SwiftUI MVVM (Model View View Model) design pattern

SwiftUI MVVM (Model View View Model) design pattern with ObservableObject — @Published — @ObservedObject fetch JSON data

ContentView.swift

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

// //  ContentView.swift //  SwiftUIProject // //  Created by Cairocoders //   import SwiftUI   struct ContentView: View {          @ObservedObject var viewModel = ContentViewModel()          var body: some View {       NavigationView {           VStack {               List(viewModel.items, id: \.id) { item in                    VStack(alignment: .leading) {                       Text(item.title)                       Text(item.completed.description)                         .font(.system(size: 11))                         .foregroundColor(.gray)                    }               }               .listStyle(GroupedListStyle())                           }.onAppear(perform: {              viewModel.fetchData()           })         .navigationBarTitle("Fetch JSON Datas")       }    } }   struct ContentView_Previews: PreviewProvider {     static var previews: some View {         ContentView()     } }

ViewModel.swift

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

// //  ViewModel.swift //  SwiftUIProject // //  Created by Cairocoders //   import SwiftUI   class ContentViewModel: ObservableObject {   @Published var items = [Model]()   func fetchData() {     let api = "https://jsonplaceholder.typicode.com/todos"     guard let url = URL(string: api) else { return }     URLSession.shared.dataTask(with: url) { (data, response, error) in       do {          if let data = data {            let result = try JSONDecoder().decode([Model].self, from: data)            DispatchQueue.main.async {               self.items = result            }          } else {            print("No data")          }       } catch (let error) {          print(error.localizedDescription)       }      }.resume()   } }

Model.swift

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

// //  Model.swift //  SwiftUIProject // //  Created by Cairocoders //   import SwiftUI   struct Model: Decodable {    let id: Int    let userId: Int    let title: String    let completed: Bool }