Hiding the master view controller with UISplitViewController in iOS8

Use preferredDisplayMode. In didSelectRowAtIndexPath or prepareForSegue:

self.splitViewController?.preferredDisplayMode = .PrimaryHidden
self.splitViewController?.preferredDisplayMode = .Automatic

Unfortunately the master view abruptly disappears instead of sliding away, despite the documentation stating:

If changing the value of this property leads to an actual change in the current display mode, the split view controller animates the resulting change.

Hopefully there is a better way to do this that actually animates the change.

The code below hides the master view with animation

UIView.animateWithDuration(0.5) { () -> Void in
            self.splitViewController?.preferredDisplayMode = .PrimaryHidden
        }

Extend the UISplitViewController as follows:

extension UISplitViewController {
    func toggleMasterView() {
        let barButtonItem = self.displayModeButtonItem()
        UIApplication.sharedApplication().sendAction(barButtonItem.action, to: barButtonItem.target, from: nil, forEvent: nil)
    }
}

In didSelectRowAtIndexPath or prepareForSegue, do the following:

self.splitViewController?.toggleMasterView()

This will smoothly slide the master view out of the way.

I got the idea of using the displayModeButtonItem() from this post and I am simulating a tap on it per this post.

I am not really happy with this solution, since it seems like a hack. But it works well and there seems to be no alternative yet.