[MVVM] MVVM 예제1

• Model

  struct WeatherModel : Codable {
    let timezone : String
    let current : CurrentWeather
  }
  struct CurrentWeather : Codable {
    let temp : Float
    let weather : [WeatherInfo]
  }
  struct WeatherInfo : Codable {
    let main : String
    let description : String
  }

• ViewModel

  class WeatherViewModel: ObservableObject {
    @Published var title : String = "-"
    @Published var descriptionText : String = "-"
    @Published var temp : String = "-"
    @Published var timezone : String = "-"
  
    init() {
        fetchWeather()
    }
    func fetchWeather() {
        guard let url = URL(string: "https://api.openweathermap.org/data/2.5/onecall?exclude=hourly.daily.minutely&lat=40.7128&lon=-74&units=imperial&appid=a25ffc3abde70c25f3d7f331151a9e3f") else {
            return
        }
        let task = URLSession.shared.dataTask(with: url) { data, _, error in
            guard let data = data, error == nil else{
                return
            }
            do {
                let model = try JSONDecoder().decode(WeatherModel.self, from : data)
  
                DispatchQueue.main.async {
                    self.title = model.current.weather.first?.main ?? "No Title"
                    self.descriptionText = model.current.weather.first?.main ?? "No Desciption"
                    self.temp =  "\(model.current.temp)º"
                    self.timezone = model.timezone
                }
            }
            catch {
                print("failed")
            }
            //Convert data to Model
        }
        task.resume()
    }
  }

• View

  struct ContentView: View {
    @StateObject var viewModel = WeatherViewModel()
  
    var body: some View {
        NavigationView{
            VStack{
                Text(viewModel.timezone).font(.system(size: 32))
                Text(viewModel.temp).font(.system(size: 44))
                Text(viewModel.title).font(.system(size: 24))
                Text(viewModel.descriptionText).font(.system(size: 24))
            }
            .navigationTitle("Weather MVVM")
        }
    }
  }
  struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            ContentView()
                .preferredColorScheme(.dark)
            ContentView()
                .preferredColorScheme(.dark)
        }
  
    }
  }

완성된 화면

reference

IOS Academy