ReactiveCocoa Pitfalls at freee

Transcript

1. ReactiveCocoa Pitfalls at freee @yonekawa

2. freeeͷiOSΞϓϦ͕ ReactiveCocoaΛಋೖ͔ͯ͠ Β̕ϲ݄͕ܦͪ·ͨ͠

3. • 2014/12/20 iOSΞϓϦ։ൃணख • 2014/01/10 ReactiveCocoaಋೖ • 2014/02/14 1.0.0ϦϦʔε

4. ೥຤ʹҰମԿ͕ɾɾɾ

5. ReactiveCocoaΛ࢖͍ͬͯͯ freeeͰى͖ͨ໰୊΍ ϋϚΓͲ͜ΖΛ঺հ͠·͢ ஫: ReactiveCocoaͷAPI͕ͪΐ͍ͪΐ͍ग़͖ͯ·͢

6. combineLatestWith

7. combineLatestWithͱSignalͷ࣮ߦॱ • combineLatestWith͸ฒྻʹSignalΛ࣮ߦ͢Δ ͷͰൃՐ͞ΕΔॱং͸ෆఆɻϩάΠϯ͔ͯ͠Βσʔ λΛऔಘɺΈ͍ͨͳॲཧʹ࢖͏ͱϋϚΔ • ௚ྻʹ͍ͨ࣌͠ʹ͸flattenMapΛ࢖͏

8. rac_textSignal

9. rac_textSignal vs RACObserve • textϓϩύςΟʹ௚઀୅ೖ͢ΔΑ͏ͳέʔεͰγ άφϧ͕ൃՐ͠ͳ͍ɻRACObserveͰtextϓϩύ ςΟΛsubscribe͢ΔͱൃՐ͢Δ • ٯʹΩʔϘʔυ͔Βͷೖྗ͸RACObserveͩͱൃՐ ͠ͳ͍ɻrac_textSignalͰऔΒͳ͍ͱ͍͚ͳ͍

   • combineLatestͯ྆͠ํൃՐ͢ΔsignalΛ࡞ͬ ͨΓͨ͠

10. sendCompleted

11. None

12. sendErrorͷޙͷsendCompleted • sendErrorͷޙʹsendCompletedΛݺΜͰ΋ݺ ͹Εͳ͍ɻ • subscribe͢ΔଆͰnextͱerrorͰڞ௨Ͱ΍Γͨ ͍ॲཧʢΠϯδέʔλΛࢭΊΔͱ͔ʣΛॻ͖͍ͨ࣌ ʹ͸ݸผʹॻ͔ͳ͍ͱ͍͚ͳ͍

13. [RACSignal empty]

14. None

15. [RACSignal empty] • RACSignalϕʔεͰ΍ΓऔΓ͍ͯ͠Δ࣌ɺ [RACSignal empty]Λฦ͢ͱ౰વnext΋error΋ൃ Ր͞Εͳ͍ • subscribeલʹΠϯδέʔλΛճͯ͠nextͱerrorͰ ࢭΊ͍ͯΔ৔߹ɺΠϯδέʔλ͕ճΓͬͺͳ͠ʹͳΔ

    • empty͡Όͳۭͯ͘ͷ݁ՌΛฦ͢SignalΛฦ͢ͷ͕Α ͦ͞͏

16. UITableView

17. Cellͷதʹsubscribe͍ͨ͠View͕͋Δ࣌ • ηϧ͕࠶ར༻͞ΕΔͱೋॏʹϑΥʔ ϜͷΠϕϯτΛsubscribeͯ͠ ͠·͏ • reloadͳͲߟ͑Δͱ subscriberΛഁغ͢ΔλΠϛϯ ά͕೉͍͠ •

    ݱঢ়͸ۤ೑ͷࡦͰ࠶ར༻΍ΊͨΓ ͯ͠Δ

18. ReactiveCocoa3.0

19. ReactiveCocoa3.0 • LTͷͨΊʹແ஡ͯ͠ಋೖ͠Α͏ͱௐ΂ͨ • طଘͷRACSignalϕʔεͷΠϯλϑΣʔεΛ asColdSignalͱ͔Ͱ͖Δͷ͸ָͦ͏ͩͬͨ • υΩϡϝϯτແ͠Ͱ࢖͍ํΛ୳Δͷ௒೉͍͠