UIKit - CoreData 프로젝트 설정 및 엔티티 생성하기

1. 프로젝트 생성 시 Core Data 사용 설정

이미 생성된 프로젝트에는 새로운 Data Model 파일을 생성하여 처리 가능함. 단 AppDelegate에 아래에서 나오는 코드를 직접 설정해줘야함.

2. 프로젝트 이름으로 생성된 Data Model 클래스에 접근하여 Entity 생성

3. 생성된 Entity명을 용도에 맞게 변경한 후 Attribute 설정

4. 직접 Entity 파일을 생성할 것이기 때문에 Codegen 설정 None으로 변경

Codegen을 None으로 설정해야 Xcode가 자동으로 클래스를 생성하는 걸 막고, 개발자가 직접 만든 Entity 클래스가 충돌 없이 사용됨.

5. Editor > Create NSManagedObject Subclass를 클릭하여 Entity 클래스 생성

6. 생성된 Entity 클래스 확인

7. AppDelegate에 생성된 코드 확인

AppDelegate.swift

import UIKit
import CoreData

@main
class AppDelegate: UIResponder, UIApplicationDelegate {

    // MARK: - Core Data stack

    lazy var persistentContainer: NSPersistentContainer = {
        /*
         The persistent container for the application. This implementation
         creates and returns a container, having loaded the store for the
         application to it. This property is optional since there are legitimate
         error conditions that could cause the creation of the store to fail.
        */
        let container = NSPersistentContainer(name: "CoreDataCreateProject")
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                 
                /*
                 Typical reasons for an error here include:
                 * The parent directory does not exist, cannot be created, or disallows writing.
                 * The persistent store is not accessible, due to permissions or data protection when the device is locked.
                 * The device is out of space.
                 * The store could not be migrated to the current model version.
                 Check the error message to determine what the actual problem was.
                 */
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
        return container
    }()

    // MARK: - Core Data Saving support

    func saveContext () {
        let context = persistentContainer.viewContext
        if context.hasChanges {
            do {
                try context.save()
            } catch {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
                let nserror = error as NSError
                fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
            }
        }
    }
}