NSOpenPanel in Swift . How to open?

@IBAction func selectAnImageFromFile(sender: AnyObject) {
    let openPanel = NSOpenPanel()
    openPanel.allowsMultipleSelection = false
    openPanel.canChooseDirectories = false
    openPanel.canCreateDirectories = false
    openPanel.canChooseFiles = true
    openPanel.beginWithCompletionHandler { (result) -> Void in
        if result == NSFileHandlingPanelOKButton {
            //Do what you will
            //If there's only one URL, surely 'openPanel.URL'
            //but otherwise a for loop works
        }
    }
}

I'm guessing you got stuck on the completion handler part? In any case, handling the URL from the open panel should be ok from there, but comment if you want me to add more. :)

Swift 4 version:

let openPanel = NSOpenPanel()
        openPanel.canChooseFiles = false
        openPanel.allowsMultipleSelection = false
        openPanel.canChooseDirectories = false
        openPanel.canCreateDirectories = false
        openPanel.title = "Select a folder"

        openPanel.beginSheetModal(for:self.view.window!) { (response) in
            if response.rawValue == NSFileHandlingPanelOKButton {
                let selectedPath = openPanel.url!.path
                // do whatever you what with the file path
            }
            openPanel.close()
        }

For Swift 4 the check of the response should be

if response == .OK { 
  ... 
}

my two cents for swift 5.0

override func showChooseFileDialog(title: String){
    let openPanel = NSOpenPanel()
    openPanel.canChooseFiles = false
    openPanel.allowsMultipleSelection = false
    openPanel.canChooseDirectories = false
    openPanel.canCreateDirectories = false
    openPanel.title = title

    openPanel.beginSheetModal(for:self.view.window!) { (response) in
        if response == .OK {
            let selectedPath = openPanel.url!.path
            // do whatever you what with the file path
        }
        openPanel.close()
    }
}