Search bar not updating text in UI

Question

Created Dec ’20

Replies 2

Boosts 0

Views 1.4k

Participants 2

I have implemented a custom NavigationView with a search bar in SwiftUI.

The SearchResultsContent doesn’t update properly though. I can’t seem to figure out why.
I’ve done all the UISearchResultsUpdating related things, but that doesn’t fix the problem.

Code Block Swiftstruct SearchBarNavigationView<SearchResultsContent: View, Content: View>: UIViewControllerRepresentable {
	class Coordinator: NSObject, UISearchResultsUpdating {
		private let parent: SearchBarNavigationView
		init(_ parent: SearchBarNavigationView) {
			self.parent = parent
		}
		func updateSearchResults(for searchController: UISearchController) {
			guard let searchText = searchController.searchBar.text else { return }
			DispatchQueue.main.async { self.parent.text = searchText }
		}
	}
	@Binding private var text: String
	private let searchResultsContent: SearchResultsContent
	private let content: Content
	init(text: Binding<String>, @ViewBuilder searchResultsContent: () -> SearchResultsContent, @ViewBuilder content: () -> Content) {
		_text = text
		self.searchResultsContent = searchResultsContent()
		self.content = content()
	}
	func makeUIViewController(context: Context) -> UINavigationController {
		let rootViewController = UIHostingController(rootView: content)
		let navigationController = UINavigationController(rootViewController: rootViewController)
		navigationController.navigationBar.prefersLargeTitles = true
		
		let searchResultsController = UIHostingController(rootView: searchResultsContent)
		let searchController = UISearchController(searchResultsController: searchResultsController)
		searchController.searchResultsUpdater = context.coordinator
		searchController.obscuresBackgroundDuringPresentation = false
		searchController.searchBar.autocapitalizationType = .none
		navigationController.navigationBar.topItem?.searchController = searchController
		return navigationController
	}
	func updateUIViewController(_ uiViewController: UINavigationController, context: Context) {
		if let searchResultsController = uiViewController.navigationBar.topItem?.searchController?.searchResultsController as? UIHostingController<SearchResultsContent> {
			searchResultsController.rootView = searchResultsContent
			searchResultsController.view.setNeedsDisplay()
		}
		if let rootViewController = uiViewController.topViewController as? UIHostingController<Content> {
			rootViewController.rootView = content
			rootViewController.view.setNeedsDisplay()
		}
		uiViewController.navigationBar.topItem?.searchController?.searchBar.text = text
	}
	func makeCoordinator() -> Coordinator {
		Coordinator(self)
	}
}

Implementation in View

Code Block SwiftSearchBarNavigationView(text: $searchText) {
	Text(searchText) // doesn’t change whilst typing
} content: {
	List(0 ..< 20) {
		Text("Row \($0)")
	}
}
.ignoresSafeArea()
.onChange(of: searchText) { value in
	print(value) // works correctly
}

Answered by BabyJ in 652503022

It turns out I needed to change some code in the updateUIViewController(_:context:) method to reload the SearchResultsContent

Code Block Swiftif let searchResultsController = uiViewController.navigationBar.topItem?.searchController?.searchResultsController as? UIHostingController<SearchResultsContent> {
	searchResultsController.rootView = searchResultsContent
	searchResultsController.view.setNeedsDisplay()
}

Boost

Answer 1

OOPer OP

Dec ’20

With these two lines:

Code Block private let searchResultsContent: SearchResultsContent	
private let content: Content

you keep the result View which is built on initialization.

Try keeping the closures, and invoke them when needed:

Code Block private let searchResultsContent: ()->SearchResultsContent	
private let content: ()->Content

0

Answer 2

BabyJ OP

Dec ’20

Accepted Answer

It turns out I needed to change some code in the updateUIViewController(_:context:) method to reload the SearchResultsContent

Code Block Swiftif let searchResultsController = uiViewController.navigationBar.topItem?.searchController?.searchResultsController as? UIHostingController<SearchResultsContent> {
	searchResultsController.rootView = searchResultsContent
	searchResultsController.view.setNeedsDisplay()
}

0