Slide Show Dot Indicator - SwiftUI

Question

I'm trying to build an image slideshow using Tab View with a custom Dot indicator based on UIPageControl but the dots are never displayed. Indeed the call to create the dot indicator is executed only once at the start of view creation

The images in the tabview are loaded based on the response received from an API request, which seems to be working really well but the call to create/update the PageControl that constructs the dot indicator never works after the data/count is updated. I see that it's getting called once when the view is constructed but any changes to the ObservedObject which updates the maximum Image count doesn't redraw the UIPageControl

I would like some advice to identify the issue in my code.

Thanks

This is the code that constructs the View

`

import SwiftUI

class DotIndicator: ObservableObject {
    @Published var maxImages = 0
    @Published var selectedImageIndex = 0
}


struct HomePageView: View {
    
    @State var appConfigurations = AppConfigData(infoPages: [], approvals: [])
    
    @ObservedObject var slideIndicator = DotIndicator()
    
    var body: some View {
        ZStack{
            BackgroundEffect()
            VStack{
                NavigationBar()
                
                Spacer().frame(height:0)
                
                TabView{
                    ForEach(appConfigurations.infoPages ?? [], id: \.key){infoPage in
                        AsyncImage(url: URL(string: infoPage.bannerImage ?? "")){ phase in
                            switch phase{
                            case .empty:
                                ProgressView()
                                    .progressViewStyle(.circular)
                            case .success(let image):
                                image.resizable()
                                    .aspectRatio(contentMode: .fill)
                            case .failure:
                                Image("megatrends-image")
                            @unknown default:
                                EmptyView()
                            }
                        }.tag(infoPage)
                        .frame(width: ScreenWidth(), height: ScreenHeight() * 0.32)
                    }
                }
                .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
                .frame(width: ScreenWidth(), height: ScreenHeight() * 0.32)
                .task {
                    appConfigurations = await getAppConfig()
                    
                    slideIndicator.maxImages = appConfigurations.infoPages?.count ?? 0
                    
                    slideIndicator.selectedImageIndex = 0
                }
                
                Spacer().frame(height:18)
                
                PageControl(maxImages: $slideIndicator.maxImages, currentImage: $slideIndicator.selectedImageIndex)

                Spacer().frame(height:58)
                
                CallBackButtons()
                
                Spacer()
                
                CreateTicketButton()
            }
        }
    }
}

`

And here's the code that controls the UIPageControl creation

`

import Foundation

import SwiftUI

struct PageControl: UIViewRepresentable{
    
    @Binding var maxImages: Int
    @Binding var currentImage: Int
    
    func makeUIView(context: Context) -> UIPageControl {
        
        print("Calling")
        
        let control = UIPageControl()
        control.backgroundStyle = .minimal
        control.numberOfPages = maxImages
        control.currentPage = currentImage
        control.currentPageIndicatorTintColor = UIColor.blue
        control.pageIndicatorTintColor = UIColor.black
        control.backgroundColor = UIColor.clear
        control.isUserInteractionEnabled = false
        
        return control
    }
    
    func updateUIView(_ uiView: UIPageControl, context: Context) {
        uiView.currentPage = currentImage
    }
}

`

Answer 1

I just figured it out, posting the answer here :

I had to set the number of pages again in the UpdateUIView

func updateUIView(_ uiView: UIPageControl, context: Context) {
    
    uiView.numberOfPages = maxImages
    uiView.currentPage = currentImage
}