Trying to make rightBarButton appear after making it disappear using Swift

Question

I currently am working on an app in Swift where in my viewDidLoad() method I have purposely hidden my rightBarButton on my navigation bar like this:

self.navigationItem.rightBarButtonItem = UIBarButtonItem(barButtonSystemItem: .Done, target: self, action: #selector(TableViewController.dismiss))
self.navigationItem.setRightBarButtonItem(nil, animated: true)

However, under certain circumstances, I would like to display the rightBarButton. How would I do this? What would be the opposite of the above line of code?

Answer 1

Once you set the bar button item to nil, it is gone. Something you can do however, is store the bar button item like so:

let barButtonItem = UIBarButtonItem(barButtonSystemItem: .Done, target: self, action: #selector(TableViewController.dismiss));

and then you can make it appear/disappear like so:

self.navigationItem.rightBarButtonItem = barButtonItem
self.navigationItem.setRightBarButtonItem(nil, animated: true)

then just access the barButtonItem whenever you want it to appear/disappear.