SwiftUI Core Data 90 - 데이터 가져오기

#1. CoreDataManager,   getAllMovies() 함수 생성 

 

import Foundation

import CoreData

 

class CoreDataManager{

    

    let persistentContainer: NSPersistentContainer

    

    init(){

        

        persistentContainer = NSPersistentContainer(name: "HelloCoreDataModel")

        persistentContainer.loadPersistentStores{(description, error) in

            

            if let error = error {

                fatalError("Core Data Store failed to initialize \(error.localizedDescription)")

            }

            

        }

    }

    //Fetch

    func getAllMovies() -> [Movie]{

        

        let fetchRequest: NSFetchRequest<Movie> = Movie.fetchRequest()

        

        do{

           return try persistentContainer.viewContext.fetch(fetchRequest)

            

        } catch {

            return []

        }

    }

    

    

    //Save Entity

    func saveMovie(title: String){

        

        let movie = Movie(context: persistentContainer.viewContext)

        movie.title = title

        

        do{

            try persistentContainer.viewContext.save()

            print("Movie saved!")

        } catch{

            print("Failed to save movie", error )

        }

 

    }

    

}

 

#2. ContentView, populateMovies()함수로 데이터 가져오기

import SwiftUI

 

struct ContentView: View {

    

    let coreDM: CoreDataManager

    @State private var movieName: String = ""

    @State private var movies: [Movie] = [Movie]()

    

    //데이터 가져오기

    private func populateMovies(){

        movies = coreDM.getAllMovies()

    }

    

    var body: some View {

        

        VStack{

            TextField("Enter movie name", text: $movieName).textFieldStyle(RoundedBorderTextFieldStyle())

            Button("Save"){

                coreDM.saveMovie(title: movieName)

                populateMovies() //버튼이 눌렀을때 리스트뷰에 데이터 생성

                

            }

            List(movies, id:\.self){ movie in

                Text(movie.title ?? "")

            }

            Spacer()

            

        }.padding()

            .onAppear(perform: {

                populateMovies() //시작시 데이터 생성

            })

    }

}

 

struct ContentView_Previews: PreviewProvider {

    static var previews: some View {

        ContentView(coreDM: CoreDataManager())

    }

}