SwiftData All In One

https://developer.apple.com/documentation/swiftdata

`@Model` 注解修饰器


import SwiftUI
import SwiftData

@Model
class RemoteImage {
  var sourceURL: URL
  var data: Data
  
  init(sourceURL: URL, data: Data = Data()) {
    self.sourceURL = sourceURL
    self.data = data
  }
}

expand marco


import SwiftUI
import SwiftData

@Model
class RemoteImage {
  @_PersistedProperty
  var sourceURL: URL
  @_PersistedProperty
  var data: Data
  
  init(sourceURL: URL, data: Data = Data()) {
    self.sourceURL = sourceURL
    self.data = data
  }
  @Transient
  private var _$backingData: any SwiftData.BackingData<RemoteImage> = RemoteImage.createBackingData()

  public var persistentBackingData: any SwiftData.BackingData<RemoteImage> {
    get {
      return _$backingData
    }
    set {
      _$backingData = newValue
    }
  }

  static var schemaMetadata: [SwiftData.Schema.PropertyMetadata] {
    return [
      SwiftData.Schema.PropertyMetadata(name: "sourceURL", keypath: \RemoteImage.sourceURL, defaultValue: nil, metadata: nil),
      SwiftData.Schema.PropertyMetadata(name: "data", keypath: \RemoteImage.data, defaultValue: nil, metadata: nil)
    ]
  }

  required init(backingData: any SwiftData.BackingData<RemoteImage>) {
    _sourceURL = _SwiftDataNoType()
    _data = _SwiftDataNoType()
    self.persistentBackingData = backingData
  }

  @Transient private let _$observationRegistrar = Observation.ObservationRegistrar()

  internal nonisolated func access<_M>(
    keyPath: KeyPath<RemoteImage, _M>
  ) {
    _$observationRegistrar.access(self, keyPath: keyPath)
  }

  internal nonisolated func withMutation<_M, _MR>(
    keyPath: KeyPath<RemoteImage, _M>,
    _ mutation: () throws -> _MR
  ) rethrows -> _MR {
    try _$observationRegistrar.withMutation(of: self, keyPath: keyPath, mutation)
  }

  struct _SwiftDataNoType {
  }
}
extension RemoteImage: SwiftData.PersistentModel {
}

extension RemoteImage: Observation.Observable {
}

https://developer.apple.com/documentation/swiftdata/model()

https://developer.apple.com/documentation/swiftdata/persistentmodel

Core Data

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

.xcdatamodeld

https://developer.apple.com/documentation/coredata/creating-a-core-data-model

`SwiftData` vs `Core Data`

SwiftData 新版
Core Data 旧版
混合版，保留 Core Data + 渐进式 SwiftData

https://developer.apple.com/documentation/CoreData/adopting-swiftdata-for-a-core-data-app

https://developer.apple.com/documentation/coredata/core-data-model

demos

@attached(member, conformances: Observable, PersistentModel, Sendable, names: named(_\(backingData), named(persistentBackingData), named(schemaMetadata), named(init), named(_\)observationRegistrar), named(_SwiftDataNoType), named(access), named(withMutation)) @attached(memberAttribute) @attached(extension, conformances: Observable, PersistentModel, Sendable) macro Model()

// provide conformance to the PersistentModel and Observable protocols.

@Model
class RemoteImage {
    var sourceURL: URL
    var data: Data

    init(sourceURL: URL, data: Data = Data()) {
        self.sourceURL = sourceURL
        self.data = data
    }
}

import SwiftData

// Annotate new or existing model classes with the @Model macro.
@Model
class Trip {
    var name: String
    var destination: String
    var startDate: Date
    var endDate: Date
    var accommodation: Accommodation?
}

https://developer.apple.com/documentation/swiftdata/preserving-your-apps-model-data-across-launches