Swift 3 - IBOutlet nil after copy UIView - ios

Question

i have a question about a more or less special case. I have to copy a UIView which is loaded from nib. This is the initaliziation of the source variable:
let view = Bundle.loadView(fromNib: "MyView", withType: MyView.self)
The view has two labels as outlets properties like so:
class MyView: UIView {
#IBOutlet weak var label: UILabel!
#IBOutlet weak var subLabel: UILabel!
}
In my case I have to copy this view. So I found this solution which should work fine:
import UIKit
extension UIView
{
func copyView<T: UIView>() -> T {
return NSKeyedUnarchiver.unarchiveObject(with: NSKeyedArchiver.archivedData(withRootObject: self)) as! T
}
}
Unfortunately when I call this line:
let copyView = view.copyView()
The label and subLabel properties are nil. In view they are set. The FilesOwner in the MyView.xib is set to the MyView class
Could the copy function work in my case? Has someone an advice how to proceed here?

Answer 1

Get UIView using below method
let view = MyView(nibName: "MyView", bundle: nil)
Hope it help.

Answer 2

To be honest there is still something strange about your use case although I don´t know your whole code but I don´t see the point in using the NSKeyedArchiver for what you want to achieve. Of course it is possible to instantiate a new UIView instance and still take advantage of polymorphism. Here´s how:
Imagine you have the following extension to instantiate a generic view controller:
import UIKit
extension UIView {
class func fromNib(owner: AnyObject? = nil) -> Self {
return UIView.fromNib(owner: owner)
}
class func fromNib<T : UIView>(owner: AnyObject? = nil) -> T {
return UIView.fromNib(withName: T.className, owner: owner) as! T
}
class func fromNib(withName name: String, owner: AnyObject? = nil) -> UIView {
return Bundle.main.loadNibNamed(name, owner: owner, options: nil)![0] as! UIView
}
}
And now you add another extension to UIView to return another view of exact the same type:
extension UIView {
func getCopy() -> Self {
return UIView.fromNib()
}
}
You can even override this method in your subclasses to pass custom variables:
class MySubView: AnyParentView {
var testVariable: Int?
override func getCopy() -> MySubView {
let view = MySubView.fromNib()
view.testVariable = self.testVariable
return view
}
}
Now you can easily instantiate views and copy them while keeping their respective subtype. If the outlets are set correctly in the xib they will also be set for the new "copied" view instance. You can then pass it to your method that expects a UIView subclass.
Hope this helps!

Answer 3

Maybe the following might work? Have a nice day.
import Foundation
import UIKit
class MyView: UIView {
#IBOutlet weak var label: UILabel!
#IBOutlet weak var subLabel: UILabel!
required convenience init?(coder aDecoder: NSCoder) {
self.init()
self.label = aDecoder.decodeObject(forKey: "label") as? UILabel
self.subLabel = aDecoder.decodeObject(forKey: "subLabel") as? UILabel
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encode(self.label, forKey: "label")
aCoder.encode(self.subLabel, forKey: "subLabel")
}
}