swift splitview controller showing detail view even though it is empty - ios

Question

I'm using a split-view controller. When I start it in some devices, the master view is hidden and just the detail is shown. The detail is empty because a row hasn't been selected in master yet.
So, I need a solution that is one of the following:
1) Default the detail view to the first item in the master view.
2) Automatically show the master view, either by making it visible some how.
It is using the automatic [< Master View] bar button in the navigation bar which swift automatically adds for you.

Answer 1

As others have shared, this is unrelated to unwind segues.
If you look in the AppDelegate.swift code generated by the Master-Detail template, you'll see this UISplitViewControllerDelegate method which determines whether or not to show the detail view while collapsed:
func splitViewController(splitViewController: UISplitViewController, collapseSecondaryViewController secondaryViewController:UIViewController!, ontoPrimaryViewController primaryViewController:UIViewController!) -> Bool {
if let secondaryAsNavController = secondaryViewController as? UINavigationController {
if let topAsDetailController = secondaryAsNavController.topViewController as? DetailViewController {
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
}
The sample code is checking the detail view controller's detailItem property, to see if it has any details. If it does, the detail view is shown while collapsed, otherwise the master view is shown.
You'll have to modify this code to check the particular property you're using which holds the detail item that the master would be passing to the detail in its "showDetail" prepareForSegue.
Once you've done this, the detail view will not be shown while collapsed, if it is empty.

Answer 2

I was able to get the first row of the items into the detail view when it loads. here is the viewDidLoad of the master which is called even though its not shown to the user.
override func viewDidLoad() {
getItems() // gets the items from the web service
if let split = self.splitViewController{
let controllers = split.viewControllers
self.detailViewController = controllers[controllers.count-1].topViewController as? DetailViewController
// this line sets the "default" item
self.detailViewController?.detailItem = items.items[0]
}
}
now after the user logs in and the detail view is displayed it already is populated with the first item.

Answer 3

I had the same problem and came to the attached solution. Maybe it's for some help.
The shown class of a splitViewController is linked with the splitViewController in the storyboard.
//
// InfoMainSplitViewController.swift
//
import UIKit
class InfoMainSplitViewController: UISplitViewController, UISplitViewControllerDelegate {
// MARK: - Global variables
// variable to control if the detail view should be collapsed on launch
var forceDetailToColapse : Bool = false
// MARK: - Lifetime management
override func viewDidLoad() {
super.viewDidLoad()
// set the delegate to get access to the delegate methods
self.delegate = self
// if this is an iPad, show both scenes (selection and detail) side by side
if (UIDevice.current.userInterfaceIdiom == UIUserInterfaceIdiom.pad) {
// we have an iPad, so set the mode
self.preferredDisplayMode = UISplitViewControllerDisplayMode.allVisible
// we do not want to collapse the detail view on launch
forceDetailToColapse = false
} else {
// we have an iPhone, set the mode
self.preferredDisplayMode = UISplitViewControllerDisplayMode.automatic
// make sure we collapse the detail view on launch
forceDetailToColapse = true
}
}
// MARK: - Delegate methods
// used to collapse the detail view
// BTW: this method will not be called if preferredDisplayMode == UISplitViewControllerDisplayMode.allVisible
func splitViewController(_ splitViewController: UISplitViewController, collapseSecondary secondaryViewController: UIViewController, onto primaryViewController: UIViewController) -> Bool {
// true: detail view will collapse, false: detail View will not collapse
return forceDetailToColapse
}
}