TCAでViewStoreにKeyPath DynamicMemberLookupが使われてる件

iOSアプリ開発のためのFunctional Architecture情報共有会2 の発表資料です。
https://connpass.com/event/194239/

Transcript

1. TCAͰViewStoreͷStateʹ
   
   
   KeyPath DynamicMemberLookup͕ɹ
   
   
   ࢖ΘΕͯΔ݅
   @yimajo 2020/11/22 #fa_ios
   iOSΞϓϦ։ൃͷͨΊͷFunctional Architecture৘ใڞ༗ձ2
   

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2. TCA͸KeyPathʹΑΔ
   DynamicMemberLookup࢖ͬͯΜͷ͓΋͢
   Εʔʂ
   
   
   ͜Ε͸͍͍ײ͡ͷ࢖͍ํ΍ʔ
   

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3. ຊ౰ʹͦ͏͔ʁ
   
   
   ඞવੑͷ͋Δ࢖͍ํ͔ʁ
   

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4. ͍΍͍΍͍΍ɺ͍͍Ͱ͠ΐɻ
   
   
   Swift 4͘Β͍͔Βͷ KeyPath ɺ
   
   
   ͦͯ͠ Swift 4.2 ͔Βͷ Dynamic Member Lookupɺ
   
   
   ͜ΕΛ্ख͍͜ͱ૊Έ߹Θͤͨ Swift 5.1 ͔Βͷ
   
   
   Key Path ʹΑΔ Dynamic Member Lookup ΍Μɺ
   
   
   ͜ΕΛ࢖ͬͯΔͱؒ઀తʹͰ΋StateʹܕͰΞΫηε
   Ͱ͖ͯؾ࣋ͪ͑ʔΜ΍ɺͦΕҎ্ͷԿ͕͋Μͷ΍ʔʁ
   

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5. ͜Ε͸ͩΊͩɺௐ΂ͯ
   ߟ͑௚ͯ͠ΈΑ͏͔…
   

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6. ࠓճͷ࿩ͷ֓ཁ
   

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7. ࠓճͷ࿩ͷ֓ཁ
   • TCAͰ͸KeyPathʹΑΔDynamic Member LookupʢҎ߱ KeyPath Member Lookupʣ
   ͕࢖ΘΕ͍ͯΔ
   

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8. ࠓճͷ࿩ͷ֓ཁ
   • TCAͰ͸KeyPathʹΑΔDynamic Member LookupʢҎ߱ KeyPath Member Lookupʣ
   ͕࢖ΘΕ͍ͯΔ
   • SwiftUI.View ͔Β State ͷ஋ΛݟΔͱ͖ͳͲ
   

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9. ࠓճͷ࿩ͷ֓ཁ
   • TCAͰ͸KeyPathʹΑΔDynamic Member LookupʢҎ߱ KeyPath Member Lookupʣ
   ͕࢖ΘΕ͍ͯΔ
   • SwiftUI.View ͔Β State ͷ஋ΛݟΔͱ͖ͳͲ
   • ҙຯ͋Δͷʁ௕ॴ͸͋Δͷʁඞવੑ͸ʁ
   

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10. ࠓճͷ࿩ͷ֓ཁ
    • TCAͰ͸KeyPathʹΑΔDynamic Member LookupʢҎ߱ KeyPath Member Lookupʣ
    ͕࢖ΘΕ͍ͯΔ
    • SwiftUI.View ͔Β State ͷ஋ΛݟΔͱ͖ͳͲ
    • ҙຯ͋Δͷʁ௕ॴ͸͋Δͷʁඞવੑ͸ʁ
    • ͜Ε͸ SwiftUI.View ͚ͩݟͯΔͱҙຯ΍ඞવੑ͸෼͔ΓͮΒ͍͔΋
    

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11. ࠓճͷ࿩ͷ֓ཁ
    • TCAͰ͸KeyPathʹΑΔDynamic Member LookupʢҎ߱ KeyPath Member Lookupʣ
    ͕࢖ΘΕ͍ͯΔ
    • SwiftUI.View ͔Β State ͷ஋ΛݟΔͱ͖ͳͲ
    • ҙຯ͋Δͷʁ௕ॴ͸͋Δͷʁඞવੑ͸ʁ
    • ͜Ε͸ SwiftUI.View ͚ͩݟͯΔͱҙຯ΍ඞવੑ͸෼͔ΓͮΒ͍͔΋
    • TCAͰͳ͍ઃܭ΋ҰԠৼΓฦΔ
    

