[Swift] Core Data 기초와 세팅

Core Data Fundamentals

Configure & Setup Core Data

1. 프로젝트 처음 시작할 때 Use Core Data 체크박스 체크

   

2. 프로젝트 중간에 넣고 싶다면?

   File - New - File - Data Model

   

   AppDelegate.swift 에 import CoreData 한 후 아래에 Core Data 템플릿 복붙하기

   // 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: "[FILE-NAME]")
           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)")
               }
           }
       }
   
   }

   (appWillTerminate에 self.saveContext() 넣어주기?.? 불확실)

3. set up

   

   • Module : Global이 아닌 Current Product Module로 선택하자

   • Codegen

     • Class Definition : class를 만드는 것과 같은 효과 (뒤에 code generation 다 됨)
     • Category/Extension : 직접 Entitiy와 같은 이름의 class를 만들면 Xcode가 자동으로 link (custom class 쓰고 싶을 때)
     • Manual/None : 아무 code generating을 해주지 않음!

Terminology

• Entitiy : Class (Table)
• Attributes : Properties

(참고) Codable

import Foundation

class Item: Codable {
    var title : String = ""
    var done : Bool = false
}

Core Data

Reference

사진출처 Photo Credit :

Udemy iOS 13 & Swift 5 - The Complete iOS App Development Bootcamp