Swift 4: NSFilenamesPboardType not available. What to use instead for registerForDraggedTypes?

Question

After migrating to Swift4 the following code raise compile error:

public final class MediaItemView: NSView {

   public override init(frame frameRect: NSRect) {
      super.init(frame: frameRect)

      // error: 'NSFilenamesPboardType' is unavailable in Swift:
      // use 'NSPasteboard.writeObjects(_:)' with file URLs
      let draggedTypes: [NSPasteboard.PasteboardType] = [NSFilenamesPboardType]
      registerForDraggedTypes(draggedTypes)
   }
}

What is a replacement for NSFilenamesPboardType in Swift4? How to register drag type of file name (in my case mp3, wav, aiff, ... files) in Swift4?

Thanks!

Answer 1

I've solved backwards compatibility with this extension:

extension NSPasteboard.PasteboardType {

    static let backwardsCompatibleFileURL: NSPasteboard.PasteboardType = {

            if #available(OSX 10.13, *) {
                return NSPasteboard.PasteboardType.fileURL
            } else {
                return NSPasteboard.PasteboardType(kUTTypeFileURL as String)
            }

    } ()

}

Which means you can use NSPasteboard.PasteboardType.backwardsCompatibleFileURL

Answer 2

i use this as the solution

    //Temp solution for this
    let NSFilenamesPboardTypeTemp = NSPasteboard.PasteboardType("NSFilenamesPboardType")

    self.zipView.registerForDraggedTypes([NSFilenamesPboardTypeTemp])

it's seem a bug from apple,them marked the api as work in 10.13 only.

Answer 3

I like the creative workarounds presented here for the deprecated variable NSFilenamesPboardType. After looking into this question, a way to move forward with an equivalent non-deprecated approach is to use readObjects(forClasses:options:). This would also be safer WRT being able to run on future macOSes. It would be implemented like the following example, tested with Swift 4.1, based on having an NSView registered in a storyboard.

override func awakeFromNib()
{
    registerForDraggedTypes([.fileURL])
}

override func draggingEnded(_ sender: NSDraggingInfo)
{
    sender
        .draggingPasteboard()
        .readObjects(forClasses: [NSURL.self],
                     options: nil)?
        .forEach
        {
            // Do something with the file paths.
            if let url = $0 as? URL { print(url.path) }
        }
}

Since the class array parameter for readObjects is of type [AnyClass] that is the reason for the use of NSURL instead of URL.

Answer 4

I'm also running into the same issue and my solution is creating a custom NSPasteboard.PasteboardType with kUTTypeURL. I'm not sure if this is the most proper way (and I suppose not), but it works at least for temporal workaround.

    let draggedType = NSPasteboard.PasteboardType(kUTTypeURL as String)
    self.tableView?.registerForDraggedTypes([draggedType])

Furthermore, the new NSPasteboard.PasteboardType has .fileNameType(forPathExtension: "foo") method. You should give a try. However somehow, it doesn't work in my case.

Answer 5

Using a combination of Mark Bridges' answer and slboat's answer, this is the solution I've come up with:

extension NSPasteboard.PasteboardType {

    /// The name of a file or directory
    static let fileName: NSPasteboard.PasteboardType = {
        return NSPasteboard.PasteboardType("NSFilenamesPboardType")
    }()
}

This works as expected in my testing.

Answer 6

Swift 5

//MARK:- Managing a Dragging Session After an Image Is Released

    override func performDragOperation(_ sender: NSDraggingInfo) -> Bool {
        let fetched = sender.draggingPasteboard.readObjects(forClasses:  [NSURL.self], options: nil)?
            .map({ (argv) -> String? in
                guard let url = argv as? URL else{
                    return nil
                }
                return url.path
            }).compactMap({$0})

        guard let result = fetched else{
            return false
        }
        // handle the result
        print(result)
        return true
    }