/swiftui-patterns

UIKit Interoperability

UIViewRepresentable

Use for: Wrapping UIKit views in SwiftUI

struct WebView: UIViewRepresentable {
    let url: URL
    @Binding var isLoading: Bool

    func makeUIView(context: Context) -> WKWebView {
        let webView = WKWebView()
        webView.navigationDelegate = context.coordinator
        return webView
    }

    func updateUIView(_ webView: WKWebView, context: Context) {
        let request = URLRequest(url: url)
        webView.load(request)
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(isLoading: $isLoading)
    }

    class Coordinator: NSObject, WKNavigationDelegate {
        @Binding var isLoading: Bool

        init(isLoading: Binding<Bool>) {
            _isLoading = isLoading
        }

        func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
            isLoading = true
        }

        func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
            isLoading = false
        }
    }
}

// Usage
struct ArticleWebView: View {
    let url: URL
    @State private var isLoading = false

    var body: some View {
        WebView(url: url, isLoading: $isLoading)
            .overlay {
                if isLoading {
                    ProgressView()
                }
            }
    }
}

UIViewControllerRepresentable

Use for: Presenting UIKit view controllers

struct ImagePicker: UIViewControllerRepresentable {
    @Binding var image: UIImage?
    @Environment(\.dismiss) private var dismiss

    func makeUIViewController(context: Context) -> PHPickerViewController {
        var config = PHPickerConfiguration()
        config.filter = .images
        config.selectionLimit = 1

        let picker = PHPickerViewController(configuration: config)
        picker.delegate = context.coordinator
        return picker
    }

    func updateUIViewController(_ uiViewController: PHPickerViewController, context: Context) {
        // No updates needed
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(image: $image, dismiss: dismiss)
    }

    class Coordinator: NSObject, PHPickerViewControllerDelegate {
        @Binding var image: UIImage?
        let dismiss: DismissAction

        init(image: Binding<UIImage?>, dismiss: DismissAction) {
            _image = image
            self.dismiss = dismiss
        }

        func picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult]) {
            dismiss()

            guard let provider = results.first?.itemProvider else { return }

            if provider.canLoadObject(ofClass: UIImage.self) {
                provider.loadObject(ofClass: UIImage.self) { image, _ in
                    DispatchQueue.main.async {
                        self.image = image as? UIImage
                    }
                }
            }
        }
    }
}

// Usage
struct ProfileEditView: View {
    @State private var profileImage: UIImage?
    @State private var showImagePicker = false

    var body: some View {
        VStack {
            if let image = profileImage {
                Image(uiImage: image)
                    .resizable()
                    .aspectRatio(contentMode: .fill)
                    .frame(width: 200, height: 200)
                    .clipShape(Circle())
            }

            Button("Choose Photo") {
                showImagePicker = true
            }
        }
        .sheet(isPresented: $showImagePicker) {
            ImagePicker(image: $profileImage)
        }
    }
}