Injecting data to view controller Swift 4

PassData.swift

// Inspired by https://github.com/icanzilb/EventBlankApp

extension UIStoryboard {
    func instantiateViewController<T: UIViewController>(_ type: T.Type) -> T {
        return instantiateViewController(withIdentifier: type.classIdentifier) as! T
    }
}

extension UIViewController {
    static var classIdentifier: String { return String(describing: self) }
}

class SearchDialogViewController: UIViewController {
    var data: [Searchable]!
  
    static func createWith(storyboard: UIStoryboard = R.storyboard.entryFlow(), data: [Searchable]) -> Self {
        return storyboard.instantiateViewController(self).then { vc in
            vc.data = data
        }
    }
}

you need to set your data as private so that the only place to change the value is from within the class - e.g. no other code can randomly change it from outside 👍