iOS封装CoreData+HandyJson实现本地缓存
准备工作
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选中Tagets->BuildPhases->LinkBinaryWithLibraries 添加CoreData.framework
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使用CocoaPods工具Pod需要使用的相关框架
pod 'AlecrimCoreData'
pod 'HandyJSON', '~> 5.0.1'
CoreData基本使用查看上篇博客《CoreData数据持久化》
链接如下：
配置 PersistentContainer
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创建PersistentContainer+App.swift
-
代码如下
import Foundation
import AlecrimCoreData
extension PersistentContainer {
public convenience init(name: String? = nil, bundle: Bundle? = nil) {
try! self.init(name: name,
managedObjectModel: type(of: self).managedObjectModel(withName: name,
in: bundle ?? Bundle.main),
storageType: .disk,
persistentStoreURL: try! type(of: self).persistentStoreURL(withName: name, inPath: ""),
persistentStoreDescriptionOptions: nil,
ubiquitousConfiguration: nil)
}
}
创建 StorageService.swift
代码如下
import Foundation
import AlecrimCoreData
import CoreData
import HandyJSON
public final class StorageService: NSObject {
@objc public static let shared = StorageService()
private override init() {}
private lazy var container = PersistentContainer(name: "DataModel", bundle: nil)
}
extension NSManagedObjectContext {
fileprivate var dataModel: Query<DataModel> { return Query(in: self) }
}
extension StorageService {
public func set<T>(_ value: T, forKey defaultName: String) {
let v: String = {
switch value {
case let value as String:
return value
case let value as Int:
return String(value)
case let value as Float:
return String(value)
case let value as Double:
return String(value)
case let value as Bool:
return String(value)
case let value as URL:
return value.absoluteString
default:
fatalError("无效的类型")
}
}()
container.performBackgroundTask { context in
let query = context.dataModel.where { \.key == defaultName }
if let model = query.first() {
model.value = v
} else {
let model = DataModel(context: context)
model.key = defaultName
model.value = v
}
if context.hasChanges {
try? context.save()
}
}
}
private func _get(forKey defaultName: String) -> String? {
// 步骤一：获取总代理和托管对象总管
let context = container.viewContext
// 步骤二：建立一个获取的请求
let query = context.dataModel.where { \.key == defaultName }
if let result = query.first() {
return result.value
}
return nil
}
@objc public func remove(forKey defaultName: String) {
container.performBackgroundTask { context in
let fetchRequest: NSFetchRequest<DataModel> = DataModel.fetchRequest()
fetchRequest.predicate = NSPredicate(format: "key==%@", defaultName)
if let results = try? context.fetch(fetchRequest) {
for result in results {
context.delete(result)
}
if context.hasChanges {
try? context.save()
}
}
}
}
// MARK: - 普通类型
@objc public func isExist(forKey defaultName: String) -> Bool {
return _get(forKey: defaultName) != nil
}
@objc public func integer(forKey defaultName: String) -> Int {
let value = _get(forKey: defaultName)
return Int(value ?? "0") ?? 0
}
@objc public func float(forKey defaultName: String) -> Float {
let value = _get(forKey: defaultName)
return Float(value ?? "0") ?? 0
}
@objc public func double(forKey defaultName: String) -> Double {
let value = _get(forKey: defaultName)
return Double(value ?? "0") ?? 0
}
@objc public func string(forKey defaultName: String) -> String {
let value = _get(forKey: defaultName)
return value ?? ""
}
@objc public func bool(forKey defaultName: String) -> Bool {
let value = _get(forKey: defaultName)
return Bool(value ?? "") ?? false
}
@objc public func url(forKey defaultName: String) -> URL? {
let value = _get(forKey: defaultName)
return URL(string: value ?? "")
}
}
// MARK: - HandyJSON
extension StorageService {
public func set<T>(_ value: T, forKey defaultName: String) where T: HandyJSON {
set(value.toJSONString()!, forKey: defaultName)
}
public func model<T>(forKey defaultName: String) -> T where T: HandyJSON {
let text: String = _get(forKey: defaultName) ?? ""
return T.deserialize(from: text) ?? T()
}
public func set<T>(_ value: [T], forKey defaultName: String) where T: HandyJSON {
set(value.toJSONString()!, forKey: defaultName)
}
public func models<T>(forKey defaultName: String) -> [T] where T: HandyJSON {
let text: String = _get(forKey: defaultName) ?? ""
return ([T].deserialize(from: text) ?? []) as! [T]
}
}
// MARK: - 仅用于OC
extension StorageService {
@available(*, deprecated, message: "仅用于OC")
@objc public func setString(_ value: String, forKey defaultName: String) {
set(value, forKey: defaultName)
}
}
总结
-
利用AlecrimCoreData实现CoreData配置简易化
-
HandyJson作为中介者，存储到本地的为JsonString字符串，Json字符串与Model或者Models的转换
Roder, 我的博客
