) {
-                guard let image = UIImage(data: data) else { return nil }
+                guard let image = UIImage(data: data) else {
+                    imageCache[recipeId] = RecipeImage(imageExists: false)
+                    return nil
+                }
                 await dataStore.save(data: data.base64EncodedString(), toPath: localImagePath(recipeId, full))
                 imageToCache(image: image, recipeId: recipeId, full: full)
                 return image
+            } else {
+                imageCache[recipeId] = RecipeImage(imageExists: false)
+                return nil
             }
         }
+        
+        // Check imageExists flag to detect if we attempted to load a non-existing image before.
+        // This allows us to avoid sending requests to the server if we already know the recipe has no image.
+        if imageCache[recipeId] != nil {
+            guard imageCache[recipeId]!.imageExists else { return nil }
+        }
+        
         // Try to load image from cache
         print("Attempting to load image from cache ...")
-        if imageCache[recipeId] != nil {
+        if let image = imageFromCache(recipeId: recipeId, full: full) {
             print("Image found in cache.")
-            return imageFromCache(recipeId: recipeId, full: full)
+            return image
         }
+        
         // Try to load from store
         print("Attempting to load image from local storage ...")
         if let image = await imageFromStore(recipeId: recipeId, full: full) {
@@ -100,18 +114,32 @@ import UIKit
             imageToCache(image: image, recipeId: recipeId, full: full)
             return image
         }
+        
         // Try to load from the server. Store if successfull.
         print("Attempting to load image from server ...")
         if let data = await imageDataFromServer(recipeId: recipeId, full: full) {
             print("Image data received.")
-            imageCache[recipeId] = RecipeImage() // Create empty RecipeImage for each recipe even if no image found, so that further server requests are only sent if explicitly requested.
+            // Create empty RecipeImage for each recipe even if no image found, so that further server requests are only sent if explicitly requested.
-            guard let image = UIImage(data: data) else { return nil }
+            guard let image = UIImage(data: data) else {
+                imageCache[recipeId] = RecipeImage(imageExists: false)
+                return nil
+            }
             await dataStore.save(data: data.base64EncodedString(), toPath: localImagePath(recipeId, full))
             imageToCache(image: image, recipeId: recipeId, full: full)
             return image
         }
+        imageCache[recipeId] = RecipeImage(imageExists: false)
         return nil
     }
+    
+    func deleteAllData() {
+        if dataStore.clearAll() {
+            self.categories = []
+            self.recipes = [:]
+            self.imageCache = [:]
+            self.recipeDetails = [:]
+        }
+    }
 }
 
 
@@ -140,11 +168,13 @@ extension MainViewModel {
     
     private func imageToCache(image: UIImage, recipeId: Int, full: Bool) {
         if imageCache[recipeId] == nil {
-            imageCache[recipeId] = RecipeImage()
+            imageCache[recipeId] = RecipeImage(imageExists: true)
         }
         if full {
+            imageCache[recipeId]!.imageExists = true
             imageCache[recipeId]!.full = image
         } else {
+            imageCache[recipeId]!.imageExists = true
             imageCache[recipeId]!.thumb = image
         }
     }

Nextcloud Cookbook iOS Client/Views/MainView.swift

@@ -30,7 +30,7 @@ struct MainView: View {
             }
             .navigationTitle("CookBook")
             .toolbar {
-                NavigationLink( destination: SettingsView(userSettings: userSettings)) {
+                NavigationLink( destination: SettingsView(userSettings: userSettings, viewModel: viewModel)) {
                     Image(systemName: "gear")
                 }
             }

Nextcloud Cookbook iOS Client/Views/SettingsView.swift

@@ -10,6 +10,7 @@ import SwiftUI
 
 struct SettingsView: View {
     @ObservedObject var userSettings: UserSettings
+    @ObservedObject var viewModel: MainViewModel
     
     var body: some View {
         List {
@@ -33,7 +34,7 @@ struct SettingsView: View {
             {
                 Button("Clear Cache") {
                     print("Clear cache.")
-                    
+                    viewModel.deleteAllData()
                 }
                 .buttonStyle(.borderedProminent)
                 .accentColor(.red)