Change views inside NSSplitViewController

I am trying to port my Objective-C and now improve my Swift knowledge to a Mac OS X app. Steep learning curve!

I am trying to load NSSplitViewController

with different views in the "detail view" depending on the buttons clicked on the "main view" if you do. Subsequent lessons and a search for hours brought me to zero.

I currently have:

import Cocoa

class MainSplitView: NSSplitViewController, BlissWindowDelegate {

    var masterViewController: vcMainMenu {
        let masterItem = splitViewItems[0] as! NSSplitViewItem
        return masterItem.viewController as! vcMainMenu
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        masterViewController.delegate = self

    }

    func userDidSelectFunction(function: String) {

        switch function {
        case "app":
            println("You have selected to load the appointment screen")
        case "cust":
            println("You have selected to load the customer screen")
        case "login":
            println("I think I am here and you've clicked login?")
            let detailItem = splitViewItems[1] as! NSSplitViewItem

            // Trying to load the views here ... but no idea how to

        case "admin":
            println("You've clicked admin")
        default:
            println("Nothing here ...")

        }

    }

} 

      

        
        
        
      

    

I use BlissWindowDelegate

to indicate which button was clicked. Then I try to load in splitViewItem[1]

different views from the storyboard. But no luck. Can anyone point me in the right direction please? Even for a decent link? Nothing on Google seems to be helping.

Thank.