ViewModelSearchable.swift

import Foundation
import SwiftUI

class SearchableViewModel: ObservableObject {
  let names = ["Oliver", "Emily", "Jessica", "Daniel", "Eva"]
  
  @Published var searchText: String = ""
  
  var searchResults: [String] {
    if searchText.isEmpty {
      return names
    } else {
      return names.filter { $0.lowercased().contains(searchText.lowercased()) }
    }
  }
  
  var isSearching = false
  
  var sectionTitle: String {
    isSearching ? "Searching" : "Not Searching"
  }
}

struct VMSearchableView: View {
  @ObservedObject var viewModel: SearchableViewModel
  
  var body: some View {
    NavigationView {
      VMSearchableList(viewModel: viewModel)
      .navigationBarTitle("Searchable")
      .searchable(
        text: $viewModel.searchText,
        prompt: "Search names..."
      )
    }
  }
}

struct VMSearchableList: View {
  @ObservedObject var viewModel: SearchableViewModel
  
  @Environment(\.isSearching) var isSearching
  
  var body: some View {
    List {
      Section(viewModel.sectionTitle) {
        ForEach(viewModel.searchResults, id: \.self) { name in
          Text(name)
        }
      }
    }
    .navigationBarTitle("Searchable")
    .onChange(of: isSearching) { newValue in
      viewModel.isSearching = newValue
    }
  }
}

struct VMSearchableView_Previews: PreviewProvider {
  static var previews: some View {
    VMSearchableView(viewModel: .init())
  }
}