How can I pass in a SwiftUI View in a function?

Question

The app I'm working on is predominantly in UIKit. We are starting to shift to SwiftUI for smaller components and I wanted to write a neat little extension which would take in a SwiftUI view and return the UIKit view. This is the code I currently have:

    static func getUIView(for swiftUIView: View) -> UIView {
        let hostingController = UIHostingController(rootView: swiftUIView)
        return hostingController.view
    }
}

However this throws an error

Protocol 'View' can only be used as a generic constraint because it has Self or associated type requirements

Could someone explain to me why this is a problem and what would be the right way of achieving this?

Answer 1

You simply need to make your method generic and restrict your generic type to View.

static func getUIView<V: View>(for swiftUIView: V) -> UIView {
    let hostingController = UIHostingController(rootView: swiftUIView)
    return hostingController.view
}

However, I'd rather suggest creating a computed property on View that returns a UIView from the view itself.

extension View {
    var uiView: UIView {
        UIHostingController(rootView: self).view
    }
}

And then call it on the View you want to convert to UIView:

Text("Label").uiView