Swift 4 Split View Controller Detail Replaces Master - ios

Question

I just started building an app and right now I am adding 2 Split View Controllers, in my Main.storyboard it looks like this image
I added the following code to my Master:
import UIKit
class ContactsMaster: UITableViewController {
var ContactsDetailController: ContactsDetail? = nil
var objects = [Any]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
navigationItem.leftBarButtonItem = editButtonItem
let addButton = UIBarButtonItem(barButtonSystemItem: .add, target: self, action: #selector(insertNewObject(_:)))
navigationItem.rightBarButtonItem = addButton
if let split = splitViewController {
let controllers = split.viewControllers
ContactsDetailController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? ContactsDetail
}
}
override func viewWillAppear(_ animated: Bool) {
clearsSelectionOnViewWillAppear = splitViewController!.isCollapsed
super.viewWillAppear(animated)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#objc
func insertNewObject(_ sender: Any) {
objects.insert(NSDate(), at: 0)
let indexPath = IndexPath(row: 0, section: 0)
tableView.insertRows(at: [indexPath], with: .automatic)
}
// MARK: - Segues
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showContactDetail" {
if let indexPath = tableView.indexPathForSelectedRow {
let object = objects[indexPath.row] as! NSDate
let controller = (segue.destination as! UINavigationController).topViewController as! ContactsDetail
controller.detailItem = object
controller.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
controller.navigationItem.leftItemsSupplementBackButton = true
}
}
}
// MARK: - Table View
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return objects.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
let object = objects[indexPath.row] as! NSDate
cell.textLabel!.text = object.description
return cell
}
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
objects.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)
} else if editingStyle == .insert {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view.
}
}
}
And here is my Detail:
import UIKit
class ContactsDetail: UIViewController {
#IBOutlet weak var detailDescriptionLabel: UILabel!
func configureView() {
// Update the user interface for the detail item.
if let detail = detailItem {
if let label = detailDescriptionLabel {
label.text = detail.description
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
configureView()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
var detailItem: NSDate? {
didSet {
// Update the view.
configureView()
}
}
}
My problem is when I run my app and goto the Split View Controller and select an item in the Master, it does not goto the Detail, but instead replaces the master.
I have a sample app that is just the Split View Controller and I noticed in the App Delegate file of the sample app there is this code in the application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool method:
let splitViewController = window!.rootViewController as! UISplitViewController
let navigationController = splitViewController.viewControllers[splitViewController.viewControllers.count-1] as! UINavigationController
navigationController.topViewController!.navigationItem.leftBarButtonItem = splitViewController.displayModeButtonItem
splitViewController.delegate = self
And there is also this method:
func splitViewController(_ splitViewController: UISplitViewController, collapseSecondary secondaryViewController:UIViewController, onto primaryViewController:UIViewController) -> Bool {
guard let secondaryAsNavController = secondaryViewController as? UINavigationController else { return false }
guard let topAsDetailController = secondaryAsNavController.topViewController as? DetailViewController else { return false }
if topAsDetailController.detailItem == nil {
// Return true to indicate that we have handled the collapse by doing nothing; the secondary controller will be discarded.
return true
}
return false
}
My problem with this code is that my Split View Controller is not the inital controller and my problem with the splitViewController method, I have 2 split view controllers, I can only specificity 1 of them. How do I get this split view controller without making it the inital controller?

Answer 1

your master class must implement UISplitViewControllerDelegate.
so first thing you need to do :
class ContactsMaster: UITableViewController,UISplitViewControllerDelegate {
and override this function in your master:
func splitViewController(splitViewController: UISplitViewController, collapseSecondaryViewController secondaryViewController: UIViewController, ontoPrimaryViewController primaryViewController: UIViewController) -> Bool {
return true
}
then in viewDidLoad(master class) add following cods:
self.splitViewController!.delegate = self;
self.splitViewController!.preferredDisplayMode = UISplitViewControllerDisplayMode.AllVisible
self.extendedLayoutIncludesOpaqueBars = true
I think you skip many steps for configuring splitviewcontroller, if you want to understand all the way you can read one of many tutorials written for it, like:
http://nshipster.com/uisplitviewcontroller/

Answer 2

Did you by chance forget to set the ContactsDetail class for your Detail VC in your Storyboard?