[✨ FEAT] : CloudKit Manager 생성

[GroundDev]

작업내용

• CloudKit 관련한 작업들을 총괄하는 코드를 작성해보겠습니다.
• 심층적인 개념 이해는 없이 무지성 클론코딩이 될 예정이므로, 아직 develop 브랜치에 merge시키지는 않겠습니다.

스크린샷

UI 작업은 없습니다.

Reference

레퍼런스는 그때그때 올릴게요.

[GroundDev]

https://developer.apple.com/documentation/coredata/mirroring_a_core_data_store_with_cloudkit/setting_up_core_data_with_cloudkit

위에서 제시하는 순서대로 아래의 코드를 AppDelegate.swift에 추가하였습니다.

import UIKit
import CoreData
import CloudKit

@main
class AppDelegate: UIResponder, UIApplicationDelegate {

    lazy var persistentContainer: NSPersistentCloudKitContainer = {
    
        let container = NSPersistentCloudKitContainer(name: "GiveCake")
        container.loadPersistentStores(completionHandler: {
            (storeDescription, error) in
            if let error = error as NSError? {
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
        return container
    }()
...

[GroundDev]

https://www.raulferrergarcia.com/en/develop-a-todo-app-with-cloudkit/

다만 중간에 .perfrom()함수가 fetch()함수로 대체된다고 합니다.

    /// `CKQueryOperation` is the more configurable, `CKOperation`-based alternative to this method
    ///
    /// Queries can potentially return a large number of records, and the server will return those records in batches.  This API may return a `queryCursor` which can be used to continue the query via the `fetch(withCursor:)` function.
    ///
    /// The successful result of this function includes a dictionary mapping matched record IDs to the fetched record.
    ///
    /// If a record fails in post-processing (say, a network failure materializing a `CKAsset` record field), the record ID will map to a per-record error instead
    ///
    /// - Parameter zoneID: Declares which zone the query should target.  Nil indicates "perform query across all zones in the database"
    /// Queries invoked within a `sharedCloudDatabase` must specify a `zoneID`; cross-zone queries are not supported in a `sharedCloudDatabase`
    /// - Parameter desiredKeys: Declares which user-defined keys should be fetched and added to the resulting `CKRecord`s.  If `nil`, declares the entire record should be downloaded. If set to an empty array, declares that no user fields should be downloaded.
    /// - Parameter resultsLimit: If set, requests that the server limit the number of matched records sent in any one response.  The server may choose to set its own limit lower than this value.
    @available(macOS 12.0, iOS 15.0, tvOS 15.0, watchOS 8.0, *)
    public func fetch(withQuery query: CKQuery, inZoneWith zoneID: CKRecordZone.ID? = nil, desiredKeys: [CKRecord.FieldKey]? = nil, resultsLimit: Int = CKQueryOperation.maximumResults, completionHandler: @escaping (Result<(matchResults: [(CKRecord.ID, Result<CKRecord, Error>)], queryCursor: CKQueryOperation.Cursor?), Error>) -> Void)

[SeonJeon]

https://www.raulferrergarcia.com/en/develop-a-todo-app-with-cloudkit/

다만 중간에 .perfrom()함수가 fetch()함수로 대체된다고 합니다.

    /// `CKQueryOperation` is the more configurable, `CKOperation`-based alternative to this method
    ///
    /// Queries can potentially return a large number of records, and the server will return those records in batches.  This API may return a `queryCursor` which can be used to continue the query via the `fetch(withCursor:)` function.
    ///
    /// The successful result of this function includes a dictionary mapping matched record IDs to the fetched record.
    ///
    /// If a record fails in post-processing (say, a network failure materializing a `CKAsset` record field), the record ID will map to a per-record error instead
    ///
    /// - Parameter zoneID: Declares which zone the query should target.  Nil indicates "perform query across all zones in the database"
    /// Queries invoked within a `sharedCloudDatabase` must specify a `zoneID`; cross-zone queries are not supported in a `sharedCloudDatabase`
    /// - Parameter desiredKeys: Declares which user-defined keys should be fetched and added to the resulting `CKRecord`s.  If `nil`, declares the entire record should be downloaded. If set to an empty array, declares that no user fields should be downloaded.
    /// - Parameter resultsLimit: If set, requests that the server limit the number of matched records sent in any one response.  The server may choose to set its own limit lower than this value.
    @available(macOS 12.0, iOS 15.0, tvOS 15.0, watchOS 8.0, *)
    public func fetch(withQuery query: CKQuery, inZoneWith zoneID: CKRecordZone.ID? = nil, desiredKeys: [CKRecord.FieldKey]? = nil, resultsLimit: Int = CKQueryOperation.maximumResults, completionHandler: @escaping (Result<(matchResults: [(CKRecord.ID, Result<CKRecord, Error>)], queryCursor: CKQueryOperation.Cursor?), Error>) -> Void)

이 부분은 어떤 용도로 쓰이는건가요?? 올려주신 레퍼런스에 같은 코드가 기입되있지 않은거 같아 잘 이해가 안갑니다 ㅠ

[GroundDev]

@SeonJeon
아 네! 위의 fetch 함수는 결국 쓰이지 않았습니다.
https://nsios.tistory.com/176
https://nsios.tistory.com/177
CloudKit manager는 위의 블로글을 참고해서 구현했어요.
CloudKit 이용하는 것 자체를 이해하지 못해서 아직 설명을 못했습니다
코드가 정리가 안되어 있다보니...
조만간 코드를 깔끔하게 정리하고 다시 이 부분 연재 시작해볼게요!

결론은 맞습니다 fetch함수는 쓰이지 않았어요.
참고로 위와 같은 함수가 어디있는지 알고 싶다면, command + 마우스 좌클릭을 하시면 Jump to Definition을 누르는게 나오게 되고


누르시면 아 이러이러한 구조로 쓰이는 녀석이구나 알 수 있습니다.
다만, 내부가 정확히 어떤 구조인지는 나타나있지 않아요. 이건 애플이 숨겨놨습니다. 함수가 정확히 어떤 내부를 갖고 있는 건지 궁금하시면 애플 UIKit 개발 부서로 입사하시면 됩니다!ㅎ 저희는 그저 이 함수가 어떤 용도인지, 어떻게 쓰면 되는지만 알 수 있습니다.