SwiftUI search field with a keyboard focus binding

SearchField.swift

// ⚠️ As of WWDC21 you can use SwiftUI .searchable
// https://developer.apple.com/documentation/swiftui/list/searchable(text:placement:)
//
//  SearchField.swift
//
//  Created by Clarko on 7/17/20.
//
//  SwiftUI doesn't have a SearchField yet, so here's one from UIKit.
//
//  The isEditing binding lets you react to keyboard focus changes,
//  or control the state of keyboard focus yourself.
//

import SwiftUI

struct SearchField: UIViewRepresentable {
    var title: String
    @Binding var text: String
    @Binding var isEditing: Bool

    init(_ title: String, text: Binding<String>, isEditing: Binding<Bool>) {
        self.title = title
        self._text = text
        self._isEditing = isEditing
    }

    func makeUIView(context: UIViewRepresentableContext<SearchField>) -> UISearchBar {
        let uiSearchBar = UISearchBar()

        // Customize appearance
        uiSearchBar.autocapitalizationType = .none
        uiSearchBar.autocorrectionType = .default
        uiSearchBar.enablesReturnKeyAutomatically = false
        uiSearchBar.keyboardType = .default
        uiSearchBar.returnKeyType = .done
        uiSearchBar.searchBarStyle = .minimal

        uiSearchBar.delegate = context.coordinator
        return uiSearchBar
    }

    func updateUIView(_ uiView: UISearchBar, context: UIViewRepresentableContext<SearchField>) {
        // SwiftUI doesn't like it when you modify state during a view update
        context.coordinator.safeToModifyState = false

        uiView.text = text
        uiView.placeholder = title
        if isEditing {
            uiView.becomeFirstResponder()
        } else {
            uiView.resignFirstResponder()
        }

        context.coordinator.safeToModifyState = true
    }

    func makeCoordinator() -> SearchField.Coordinator {
        return Coordinator(text: $text, isEditing: $isEditing)
    }

    class Coordinator: NSObject, UISearchBarDelegate {
        @Binding var text: String
        @Binding var isEditing: Bool
        var safeToModifyState = true

        init(text: Binding<String>, isEditing: Binding<Bool>) {
            _text = text
            _isEditing = isEditing
        }

        func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
            if safeToModifyState {
                text = searchText
            }
        }

        func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {
            if safeToModifyState {
                isEditing = false
            }
        }

        func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
            if safeToModifyState {
                isEditing = true
            }
        }

        func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {
            if safeToModifyState {
                isEditing = false
            }
        }
        
    }
}