Part 16 of building the NavigationSearch.

NavigationSearch(12).swift

import SwiftUI
import UIKit

extension View {
    func navigationSearch(text: Binding<String>, onCancelButtonClicked: @escaping () -> Void = {}, onSearchButtonClicked: @escaping () -> Void = {}) -> some View {
        overlay(NavigationSearch<AnyView>(text: text, onCancelButtonClicked: onCancelButtonClicked, onSearchButtonClicked: onSearchButtonClicked).frame(width: 0, height: 0))
    }
    
    func navigationSearch<SearchResultsContent>(text: Binding<String>, onCancelButtonClicked: @escaping () -> Void = {}, onSearchButtonClicked: @escaping () -> Void = {}, @ViewBuilder searchResultsContent: @escaping () -> SearchResultsContent) -> some View where SearchResultsContent : View {
        overlay(NavigationSearch<SearchResultsContent>(text: text, onCancelButtonClicked: onCancelButtonClicked, onSearchButtonClicked: onSearchButtonClicked, searchResultsContent: searchResultsContent).frame(width: 0, height: 0))
    }
}

struct NavigationSearch<SearchResultsContent>: UIViewControllerRepresentable where SearchResultsContent : View {
    typealias UIViewControllerType = Wrapper
    
    @Binding var text: String
    
    private let onCancelButtonClicked: () -> Void
    private let onSearchButtonClicked: () -> Void
    
    private let searchResultsContent: () -> SearchResultsContent?

    init(text: Binding<String>, onCancelButtonClicked: @escaping () -> Void = {}, onSearchButtonClicked: @escaping () -> Void = {}, @ViewBuilder searchResultsContent: @escaping () -> SearchResultsContent? = { nil }) {
        self._text = text
        self.onCancelButtonClicked = onCancelButtonClicked
        self.onSearchButtonClicked = onSearchButtonClicked
        self.searchResultsContent = searchResultsContent
    }
    
    func makeCoordinator() -> Coordinator {
        Coordinator(representable: self)
    }

    func makeUIViewController(context: Context) -> Wrapper {
        Wrapper()
    }
    
    func updateUIViewController(_ wrapper: Wrapper, context: Context) {
        wrapper.searchController = context.coordinator.searchController
        wrapper.searchController?.searchBar.text = text
        wrapper.navigationBarSizeToFit()
        
        if let searchResultsContent = self.searchResultsContent() {
            (wrapper.searchController?.searchResultsController as? UIHostingController<SearchResultsContent>)?.rootView = searchResultsContent
        }
    }
    
    class Coordinator: NSObject, UISearchResultsUpdating, UISearchBarDelegate {
        let representable: NavigationSearch
        
        let searchController: UISearchController
        
        init(representable: NavigationSearch) {
            self.representable = representable
            
            var searchResultsController: UIViewController? = nil

            if let searchResultsContent = representable.searchResultsContent() {
                searchResultsController = UIHostingController(rootView: searchResultsContent)
            }

            self.searchController = UISearchController(searchResultsController: searchResultsController)
            
            super.init()
            self.searchController.searchResultsUpdater = self
            self.searchController.searchBar.delegate = self
            self.searchController.searchBar.text = representable.text
        }
        
        // MARK: - UISearchResultsUpdating
        func updateSearchResults(for searchController: UISearchController) {
            guard let text = searchController.searchBar.text else { return }
            DispatchQueue.main.async { [weak self] in self?.representable.text = text }
        }
        
        // MARK: - UISearchBarDelegate
        func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
            DispatchQueue.main.async { self.representable.onCancelButtonClicked() }
        }

        func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
            DispatchQueue.main.async { self.representable.onSearchButtonClicked() }
        }
    }
    
    class Wrapper: UIViewController {
        var searchController: UISearchController? {
            get {
                self.parent?.navigationItem.searchController
            }
            set {
                self.parent?.navigationItem.searchController = newValue
            }
        }
        
func navigationBarSizeToFit() {
    self.parent?.navigationController?.navigationBar.sizeToFit()
}
    }
}