SwiftData: Dive into inheritance and schema migration - Swift愛好会スピンオフ WWDC25セッション要約会

1. ू·ΕSwift޷͖ʂSwiftѪ޷ձεϐϯΦϑ WWDC25ηογϣϯཁ໿ձ SwiftData: Dive into inheritance and schema migration ͍·͑͢, X: 1mash0_
2. Topics Harness class inheritance Evolving data with migration Tailoring fetched data Observing changes to data
3. Harness class inheritance iOS 26͔ΒSwiftDataϞσϧͷΫϥεܧঝ͕αϙʔτ͞Εͨ ܧঝΛ༻͍Δ͜ͱͰɺαϒΫϥε͸਌ΫϥεͷϓϩύςΟ΍ৼΔ෣͍ΛҾ͖ܧ͙͜ͱ ͕Ͱ͖Δ @Model class Trip { ... } @available(iOS 26, *) @Model class BusinessTrip: Trip { var perdiem: Double = 0.0 } @available(iOS 26, *) @Model class PersonalTrip: Trip { var reason: Reason }
4. Harness class inheritance ࢖͍ํ͸ෳ਺ͷϞσϧΛѻ͍͍ͨ࣌ͱಉ͡Α͏ʹ౉͚ͩ͢ WindowGroup { ContentView() } .modelContainer(for: [Trip.self, PersonalTrip.self, BusinessTrip.self]) let modelContainer = try ModelContainer( for: Trip.self, PersonalTrip.self, BusinessTrip.self ) WindowGroup { ContentView() } .modelContainer(modelContainer)
5. Harness class inheritance ϙΠϯτ ਌ΫϥεͱαϒΫϥε͕֊૚ߏ଄Λ࣋ͭ͜ͱ is-a ͷؔ܎͕੒Γཱͭ͜ͱ ֊૚ߏ଄Λ࣋ͨͣɺ୯ҰϓϩύςΟͷڞ༗͕໨తͷ৔߹͸ϓϩτίϧ४ڌʹ͢Δ σΟʔϓαʔνͱγϟϩʔαʔνͷ྆ํΛར༻͢Δ͜ͱ σΟʔϓαʔνͷΈͷ৔߹͸ɺ਌ΫϥεͷϓϩύςΟͱݟͳ͢΂͖ γϟϩʔαʔνͷΈͷ৔߹͸ɺͦΕͧΕͰϞσϧΛ࡞੒͢Δ΂͖
6. Evolving data with migration VersionedSchemaͱSchemaMigrationPlanΛ༻͍ͯɺաڈόʔδϣϯ͔Βͷ ϚΠάϨʔγϣϯ͕Մೳ iOS 17: εΩʔϚόʔδϣϯ2.0 SwiftData͕ಋೖ iOS 18: εΩʔϚόʔδϣϯ3.0 ॏෳσʔλΛղফ͢ΔͨΊʹΧελϜͷMigrationStageΛ࢖༻ iOS 26: εΩʔϚόʔδϣϯ4.0 αϒΫϥεΛ௥Ճ ηογϣϯதͩͱMigrationStage.lightweightͰϚΠάϨʔγϣϯ͕ߦΘ ΕͯΔ
7. Tailoring fetched data SampleTripsΞϓϦʹݕࡧόʔͰͷݕࡧػೳ͕࠶ಋೖ ηάϝϯτͱݕࡧςΩετͷPredicateΛ૊Έ߹ΘͤͯϑΟϧλϦϯά͍ͯ͠Δ αϒΫϥεʹߜͬͯϑΟϧλϦϯά͢ΔPredicateͷੜ੒ let predicate: Predicate<Trip>? = #Predicate { $0 is PersonalTrip }
8. Tailoring fetched data ϚΠάϨʔγϣϯ࣌ͷϑΣονॲཧύϑΥʔϚϯε޲্ͷ࿩ propertiesToFetchΛ࢖༻ͯ͠ඞཁͳϓϩύςΟͷσʔλ͚ͩΛ࣋ͬͨϞσϧΛ औಘ͢ΔΑ͏࠷దԽ ಛఆͷϦϨʔγϣϯγοϓΛḷΔඞཁ͕͋Δ৔߹ relationshipKeyPathsForPrefetchingΛ࢖ͬͯ࠷దԽΛਤΕΔ SampleTripsΞϓϦͷ΢ΟδΣοτͰ͸࠷৽ͷ1݅ͷΈ͕ඞཁͳͨΊɺfetchLimit Λઃఆͯ͠ޮ཰ΛߴΊ͍ͯΔ
9. Observing changes to data PersistentModel͸Observable withObservationTrackingΛ࢖͏͜ͱͰϞσϧͷϓϩύςΟʹՃ͑ΒΕͨมߋΛ ؂ࢹͰ͖Δ ͨͩ͠؍ଌͰ͖Δͷ͸ಉҰͷϓϩηε಺ͰߦΘΕͨมߋͷΈ ΢ΟδΣοτɺΤΫεςϯγϣϯɺΞϓϦ಺ͷผModelContainer͔ΒՃ͑ΒΕͨ มߋ͸؍ଌͰ͖ͳ͍
10. Observing changes to data ಉҰModelContainerͰɺผModelContextͰ͋ͬͯ΋QueryΛ࢖༻͍ͯ͠Δ৔ ߹͸มߋ͕ࣗಈͰ൓ө͞ΕΔ ϑΣονAPIͳͲΛར༻͍ͯ͠Δ৔߹ɺผModelContextͰՃ͑ΒΕͨมߋ͸࠶ϑΣο ν͠ͳ͍ͱ൓ө͞Εͳ͍ ࠶ϑΣον͸ίετ͕ߴ͍ͨΊɺཤྺػೳΛར༻ͯ͠࠶ϑΣον͕ඞཁ͔Ͳ͏͔Λ൑அ ͢ΔΑ͏ʹ͢Δ
11. Observing changes to data iOS 26͔ΒཤྺΛsortByͰฒ΂ସ͑ͯऔಘͰ͖ΔΑ͏ʹͳͬͨ ࠓ·Ͱ͸ཤྺΛશ݅औಘͯ͠͠·͏Մೳੑ͕͕͋ͬͨɺޮ཰తʹ࠷৽ͷཤྺτʔΫϯΛ औಘͰ͖ΔΑ͏ʹͳͬͨ var historyDesc = HistoryDescriptor<DefaultHistoryTransaction>() historyDesc.sortBy = [.init(\.transactionIdentifier, order: .reverse)] historyDesc.fetchLimit = 1 let transactions = try context.fetchHistory(historyDesc)