Fix saving to an icloud folder.

OpenGpxTracker/GPXFileManager.swift

@@ -74,38 +74,44 @@ class GPXFileManager: NSObject {
     /// - Parameters:
     ///     - fileURL: destination URL, basically it is file path.
     ///     - gpxContents: String with the contents to be saved. The XML contents of the GPX file
+    /// - Returns: `nil` on success, or the `Error` that caused the write to fail.
     ///
-    class func saveToURL(_ fileURL: URL, gpxContents: String) {
+    @discardableResult
+    class func saveToURL(_ fileURL: URL, gpxContents: String) -> Error? {
         // Save file
         print("Saving file at path: \(fileURL)")
+        // When the GPX files folder is a user-picked location (f.i. an iCloud
+        // Drive folder), the folder URL is security-scoped and must be unlocked
+        // before we can write into it. This mirrors what `fileList` does for reads.
+        let folderURL = GPXFileManager.GPXFilesFolderURL
+        let secured = folderURL.startAccessingSecurityScopedResource()
+        defer {
+            if secured {
+                folderURL.stopAccessingSecurityScopedResource()
+            }
+        }
         // write gpx to file
-        var writeError: NSError?
-        let saved: Bool
         do {
             try gpxContents.write(toFile: fileURL.path, atomically: true, encoding: String.Encoding.utf8)
-            saved = true
-        } catch let error as NSError {
-            writeError = error
-            saved = false
-        }
-        if !saved {
-            if let error = writeError {
-                print("[ERROR] GPXFileManager:save: \(error.localizedDescription)")
-            }
+            return nil
+        } catch {
+            print("[ERROR] GPXFileManager:save: \(error.localizedDescription)")
+            return error
         }
-
     }
     ///
     /// Saves in the default folder the filename with the gpxContents
     ///
     /// - Parameters:
     ///     - filename: gpx filename with .gpx extension (f.i: `hola.gpx`) or without extension (f.i: `hola`)
     ///     - gpxContents: String with the contents to be saved. The XML contents of the GPX file
+    /// - Returns: `nil` on success, or the `Error` that caused the write to fail.
     ///
-    class func save(_ filename: String, gpxContents: String) {
+    @discardableResult
+    class func save(_ filename: String, gpxContents: String) -> Error? {
         // Check if name exists
         let fileURL: URL = self.URLForFilename(filename)
-        GPXFileManager.saveToURL(fileURL, gpxContents: gpxContents)
+        return GPXFileManager.saveToURL(fileURL, gpxContents: gpxContents)
     }
 
     ///
@@ -123,12 +129,21 @@ class GPXFileManager: NSObject {
             return
         }
 
+        // The destination folder may be a security-scoped user-picked location
+        // (f.i. an iCloud Drive folder), so unlock it before moving into it.
+        let folderURL = GPXFilesFolderURL
+        let secured = folderURL.startAccessingSecurityScopedResource()
+        defer {
+            if secured {
+                folderURL.stopAccessingSecurityScopedResource()
+            }
+        }
         // attempt to move file
         do {
-            let url = GPXFilesFolderURL.path + "/" + fileName
+            let url = folderURL.path + "/" + fileName
             try FileManager().moveItem(atPath: fileURL.path, toPath: url)
         }
-            
+
         // file move failure
         catch {
             print("GPXFileManager:: save failed, error: \(error)")
@@ -138,6 +153,15 @@ class GPXFileManager: NSObject {
     /// Removes a file on the specified URL
     class func removeFileFromURL(_ fileURL: URL) {
         print("Removing file at path: \(fileURL)")
+        // The file may live in a security-scoped user-picked folder (f.i. an
+        // iCloud Drive folder), so unlock it before attempting to delete.
+        let folderURL = GPXFileManager.GPXFilesFolderURL
+        let secured = folderURL.startAccessingSecurityScopedResource()
+        defer {
+            if secured {
+                folderURL.stopAccessingSecurityScopedResource()
+            }
+        }
         let defaultManager = FileManager.default
         var error: NSError?
         let deleted: Bool

