΍΍complexͳBLoC΁ͷରԠ Hiroki Matsue Jan 30th, 2019 Flutter Meetup Tokyo #7

Hiroki Matsue (@macs_6)

IIJmio޲͚ʮΈ͓εΠονʯ (Flutter੡)

analysis͸࢝Ίʹઃఆ͠Α͏ omit_local_variable_types༗ޮʹ͠·͠ΐ͏ https://www.dartlang.org/guides/language/effective-dart/design#avoid-type-annotating- initialized-local-variables

લճ͸Dart೉ಡԽͷ࿩

ࠓճ͸BLoCͷ࿩

BLoCͷ͓͞Β͍

Business Logic Componentsύλʔϯ

Google I/O '18: https://www.youtube.com/watch? v=RS36gBEp8OI

Google I/O '18: https://www.youtube.com/watch? v=RS36gBEp8OI

Google I/O '18: https://www.youtube.com/watch? v=RS36gBEp8OI

ϓϩτλΠϓҎ߱ͷϑΣʔζ͸ɺBLoC ΍Reduxಋೖ͓ͯ͘͠ͱ҆৺

ը໘1ͭʹBLoC1ͭͷγϯϓϧͳ ঢ়ଶ؅ཧͷ৔߹

buttonͦΕͧΕʹLoading΍ErrorΛ දݱ͍ͨ͠ (ΞΠςϜҰཡ͔Β1ͭΛ͓ؾʹೖΓɺΧʔυʹೖΕΔɺetc)

͜Μͳ࣌

αϯϓϧ࣮૷Ͱͷ૝ఆσʔλߏ଄ - ܖ໿1 - sim1 - sim2 - ... - ܖ໿2 - ... - ...

·ͣܖ໿ͱSIM2ͭͷBLoCΛܨ͙ You should avoid having one BLoC as a parameter of another BLoC. Instead, plug only the required outputs to the applicable inputs. This helps avoid tight coupling. https://medium.com/flutter-io/build-reactive-mobile-apps-in-flutter-companion- article-13950959e381 _bloc = SimBloc(widget.sim); // ܖ໿BLoCͷstreamΛSIMBLoC͕listen _subscription = widget.simsStream.listen(_bloc.sims.add);

ܨ͍ͩΒ2ͭ໨ͷBLoC಺ʹࢦఆͨ͠ SIMΛॲཧ͢ΔϩδοΫΛॻ͘

class SimBloc { SimBloc(Sim sim) { _simController.stream .map((list) => list.firstWhere((s) => s == sim, orElse: () => null)) .listen((sim) { if (sim == null) { log(errorMessage); // print log and send error to Sentry return; } _simSubject.add(SimState( switchingStatus: SimSwitchingStatus.fulfilled, isEnabled: sim.isEnabled, usage: sim.inMonthUsage(), )); ...

ࢀߟ: filiph/state_experiments@github (ಛʹbloc_complexपΓ)

BLoCಋೖͯ͠ྑ͔ͬͨ͜ͱ • ϘλϯͷΑ͏ͳ୯ҐͰͷঢ়ଶΛ؅ཧ͠΍͘͢ͳͬͨ • ςετ͕ॻ͖΍͘͢ͳͬͨ

Έ͓εΠονɺੋඇ͝ར༻͍ͩ͘͞

Thanks