How to Pass Textfield Value to View Controller Through Button Click in Swift Ui

How to pass Textfield value to view controller through button click in Swift UI

Here is a little sample. Like I said I don't have Google Ads in anything right now but it should be straightforward

import SwiftUI
struct TestAdsView: View {
    @StateObject var vm: AdsScreenViewModel = AdsScreenViewModel()
    var body: some View {
        VStack{
            Text(vm.adStatus.rawValue)
            TextField("adId", text: $vm.adUnitId)
            Button("load Ads", action: {
                vm.loadAds()
            })
            //You might have to play with the position of this.
            AdsScreenView_UI(viewModel: vm).frame(width: 0, height: 0)
        }
    }
}
//This is the source of truth the user input will be held here
class AdsScreenViewModel: ObservableObject, MyAdsViewModelProtocol{
    ///reference to UIKit
    var uiViewController: MyAdsViewControllerProtocol? = nil
    
    @Published var adUnitId: String = ""
    @Published var adStatus: AdStatus = .unknown
    //MARK: MyAdsViewControllerProtocol
    func loadAds() {
        print(#function)
        uiViewController?.loadAds()
    }
    
    func setAdStatus(adStatus: AdStatus) {
        print(#function)
        self.adStatus = adStatus
    }
    func getAdId() -> String {
        print(#function)
        return adUnitId
    }
    
}
struct AdsScreenView_UI: UIViewControllerRepresentable{
    @ObservedObject var viewModel: AdsScreenViewModel
    func makeUIViewController(context: Context) -> some AdsScreenViewController {
        print(#function)
        return AdsScreenViewController(viewModel: viewModel)
    }
    
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
        print(#function)
    }
}
//This can mirror the google sample
class AdsScreenViewController: UIViewController, MyAdsViewControllerProtocol {
    ///SwiftUI Delegate
    var viewModel: MyAdsViewModelProtocol
    
    init(viewModel: MyAdsViewModelProtocol) {
        print(#function)
        self.viewModel = viewModel
        super.init(nibName: nil, bundle: .main)
        //Link between UIKit and SwiftUI
        self.viewModel.uiViewController = self
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    override func viewDidLoad() {
        super.viewDidLoad()
        print(#function)
        viewModel.setAdStatus(adStatus: .initialized)
        //Put the current code you have here
    }
    //MARK: MyAdsViewModelProtocol
    func loadAds() {
        print(#function)
        print("ad id \(viewModel.getAdId())")
        viewModel.setAdStatus(adStatus: .loading)
        //You would load here not in viewDidLoad
    }
}
//Protocols aren't needed but it makes the code reusable and you can see the connection protocol = interface
protocol MyAdsViewModelProtocol{
    ///Reference to the google view controller
    var uiViewController: MyAdsViewControllerProtocol? { get set }
    
    ///Tells the viewController to load the ad
    func loadAds()
    ///Retrieves the AdId
    func getAdId() -> String
    ///Sets the Ad Status
    func setAdStatus(adStatus: AdStatus)
}
protocol MyAdsViewControllerProtocol: UIViewController{
    ///Reference to the SwiftUI ViewModel
    var viewModel: MyAdsViewModelProtocol { get set }
    ///Tells Google to load the ad
    func loadAds()
}
enum AdStatus: String{
    case initialized
    case loading
    case unknown
    case error
}

struct TestAdsView_Previews: PreviewProvider {
    static var previews: some View {
        TestAdsView()
    }
}

Return from SwiftUI to Storyboard with a SwiftUI button

A possible approach is to inject a closure with unwind action from a view controller via view model into SwiftUI view and call it inside SwiftUI view button.

Here is main part:

super.init(coder: coder, rootView: SecondView(vm: viewModel))
viewModel.unwind = { [weak self] in
   // call unwind segue created in storyboard
    self?.performSegue(withIdentifier: "unwind_segue_identifier", sender: self)
}

Complete findings and code here

Call UIKIT function from SWIFTUI

Here is a sample

class UserDashboardModel: ObservableObject {
    @Published var totalBalance     = 0.0
    internal var uIViewController: UserDashboardHostVC? = nil
    
    func getAcctBalance(){
        if uIViewController != nil{
            uIViewController!.getAcctBalance()
        }else{
            print("view controller is not connected")
        }
    }
}
struct UserDashboard: View {
    
    @ObservedObject var userModel: UserDashboardModel
    var body: some View{
        VStack{
            Button(action: {
                userModel.getAcctBalance() //Call shared model
            }){
                Text("Load Balance")
            }
            
            Text(userModel.totalBalance.description) //Now it will change
        }.frame(width: 400, height: 400, alignment: .center)
    }
}
class UserDashboardHostVC: UIViewController {
    
    var userModel = UserDashboardModel()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        //Crucial connection
        userModel.uIViewController = self
        let controller = UIHostingController(rootView: UserDashboard(userModel: self.userModel))
        
        self.addChild(controller)
        self.view.addSubview(controller.view)
        controller.view.translatesAutoresizingMaskIntoConstraints = false
        //Update constraints per use case
        controller.view.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
        controller.view.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
        controller.didMove(toParent: self)
        
    }
    func getAcctBalance() {
        userModel.totalBalance = 599
    }
}

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