OpenGpxTracker/ViewController.swift

@@ -1198,7 +1198,12 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
             print("Save File \(String(describing: filename))")
             // Export to a file
             let gpxString = self.map.exportToGPXString()
-            GPXFileManager.save(filename!, gpxContents: gpxString)
+            if let error = GPXFileManager.save(filename!, gpxContents: gpxString) {
+                // The write failed (f.i. a stale/denied security-scoped iCloud
+                // folder). Tell the user instead of silently pretending it saved.
+                self.displaySaveErrorAlert(error)
+                return
+            }
             self.lastGpxFilename = filename!
             self.map.coreDataHelper.coreDataDeleteAll(of: CDRoot.self)
             self.map.coreDataHelper.clearAllExceptWaypoints()
@@ -1213,9 +1218,26 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
         alertController.addAction(cancelAction)
 
         present(alertController, animated: true)
-        
+
     }
-
+
+    ///
+    /// Displays an alert informing the user that saving the GPX file failed.
+    ///
+    /// This is most commonly hit when the GPX files folder is a user-picked
+    /// location (f.i. an iCloud Drive folder) whose security-scoped access could
+    /// not be acquired — e.g. the bookmark went stale or the folder was moved.
+    ///
+    /// - Parameter error: The underlying error returned by the file write.
+    ///
+    func displaySaveErrorAlert(_ error: Error) {
+        let alertController = UIAlertController(title: NSLocalizedString("SAVE_ERROR_TITLE", comment: "no comment"),
+                                                message: error.localizedDescription,
+                                                preferredStyle: .alert)
+        alertController.addAction(UIAlertAction(title: NSLocalizedString("DONE", comment: "no comment"), style: .default))
+        present(alertController, animated: true)
+    }
+
     ///
     /// There was a memory warning. Right now, it does nothing but to log a line.
     ///

OpenGpxTracker/de.lproj/Localizable.strings

@@ -130,3 +130,4 @@
 "DEFAULT_NAME_SAMPLE_OUTPUT_TITLE" = "Sample: ";
 "DEFAULT_NAME_USE_UTC" = "Use UTC Time?";
 "DEFAULT_NAME_ENGLISH_LOCALE" = "Force English language based date formatting?";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/en.lproj/Localizable.strings

@@ -162,3 +162,4 @@
 "LOCATION" = "Location";
 "LOCATION_TIME" = "Location's Time";
 
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/es.lproj/Localizable.strings

@@ -161,3 +161,4 @@
 "GMT_FULL" = "GMT completo";
 "LOCATION" = "Ubicación";
 "LOCATION_TIME" = "Hora en la ubicación";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/fi-FI.lproj/Localizable.strings

@@ -117,3 +117,4 @@ Created by Phiilman on 28.03.20.
 
 "CONTINUE_SESSION" = "Jatka tapahtumaa";
 "SAVE_START_NEW" = "Tallenna ja aloita uusi tapahtuma";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/fr.lproj/Localizable.strings

@@ -163,3 +163,4 @@
 "LOCATION" = "Localisation";
 "LOCATION_TIME" = "Heure locale";
 
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/it.lproj/Localizable.strings

@@ -130,3 +130,4 @@
 "DEFAULT_NAME_SAMPLE_OUTPUT_TITLE" = "Esempio: ";
 "DEFAULT_NAME_USE_UTC" = "Usare fuso orario UTC?";
 "DEFAULT_NAME_ENGLISH_LOCALE" = "Forza la formattazione della data basata sulla lingua inglese?";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/ja.lproj/Localizable.strings

@@ -161,3 +161,4 @@
 "GMT_FULL" = "GMT完全";
 "LOCATION" = "地域";
 "LOCATION_TIME" = "地域の時刻";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/nl.lproj/Localizable.strings

@@ -161,3 +161,4 @@
 "GMT_FULL" = "GMT volledig";
 "LOCATION" = "Locatie";
 "LOCATION_TIME" = "Locatietijd";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/pt-BR.lproj/Localizable.strings

@@ -164,3 +164,4 @@
 "LOCATION" = "Localização";
 "LOCATION_TIME" = "Hora da localização";
 
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/ru.lproj/Localizable.strings

@@ -162,3 +162,4 @@
 "LOCATION" = "Местоположение";
 "LOCATION_TIME" = "Время местоположения";
 
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/uk.lproj/Localizable.strings

@@ -133,3 +133,4 @@
 "DEFAULT_NAME_SAMPLE_OUTPUT_TITLE" = "Sample: ";
 "DEFAULT_NAME_USE_UTC" = "Use UTC Time?";
 "DEFAULT_NAME_ENGLISH_LOCALE" = "Force English language based date formatting?";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";

OpenGpxTracker/zh-Hans.lproj/Localizable.strings

@@ -164,3 +164,4 @@
 "GMT_FULL" = "GMT 整体";
 "LOCATION" = "地点";
 "LOCATION_TIME" = "地点时区";
+"SAVE_ERROR_TITLE" = "Could not save GPX file";