1
以下のブロック引用文に記載されている述語でフェッチ要求を行っていますが、 "論理的にフェッチ要求を取得する"ようです。このメッセージは何を意味し、問題を見つけてそれを解決するためにどのような措置を取る必要がありますか？論理的にフェッチ取得要求
注釈：要求（：国;述語：エンティティ（ "alpha3Code" == "KOR"）; sortDescriptors：（（NULL））;タイプ：NSManagedObjectResultType;）フェッチ論理的に偽の短絡を。
ここでは、私は次のように通貨のクラスがある
let record = Currency.fetch(id: currency)[0] as! Currency
からエラーを取得するコードです。 NSManagedObjectProtocolはトレイト
extension NSManagedObjectProtocol {
public static func add(from objectValue: Dictionary<String, Any>) -> NSManagedObjectProtocol? {
let exists = fetch(id: objectValue)
if exists.count > 0 {
NSLog("Object already exists in CoreData : %@", objectValue.description)
return nil
} else {
return newObject(object: objectValue)
}
}
public static func addOrChange(from object: Dictionary<String, Any>) -> NSManagedObjectProtocol {
let exists = fetch(id: object)
if exists.count > 0 {
// TODO: confirm if data needs to be changed rather than delete and insert
}
delete(id: object)
return add(from: object)!
}
public static func getString(from object: Dictionary<String, Any>, withKeyValue key: String) -> String {
return object[key] as! String
}
public static func getInt16(from object: Dictionary<String, Any>, withKeyValue key: String) -> Int16 {
if let stringValue = object[key] as? String {
if let intValue = Int(stringValue) {
return Int16(intValue)
} else {
return 0
}
} else if let intValue = object[key] as? Int {
return Int16(intValue)
} else {
return 0
}
}
public static func getBool(from object: Dictionary<String, Any>, withKeyValue key: String) -> Bool {
if let boolValue = object[key] as? Bool {
return boolValue
} else {
return false
}
}
public static func fetch(predicates: [NSPredicate] = [], sortDescriptors: [NSSortDescriptor] = []) -> [Any] {
let request = Self.request(predicates: predicates)
do {
return try CoreDataHelper.getCoreDataHelper().context.fetch(request)
} catch {
return []
}
}
public static func fetch(id: Dictionary<String, Any>) -> [Any] {
return Self.fetch(predicates: Self.getPredicates(forID: id))
}
public static func delete(predicates: [NSPredicate] = []) {
let context = CoreDataHelper.getContext()
let fetchRequest = request(predicates: predicates)
let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
do {
try context.execute(deleteRequest)
CoreDataHelper.getCoreDataHelper().saveContext()
} catch {
NSLog("Delete request failed")
return
}
}
public static func delete(id: Dictionary<String, Any>) {
delete(predicates: getPredicates(forID: id))
}
// MARK: - Private API
private static func newObject(object: Dictionary<String, Any>) -> NSManagedObjectProtocol {
let entityName = String(describing: self)
let context = CoreDataHelper.getContext()
let managedObject = NSEntityDescription.insertNewObject(forEntityName: entityName, into: context) as! NSManagedObjectProtocol
setValue(managedObject: managedObject, object: object)
CoreDataHelper.getCoreDataHelper().saveContext()
return managedObject
}
private static func request(predicates: [NSPredicate] = [], sortDescriptors: [NSSortDescriptor] = []) -> NSFetchRequest<NSFetchRequestResult> {
// Prepare a request
let entityName = String(describing: self)
let classObject: AnyClass! = NSClassFromString(entityName)
let objectType: NSManagedObject.Type = classObject as! NSManagedObject.Type!
