AttachmentsFeatureElementView - Block empty file upload/download/preview

Sources/ArcGISToolkit/Common/AttachmentList.swift

@@ -33,7 +33,7 @@ struct AttachmentRow: View  {
     @ObservedObject var attachmentModel: AttachmentModel
 
     /// The url of the the attachment, used to display the attachment via `QuickLook`.
-    @State var url: URL?
+    @State private var url: URL?
 
     var body: some View {
         HStack {
@@ -67,9 +67,14 @@ struct AttachmentRow: View  {
 struct AttachmentLoadButton: View  {
     @ObservedObject var attachmentModel: AttachmentModel
 
+    /// A Boolean value indicating whether the download alert is presented.
+    @State private var downloadAlertIsPresented = false
+
     var body: some View {
         Button {
-            if attachmentModel.loadStatus == .notLoaded {
+            if attachmentModel.attachment.measuredSize.value.isZero {
+                downloadAlertIsPresented = true
+            } else if attachmentModel.loadStatus == .notLoaded {
                 attachmentModel.load()
             }
         } label: {
@@ -95,5 +100,8 @@ struct AttachmentLoadButton: View  {
             .frame(width: 24, height: 24)
             .padding(.leading)
         }
+        .alert(isPresented: $downloadAlertIsPresented) {
+            Alert(title: Text.emptyAttachmentDownloadErrorMessage)
+        }
     }
 }

Sources/ArcGISToolkit/Common/AttachmentModel.swift

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 import ArcGIS
-import Combine
+import OSLog
 import QuickLook
 import SwiftUI
 
@@ -86,7 +86,11 @@ import SwiftUI
     func load() {
         Task {
             loadStatus = .loading
-            try await attachment.load()
+            do {
+                try await attachment.load()
+            } catch {
+                Logger.attachmentsFeatureElementView.error("Attachment loading failed \(error.localizedDescription)")
+            }
             sync()
             if loadStatus == .failed || attachment.fileURL == nil {
                 systemImageName = "exclamationmark.circle.fill"

Sources/ArcGISToolkit/Common/AttachmentPreview.swift

@@ -154,6 +154,9 @@ struct AttachmentPreview: View {
         /// The model representing the attachment to display.
         @ObservedObject var attachmentModel: AttachmentModel
 
+        /// A Boolean value indicating whether the download alert is presented.
+        @State private var downloadAlertIsPresented = false
+
         /// The url of the the attachment, used to display the attachment via `QuickLook`.
         @State private var url: URL?
 
@@ -205,12 +208,17 @@ struct AttachmentPreview: View {
                 if attachmentModel.attachment.loadStatus == .loaded {
                     // Set the url to trigger `.quickLookPreview`.
                     url = attachmentModel.attachment.fileURL
+                } else if attachmentModel.attachment.measuredSize.value.isZero {
+                    downloadAlertIsPresented = true
                 } else if attachmentModel.attachment.loadStatus == .notLoaded {
                     // Load the attachment model with the given size.
                     attachmentModel.load()
                 }
             }
             .quickLookPreview($url)
+            .alert(isPresented: $downloadAlertIsPresented) {
+                Alert(title: Text.emptyAttachmentDownloadErrorMessage)
+            }
         }
     }
 }

Sources/ArcGISToolkit/Components/FeatureFormView/AttachmentHelpers/AttachmentImportError.swift

@@ -15,6 +15,7 @@
 /// The possible errors when importing an attachment.
 enum AttachmentImportError: Error, Equatable {
     case dataInaccessible
+    case emptyFilesNotSupported
     case sizeLimitExceeded
     case system(String)
 }

Sources/ArcGISToolkit/Components/FeatureFormView/AttachmentHelpers/AttachmentImportMenu.swift

@@ -160,6 +160,10 @@ struct AttachmentImportMenu: View {
                 importState = .errored(.sizeLimitExceeded)
                 return
             }
+            guard attachmentSize.value > .zero else {
+                importState = .errored(.emptyFilesNotSupported)
+                return
+            }
 
             defer { importState = .none }
             let fileName: String
@@ -260,6 +264,15 @@ private extension AttachmentImportMenu {
         )
     }
 
+    /// An error message indicating the selected attachment is an empty file and not supported.
+    var emptyFilesNotSupportedAlertMessage: String {
+        .init(
+            localized: "Empty files are not supported.",
+            bundle: .toolkitModule,
+            comment: "An error message indicating the selected attachment is an empty file and not supported."
+        )
+    }
+
     /// A label for a button to choose an file from the user's files.
     var filesButtonLabel: String {
         .init(
@@ -285,6 +298,8 @@ private extension AttachmentImportMenu {
     var importFailureAlertMessage: String {
         guard case .errored(let attachmentImportError) = importState else { return "" }
         return switch attachmentImportError {
+        case .emptyFilesNotSupported:
+            emptyFilesNotSupportedAlertMessage
         case .sizeLimitExceeded:
             sizeLimitExceededImportFailureAlertMessage
         default:

Sources/ArcGISToolkit/Extensions/OS/Logger.swift

@@ -0,0 +1,22 @@
+// Copyright 2024 Esri
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import OSLog
+
+extension Logger {
+    /// A logger for the common `AttachmentsFeatureElementView` view.
+    static let attachmentsFeatureElementView: Logger = {
+        Logger(subsystem: Bundle.toolkitIdentifier, category: "AttachmentsFeatureElementView")
+    }()
+}

Sources/ArcGISToolkit/Extensions/SwiftUI/Text.swift

@@ -24,6 +24,15 @@ extension Text {
         )
     }
 
+    /// An error message explaining attachments with empty files (0 bytes) cannot be downloaded.
+    static var emptyAttachmentDownloadErrorMessage: Self {
+        .init(
+            "Empty attachments cannot be downloaded.",
+            bundle: .toolkitModule,
+            comment: "An error message explaining attachments with empty files (0 bytes) cannot be downloaded."
+        )
+    }
+
     /// Localized text for the word "Required".
     static var required: Self {
         Text(

Sources/ArcGISToolkit/Resources/en.lproj/Localizable.strings

@@ -117,6 +117,12 @@ for a utility network trace. */
 AR experience. */
 "elevation" = "elevation";
 
+/* An error message explaining attachments with empty files (0 bytes) cannot be downloaded. */
+"Empty attachments cannot be downloaded." = "Empty attachments cannot be downloaded.";
+
+/* An error message indicating the selected attachment is an empty file and not supported. */
+"Empty files are not supported." = "Empty files are not supported.";
+
 /* Text indicating a field's value must be within the
 allowed length range. The first and second parameter
 hold the minimum and maximum length respectively. */