Only use the appGroupTemporaryDirectory to access a file from the share extension. (#4002)

… and switch back to the plain `URL.temporaryDirectory` for everything else.

* Fix documentation

Co-authored-by: Stefan Ceriu <stefan.ceriu@gmail.com>

ElementX/Sources/Other/Extensions/FileManager.swift

@@ -37,8 +37,9 @@ extension FileManager {
     }
 
     @discardableResult
-    func writeDataToTemporaryDirectory(data: Data, fileName: String) throws -> URL {
-        let newURL = URL.appGroupTemporaryDirectory.appendingPathComponent(fileName)
+    func writeDataToTemporaryDirectory(data: Data, fileName: String, withinAppGroupContainer: Bool = false) throws -> URL {
+        let baseURL: URL = withinAppGroupContainer ? .appGroupTemporaryDirectory : .temporaryDirectory
+        let newURL = baseURL.appendingPathComponent(fileName)
         
         try data.write(to: newURL)
         

ElementX/Sources/Other/Extensions/NSItemProvider.swift

@@ -28,20 +28,23 @@ extension NSItemProvider {
         try? await loadItem(forTypeIdentifier: UTType.text.identifier) as? String
     }
     
-    func storeData() async -> URL? {
+    /// Stores the item's data from the provider within the temporary directory, returning the URL on success.
+    /// - Parameter withinAppGroupContainer: Whether the data needs to be shared between bundles.
+    /// If passing `true` you will need to manually clean up the file once you have the data in the receiving bundle.
+    func storeData(withinAppGroupContainer: Bool = false) async -> URL? {
         guard let contentType = preferredContentType else {
             MXLog.error("Invalid NSItemProvider: \(self)")
             return nil
         }
         
         if contentType.type.identifier == UTType.image.identifier {
-            return await generateURLForUIImage(contentType)
+            return await generateURLForUIImage(contentType, withinAppGroupContainer: withinAppGroupContainer)
         } else {
-            return await generateURLForGenericData(contentType)
+            return await generateURLForGenericData(contentType, withinAppGroupContainer: withinAppGroupContainer)
         }
     }
     
-    private func generateURLForUIImage(_ contentType: PreferredContentType) async -> URL? {
+    private func generateURLForUIImage(_ contentType: PreferredContentType, withinAppGroupContainer: Bool) async -> URL? {
         guard let uiImage = try? await loadItem(forTypeIdentifier: contentType.type.identifier) as? UIImage else {
             MXLog.error("Failed casting UIImage, invalid NSItemProvider: \(self)")
             return nil
@@ -52,22 +55,25 @@ extension NSItemProvider {
             return nil
         }
         
+        let filename = if let suggestedName = suggestedName as NSString?,
+                          // Suggestions are nice but their extension is `jpeg`
+                          let filename = (suggestedName.deletingPathExtension as NSString).appendingPathExtension(contentType.fileExtension) {
+            filename
+        } else {
+            "\(UUID().uuidString).\(contentType.fileExtension)"
+        }
+        
         do {
-            if let suggestedName = suggestedName as? NSString,
-               // Suggestions are nice but their extension is `jpeg`
-               let filename = (suggestedName.deletingPathExtension as NSString).appendingPathExtension(contentType.fileExtension) {
-                return try FileManager.default.writeDataToTemporaryDirectory(data: pngData, fileName: filename)
-            } else {
-                let filename = "\(UUID().uuidString).\(contentType.fileExtension)"
-                return try FileManager.default.writeDataToTemporaryDirectory(data: pngData, fileName: filename)
-            }
+            return try FileManager.default.writeDataToTemporaryDirectory(data: pngData,
+                                                                         fileName: filename,
+                                                                         withinAppGroupContainer: withinAppGroupContainer)
         } catch {
             MXLog.error("Failed storing NSItemProvider data \(self) with error: \(error)")
             return nil
         }
     }
     
-    private func generateURLForGenericData(_ contentType: PreferredContentType) async -> URL? {
+    private func generateURLForGenericData(_ contentType: PreferredContentType, withinAppGroupContainer: Bool) async -> URL? {
         let providerDescription = description
         let shareData: Data? = await withCheckedContinuation { continuation in
             _ = loadDataRepresentation(for: contentType.type) { data, error in
@@ -92,15 +98,19 @@ extension NSItemProvider {
             return nil
         }
         
+        let filename = if let suggestedName = suggestedName as NSString?,
+                          suggestedName.hasPathExtension {
+            suggestedName as String
+        } else if let suggestedName {
+            "\(suggestedName).\(contentType.fileExtension)"
+        } else {
+            "\(UUID().uuidString).\(contentType.fileExtension)"
+        }
+        
         do {
-            if let filename = suggestedName {
-                let hasExtension = !(filename as NSString).pathExtension.isEmpty
-                let filename = hasExtension ? filename : "\(filename).\(contentType.fileExtension)"
-                return try FileManager.default.writeDataToTemporaryDirectory(data: shareData, fileName: filename)
-            } else {
-                let filename = "\(UUID().uuidString).\(contentType.fileExtension)"
-                return try FileManager.default.writeDataToTemporaryDirectory(data: shareData, fileName: filename)
-            }
+            return try FileManager.default.writeDataToTemporaryDirectory(data: shareData,
+                                                                         fileName: filename,
+                                                                         withinAppGroupContainer: withinAppGroupContainer)
         } catch {
             MXLog.error("Failed storing NSItemProvider data \(self) with error: \(error)")
             return nil
@@ -164,3 +174,7 @@ extension NSItemProvider {
         return mimeType.hasPrefix("image/") || mimeType.hasPrefix("video/") || mimeType.hasPrefix("application/")
     }
 }
+
+private extension NSString {
+    var hasPathExtension: Bool { !pathExtension.isEmpty }
+}

ElementX/Sources/Other/Extensions/URL.swift

@@ -75,7 +75,10 @@ extension URL: @retroactive ExpressibleByStringLiteral {
         return url
     }
     
-    /// The app group temporary directory
+    /// The app group temporary directory (useful for transferring files between different bundles).
+    ///
+    /// **Note:** This `tmp` directory doesn't appear to behave as expected as it isn't being tidied up by the system.
+    /// Make sure to manually tidy up any files you place in here once you've transferred them from one bundle to another.
     static var appGroupTemporaryDirectory: URL {
         let url = appGroupContainerDirectory
             .appendingPathComponent("tmp", isDirectory: true)