UISearchController how to activate from SwiftUI - swiftui

Question

I found an integration of the uiSearchController in SwiftUI, but I don't know how to let it become active?
I found this:
I want that the searchBar becomes active when changing an Bool in the SwiftUI View with a #State for example.
If I add a Binding to the view modifier and set the isActive property of the searchController in
ViewControllerResolver { viewController in
viewController.navigationItem.searchController = self.searchBar.searchController
viewController.navigationItem.hidesSearchBarWhenScrolling = false
}
then is doesn't become active.
Im not really familiar with UIKit, perhaps anybody knows how to correctly activate the searchbar that one can start typing for a search.
class SearchBar: NSObject, ObservableObject {
#Published var text: String = ""
let searchController: UISearchController = UISearchController(searchResultsController: nil)
override init() {
super.init()
self.searchController.obscuresBackgroundDuringPresentation = false
self.searchController.searchResultsUpdater = self
}
}
extension SearchBar: UISearchResultsUpdating {
func updateSearchResults(for searchController: UISearchController) {
// Publish search bar text changes.
if let searchBarText = searchController.searchBar.text {
self.text = searchBarText
}
}
}
final class ViewControllerResolver: UIViewControllerRepresentable {
let onResolve: (UIViewController) -> Void
init(onResolve: #escaping (UIViewController) -> Void) {
self.onResolve = onResolve
}
func makeUIViewController(context: Context) -> ParentResolverViewController {
ParentResolverViewController(onResolve: onResolve)
}
func updateUIViewController(_ uiViewController: ParentResolverViewController, context: Context) {
}
}
class ParentResolverViewController: UIViewController {
let onResolve: (UIViewController) -> Void
init(onResolve: #escaping (UIViewController) -> Void) {
self.onResolve = onResolve
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
fatalError("Use init(onResolve:) to instantiate ParentResolverViewController.")
}
override func didMove(toParent parent: UIViewController?) {
super.didMove(toParent: parent)
if let parent = parent {
onResolve(parent)
}
}
}
struct SearchBarModifier: ViewModifier {
let searchBar: SearchBar
func body(content: Content) -> some View {
content
.overlay(
ViewControllerResolver { viewController in
viewController.navigationItem.searchController = self.searchBar.searchController
viewController.navigationItem.hidesSearchBarWhenScrolling = false
}
.frame(width: 0, height: 0)
)
}
}
extension View {
func add(_ searchBar: SearchBar) -> some View {
return self.modifier(SearchBarModifier(searchBar: searchBar))
}
}

Answer 1

To activate a UISearchBar (which is what you're using), just do:
searchController.searchBar.becomeFirstResponder()
(from this answer)
Now all we need to do is reference searchController.searchBar from the SwiftUI view. First, add a function to your SearchBar class.
class SearchBar: NSObject, ObservableObject {
#Published var text: String = ""
let searchController: UISearchController = UISearchController(searchResultsController: nil)
override init() {
super.init()
self.searchController.obscuresBackgroundDuringPresentation = false
self.searchController.searchResultsUpdater = self
}
/// add this function
func activate() {
searchController.searchBar.becomeFirstResponder()
}
}
Then, just call it. I think this is better than setting a #State, but if you require that, let me know and I'll edit my answer.
struct ContentView: View {
#StateObject var searchBar = SearchBar()
var body: some View {
NavigationView {
Button(action: {
searchBar.activate() /// activate the search bar
}) {
Text("Activate search bar")
}
.modifier(SearchBarModifier(searchBar: searchBar))
.navigationTitle("Navigation View")
}
}
}
Result: