Is there any way to use storyboard and SwiftUI in same iOS Xcode project?

Question

As Swift 5 introduces the SwiftUI framework for creating the views, but we are currently using the storyboard for UI design.

So I just wanted to know the procedure to use Storyboard and Swift UI in same iOS Single View Application.

Answer 1

I just started to look at the SwiftUI. Sharing a small example.

1. In the storyboard add Hosting View Controller
2. Subclass the UIHostingController with your own class (ChildHostingController)
3. ChildHostingController should look something like that:

import UIKit
import SwiftUI

struct SecondView: View {
  var body: some View {
      VStack {
          Text("Second View").font(.system(size: 36))
          Text("Loaded by SecondView").font(.system(size: 14))
      }
  }
}

class ChildHostingController: UIHostingController<SecondView> {
   
    required init?(coder: NSCoder) {
        super.init(coder: coder, rootView: SecondView())
    }
       
    override func viewDidLoad() {
        super.viewDidLoad()
    }
}

For more details have a look at Custom UIHostingController
Apple Docs UIhostingController (Unfortunatelly it hasn't been documented yet)
Integrating SwiftUI Video

Answer 2

Add SwiftUI to a UIKit project:

1) Display a complete screen from SwiftUI:

If this is your case, you need just to follow this article or check one of the above answers.

2) Add SwiftUI view inside UIViewController:

In this case, follow the following steps:

1. Add this extension to your project:

This extension is copy pasted from a scale project in production:

import UIKit
import SwiftUI

extension UIViewController {
    /// component: View created by SwiftUI
    /// targetView: The UIView that will host the component
    func host(component: AnyView, into targetView: UIView) {
        let controller = UIHostingController(rootView: component)
        self.addChild(controller)
        controller.view.translatesAutoresizingMaskIntoConstraints = false
        targetView.addSubview(controller.view)
        controller.didMove(toParent: self)

        NSLayoutConstraint.activate([
            controller.view.widthAnchor.constraint(equalTo: targetView.widthAnchor, multiplier: 1),
            controller.view.heightAnchor.constraint(equalTo: targetView.heightAnchor, multiplier: 1),
            controller.view.centerXAnchor.constraint(equalTo: targetView.centerXAnchor),
            controller.view.centerYAnchor.constraint(equalTo: targetView.centerYAnchor)
        ])
    }
}

2. Use the extension inside your viewDidLoad:

import UIKit
import SwiftUI

class ViewController: UIViewController {

    // MARK: - Outlets

    // This view should have the needed constraints
    // bc we are going to magically convert it to your `SwiftUI` view!
    @IBOutlet weak var myUIView: UIView!

    // MARK: - Life Cycle

    override func viewDidLoad() {
        super.viewDidLoad()

        // Create instance from your `SwiftUI` view
        let mySwiftUIView = SomeAmazingView()

        // Use the extension
        self.host(component: AnyView(mySwiftUIView), into: myUIView)
    }
}

That's all, good luck!

Answer 3

Mixing UIKit with SwiftUI

Both can be embedded and mixed SwiftUI in Storyboards and the other way around

UIViewControllerRepresentable used for embedding Storyboards in SwiftUI

Create the ViewController on a Storyboard and give it a Storyboard ID

import SwiftUI

struct ContentView: View {
    var body: some View {
        StoryboardViewController()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

struct StoryboardViewController: UIViewControllerRepresentable {
    func makeUIViewController(context: Context) -> some UIViewController {
        let storyboard = UIStoryboard(name: "Storyboard", bundle: Bundle.main)
        let controller = storyboard.instantiateViewController(identifier: "Main")
        return controller
    }
    
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
        
    }
}

Communication between UIKit and SwiftUI can be through @Binding variable. This will let SwiftUI view inject variable state and control the it, func updateUIViewController will be called to do the work when changed.

UIViewRepresentable used same way for views

import SwiftUI

struct ContentView: View {
    @State var color = UIColor.green
    
    var body: some View {
        SampleView(color: $color).frame(width: 100, height: 100
                                        , alignment: .center)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}


struct SampleView: UIViewRepresentable {
    @Binding var color: UIColor
    
    func makeUIView(context: Context) -> some UIView {
        return UIView()
    }
    
    func updateUIView(_ uiView: UIViewType, context: Context) {
        uiView.backgroundColor = color
    }
}

UIHostingController used for embedding SwiftUI in UIKit

First is to be created programmatically

let childViewController = UIHostingController(rootView: SwiftUIContentView())
addChild(childViewController)
childViewController.view.frame = frame
view.addSubview(childViewController.view)
childViewController.didMove(toParent: self)

Second with Xcode 11 by adding Hosting View Controller to the storyboard and create a segue to it and then create an @IBSegueAction by Control-drag from the segue to your ViewController and then create an instance of the SwiftUI view and pass it to HostingViewController initializer

Third is by adding Hosting View Controller to the storyboard and then subclassing it as mentioned in the previous answer above https://stackoverflow.com/a/58250271/3033056

Answer 4

Yes you can do that! Here are the steps you can take to do so:

1. Go to your current Xcode project -> Storyboard, click on the + sign (right upper corner) and search for Hosting Controller (just like you would for a button or label).

2. Drag Hosting Controller to your Storyboard. Create a Segue connection from your UI element (I'm using a button) to that Hosting Controller and select Push. Create an outlet connection from that Segue to your View Controller (it's a new feature - just like you would create an outlet for a Label), and name it.

3. Declare your view inside of this outlet connection (you can do that, don't have to use PrepareForSegue method), and return it.

For example: I created a SwiftUI view in my current project (in Xcode: File -> New -> File -> SwiftUI View) and called it DetailsView. My outlet connection would look like this:

import UIKit 
import SwiftUI

class ViewController: UIViewController {

    @IBSegueAction func showDetails(_ coder: NSCoder) -> UIViewController? {
        let detailsView = DetailsView()
        return UIHostingController(coder: coder, rootView: detailsView)
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        // some code

    }
}

That's it! Now run it.

Answer 5

as Edgell Mentioned, there is a new ViewController named HostViewController that can host a SwiftUI page inside it. there's a complete talk about integrating SwiftUI in existing project at WWDC that answers your question very well.

Integrating SwiftUI: https://developer.apple.com/videos/play/wwdc2019/231/

WWDC19: https://developer.apple.com/videos/

Answer 6

You need to add a "Host View Controller" to the Storyboard. The SwiftUI form will be displayed in the Host View Controller and is callable from any Storyboard Form.

Be advised, the Host View Controller does not display in the Library for Xcode 11 on Mohave, you must be on Catalina. This is a bug, because once you have a project with a Host View Controller created on Catalina, that same project will run fine on Mohave, in fact, you can even copy that Host View Controller to other Storyboards and it will wok fine.