let request: NSFetchRequest<NSFetchRequestResult> = objectType.fetchRequest()
// Add predicates
if predicates.count > 0 {
request.predicate = NSCompoundPredicate.init(andPredicateWithSubpredicates: predicates)
}
// Add sortDescriptors
if sortDescriptors.count > 0 {
request.sortDescriptors = sortDescriptors
}
return request
}
}
を以下ました
public class Currency: NSManagedObject, NSManagedObjectProtocol, XMLImporterDelegate {
private static let attributes = ["name", "currency", "decimalUnit", "isUsed"]
private static let xmlRecordTag = "CcyNtry"
private static let xmlAttributeTags = ["CcyNm": attributes[0],
"Ccy": attributes[1],
"CcyMnrUnts": attributes[2]]
static func setValue(managedObject: NSManagedObjectProtocol, object: Dictionary<String, Any>) {
let currency = managedObject as! Currency
currency.name = getString(from: object, withKeyValue: attributes[0])
currency.currency = getString(from: object, withKeyValue: attributes[1])
currency.decimalUnit = getInt16(from: object, withKeyValue: attributes[2])
currency.isUsed = getBool(from: object, withKeyValue: attributes[3])
return
}
static func getPredicates(forID id: Dictionary<String, Any>) -> [NSPredicate] {
var predicates: [NSPredicate] = []
predicates.append(NSPredicate.init(format: "%@ = %@", attributes[1], getString(from: id, withKeyValue: attributes[1])))
return predicates
}
func isEqual(object: NSManagedObjectProtocol) -> Bool {
if let object = object as? Currency {
if object.currency == self.currency { return false }
return true
} else {
return false
}
}
static func recordTag() -> String {
return xmlRecordTag
}
static func attribute(byTag tag: String) -> String? {
return xmlAttributeTags[tag]
}
static func getUsed() -> [Any]?{
var predicates: [NSPredicate] = []
predicates.append(NSPredicate.init(format: "%@ = %@", attributes[3], NSNumber(booleanLiteral: false)))
return fetch(predicates: predicates)
}
}
"フェッチ" がNSManagedObjectProtocolトレイトで実装されている最後に、これはCoreDataHelperがどのように見えるかです。
class CoreDataHelper: NSObject {
var context: NSManagedObjectContext!
var model: NSManagedObjectModel!
var coordinator: NSPersistentStoreCoordinator!
var store: NSPersistentStore!
let storeFilename = "Accounting.sqlite"
func setupCoreData() {
self.loadStore()
}
func saveContext() {
if (self.context.hasChanges) {
do {
try context.save()
} catch {
}
}
}
func applicationDocumentDictionary() -> String {
let directory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).last!
NSLog("SQLite Directory : %@", directory)
return directory
}
func applicationStoresDirectory() -> URL {
let storesDirectory = URL.init(fileURLWithPath: self.applicationDocumentDictionary()).appendingPathComponent("Stores")
let fileManager = FileManager.default
if (!fileManager.fileExists(atPath: storesDirectory.path)) {
do {
try fileManager.createDirectory(at: storesDirectory,
withIntermediateDirectories: true,
attributes: nil)
} catch {
}
}
return storesDirectory
}
func storesURL() -> URL {
return self.applicationStoresDirectory().appendingPathComponent(storeFilename)
}
override init() {
super.init()
model = NSManagedObjectModel.mergedModel(from: nil)
coordinator = NSPersistentStoreCoordinator(managedObjectModel: model)
context = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
context.persistentStoreCoordinator = coordinator
}
func loadStore() {
if (store != nil) {
return
} else {
do {
try store = coordinator.addPersistentStore(ofType: NSSQLiteStoreType,
configurationName: nil,
at: self.storesURL(),
options: nil)
} catch {
}
}
}
static func getCoreDataHelper() -> CoreDataHelper {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
return appDelegate.coreDataHelper
}
static func getContext() -> NSManagedObjectContext {
return getCoreDataHelper().context
}
}
Countryクラスにalpha3Codeがあることを知らせてください。
extension Country {
@nonobjc public class func fetchRequest() -> NSFetchRequest<Country> {
return NSFetchRequest<Country>(entityName: "Country");
}
@NSManaged public var englishName: String?
@NSManaged public var frenchName: String?
@NSManaged public var alpha2Code: String?
@NSManaged public var alpha3Code: String?
@NSManaged public var countryNumber: Int16
}
で説明したように、 'Country'エンティティ」と呼ばれる、タイプ' STRING'の属性が含まれていますというよりも、
%@キー（パス）を推奨書式指定子%Kを使用しますalpha3Code "？ – shallowThoughtはい、あります。 Countryクラス定義を追加しました –
[述語ドキュメント]（https://developer.apple.com/）で説明されているように、推奨フォーマット指定子 '％K'を'％@ 'ではなくキー（パス）ライブラリ/コンテンツ/ドキュメンテーション/ココア/概念/述語/記事/ pSyntax.html） – vadian