file previews work again!

enzevalos_iphone/SwiftUI/Compose/AddAttachmentsModel.swift

@@ -22,6 +22,21 @@ struct Attachment: DisplayAttachment, Equatable {
         myID = UUID()
     }
     
+    /// download calling attachment into the documents diectory
+    func download(){
+        func getDocumentsDirectory() -> URL {
+            let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
+            return paths[0]
+        }
+        let filename = getDocumentsDirectory().appendingPathComponent(self.myName)
+        
+        do {
+            try self.myData.write(to: filename)
+        } catch let error as NSError {
+            print("Error: \(error)")
+        }
+    }
+    
     /// a func that returns the size of the calling attachment file as a string
     func countData() -> String {
         // size in byte

enzevalos_iphone/SwiftUI/Compose/AddAttachmentsView.swift

@@ -113,6 +113,10 @@ struct AddAttachmentsView: View {
                 //  create Attachment and add in to the attachments list
                 let newAttachment = Attachment(fileName: fileName, fileData: fileData)
                 model.attachments.append(newAttachment)
+                // download the file into the documents directory
+                // this is necessary, because the QuickLookView later uses that data
+                // to create a preview
+                newAttachment.download()
             } catch {
                 //  Error while loading file
                 print("Error while importing file.")