How to copy an instance in Swift

Question

For example. I got a UISearchBar which I wanted to make a totally same copy.

I think it could be done by implementing the copy(with:) (copyWithZone:) of NSObject and then call the copy().

But what I don't know is what to do inside the copyWithZone in Swift.

I just need a copy of the UISearchController's UISearchBar.
Let's say we have a topic about how to copy an instance.
How to make that happen?

why you want to copy UISearchBar ? What is your requirement ? — vivekDas, Aug 11 '18 at 07:40
Do you mean to make another instance of a class? Please clarify what you are trying to achieve. — Chris, Aug 11 '18 at 07:44
Create a factory method instead or a configure function that takes a UISearchBar instance as an argument — Joakim Danielson, Aug 11 '18 at 07:52

AamirR · Accepted Answer · 2018-08-11T09:07:58.767

1

UISearchBar cannot be copied as it doesn't adopt NSCopying.

You have to create a new instance of UISearchBar and apply the customizations, for this you can also create an struct that holds the settings, like so:

struct SearchBarConfig {
    var placeholder: String?
    var isTranslucent: Bool

    // Display Attributes
    var barStyle: UIBarStyle
    var barTintColor: UIColor?
    var searchBarStyle: UISearchBarStyle
    var tintColor: UIColor!

    init(isTranslucent: Bool, barStyle: UIBarStyle, searchBarStyle: UISearchBarStyle) {
        self.isTranslucent = isTranslucent
        self.barStyle = barStyle
        self.searchBarStyle = searchBarStyle
    }
}

let existingSearchBar = UISearchBar()
var existingStatusBarConfig = SearchBarConfig(
    isTranslucent: existingSearchBar.isTranslucent,
    barStyle: existingSearchBar.barStyle,
    searchBarStyle: existingSearchBar.searchBarStyle)

Now if you have above implemented, you can just create a new searchBar and apply the attributes.

edited Aug 11 '18 at 09:07

answered Aug 11 '18 at 08:02

AamirR

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So there is no convenient way? – JsW Aug 11 '18 at 08:05
4

UISearchbar does inherit from NSObject. It doesnt adopt NSCopying though. – Sulthan Aug 11 '18 at 08:06
@JsW "Why UIView cannot adopt NSCopying"?, refer to this post https://stackoverflow.com/a/1552137, I like how Frank explained in this answer https://stackoverflow.com/a/1556426/1244597 – AamirR Aug 11 '18 at 08:14
1

`UIView` inherit from `UIResponder` which inherit from `NSObject` – JsW Aug 11 '18 at 08:30
@JsW Although UIView does inherit from NSObject (as almost all classes in Objective-C) do, that does not mean that it adopts the NSCopying protocol. – Abizern Aug 11 '18 at 11:31
@Abizern yeah, I realized it now :p – JsW Aug 11 '18 at 23:38

How to copy an instance in Swift

1 Answers1