NSDocument Never Saves Document - swift

Question

Life was fairly easy when I first test-developed a text-based application with NSDocument. Now, I have a lot more complicated document-based desktop application with several custom models other than a string with NSTextView. My subclass of NSDocument is the following.
import Cocoa
class Document: NSDocument {
// MARK: - Variables
var image = NSImage()
var myPasteModels = [PasteModel]()
var myPanModel: PanModel?
var myWinModel: WindowModel?
// MARK: - Initialization
override init() {
super.init()
}
// MARK: - Auto saving
override class var autosavesInPlace: Bool {
return false
}
override func data(ofType typeName: String) throws -> Data {
if let viewController = windowControllers[0].contentViewController as? MainViewController {
if viewController.imageModels.count > 0 {
viewController.saveSubViewPositions()
if let window = viewController.view.window {
var pasteModels = [PasteModel]()
for i in 0..<viewController.imageModels.count {
let imageModel = viewController.imageModels[i]
...
...
}
NSKeyedArchiver.setClassName("ColorModel", for: ColorModel.self)
NSKeyedArchiver.setClassName("TextModel", for: TextModel.self)
NSKeyedArchiver.setClassName("ShapeModel", for: ShapeModel.self)
NSKeyedArchiver.setClassName("ShadeModel", for: ShadeModel.self)
NSKeyedArchiver.setClassName("LineModel", for: LineModel.self)
NSKeyedArchiver.setClassName("GradientModel", for: GradientModel.self)
NSKeyedArchiver.setClassName("ArrowModel", for: ArrowModel.self)
NSKeyedArchiver.setClassName("PasteModel", for: PasteModel.self)
NSKeyedArchiver.setClassName("PanModel", for: PanModel.self)
NSKeyedArchiver.setClassName("WindowModel", for: WindowModel.self)
let panModel = PanModel(frameWidth: viewController.panView.frame.size.width, frameHeight: viewController.panView.frame.size.height)
let winModel = WindowModel(width: window.frame.width, height: window.frame.height)
let dict = ["PasteModel": pasteModels, "PanModel": panModel, "WindowModel": winModel] as [String : Any]
do {
let modelData = try NSKeyedArchiver.archivedData(withRootObject: dict, requiringSecureCoding: false)
return modelData
} catch let error as NSError {
Swift.print("\(error)")
}
}
}
}
throw NSError(domain: NSOSStatusErrorDomain, code: unimpErr, userInfo: nil)
}
override func save(withDelegate delegate: Any?, didSave didSaveSelector: Selector?, contextInfo: UnsafeMutableRawPointer?) {
if let _ = fileURL {
Swift.print("Saved!!!")
} else {
Swift.print("Not saved yet...")
NSApp.sendAction(#selector(NSDocument.saveAs(_:)), to: nil, from: self)
}
}
override func prepareSavePanel(_ savePanel: NSSavePanel) -> Bool {
savePanel.allowedFileTypes = ["fss"]
savePanel.allowsOtherFileTypes = true
savePanel.isExtensionHidden = false
return true
}
}
The problem that I have is that the application never saves a document if I choose Save As under File (or press Command + Shift + S). If I choose Save As, the application goes beep and dismiss the command selection. It does enter the prepareSavePanel method if I set a break point there. So what can I do to go any further? Thanks.