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12. ࠓճͷ࿩ͷ֓ཁ
    • TCAͰ͸KeyPathʹΑΔDynamic Member LookupʢҎ߱ KeyPath Member Lookupʣ
    ͕࢖ΘΕ͍ͯΔ
    • SwiftUI.View ͔Β State ͷ஋ΛݟΔͱ͖ͳͲ
    • ҙຯ͋Δͷʁ௕ॴ͸͋Δͷʁඞવੑ͸ʁ
    • ͜Ε͸ SwiftUI.View ͚ͩݟͯΔͱҙຯ΍ඞવੑ͸෼͔ΓͮΒ͍͔΋
    • TCAͰͳ͍ઃܭ΋ҰԠৼΓฦΔ
    • UIKit ͔Β࢖͏৔߹Λ஌ͬͯΔͱඞવੑ͕͋ΔΑ͏ʹࢥ͑Δ
    

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13. ۩ମྫ
    

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14. TCA ͷ SwiftUI Χ΢ϯλʔαϯϓϧ
    

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15. TCA ͷ SwiftUI Χ΢ϯλʔαϯϓϧ
    

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16. TCA ͷ SwiftUI Χ΢ϯλʔαϯϓϧ
    • SwiftUI͕storeΛอ࣋
    

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17. TCA ͷ SwiftUI Χ΢ϯλʔαϯϓϧ
    • SwiftUI͕storeΛอ࣋
    • store͔ΒviewStoreม਺औΓग़͠
    

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18. TCA ͷ SwiftUI Χ΢ϯλʔαϯϓϧ
    • SwiftUI͕storeΛอ࣋
    • store͔ΒviewStoreม਺औΓग़͠
    • viewStoreܦ༝ͰcountʹΞΫηε
    

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19. 4XJGU6*7JFX
    4UPSF4UBUF "DUJPO
    4UBUF
    ViewStore
    

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20. bow-swift/bow-arch
    ൺֱͱͯ͠
    

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21. bow-swift/bow-arch
    ൺֱͱͯ͠
    

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22. bow-swift/bow-arch
    • SwiftUI.View͕stateͱhandleΛอ࣋
    ൺֱͱͯ͠
    

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23. bow-swift/bow-arch
    • SwiftUI.View͕stateͱhandleΛอ࣋
    • handle͕Stateͷૢ࡞
    ൺֱͱͯ͠
    

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24. bow-swift/bow-arch
    • SwiftUI.View͕stateͱhandleΛอ࣋
    • handle͕Stateͷૢ࡞
    • ͍ΘΏΔReducer
    ൺֱͱͯ͠
    

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25. 4XJGU6*7JFX
    4UBUF )BOEMF
    

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26. ࣮ࡍ
    
    
    TCA Ͱ KeyPath Member Lookup
    
    
    ͨ͘͠ͳΔؾ࣋ͪ΋෼͔Δ͕
    
    
    ͳͯ͘΋ྑ͍ؾ΋͢Δ
    

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27. UIKitͰͷTCAͷ࢖͍ํΛݟͯΈΔ
    

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28. TCAͰUIKitͰͷ
    
    
    Χ΢ϯλʔαϯϓϧ
    … লུ
    

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29. TCAͰUIKitͰͷ
    
    
    Χ΢ϯλʔαϯϓϧ
    … লུ
    

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30. TCAͰUIKitͰͷ
    
    
    Χ΢ϯλʔαϯϓϧ
    • viewStore.publisher Ͱ $0.count
    … লུ
    

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31. TCAͰUIKitͰͷ
    
    
    Χ΢ϯλʔαϯϓϧ
    • viewStore.publisher Ͱ $0.count
    • ͦͷ஋ΛUITextLabelͷtextʹ
    … লུ
    

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32. TCAͰUIKitͰͷ
    
    
    Χ΢ϯλʔαϯϓϧ
    • viewStore.publisher Ͱ $0.count
    • ͦͷ஋ΛUITextLabelͷtextʹ
    … লུ
    ͭ·Γ
    
    
    State ͕ Publisher ͰऔಘͰ͖Δ
    

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33. ViewStoreΈͯΈΔ
    

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34. ViewStoreΈͯΈΔ
    • publisher:
    StorePublisher
    

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35. ViewStoreΈͯΈΔ
    • publisher:
    StorePublisher
    StorePublisher Λ
    
    
    ͞Βʹৄ͘͠஌Γ͍ͨ
    

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36. StorePublisherΈͯΈΔ
    

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37. StorePublisherΈͯΈΔ
    • StorePublisher͸Publisherʹ४ڌͯ͠
    ͍ΔͷͰStateΛετϦʔϜʹྲྀͤΔ
    

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38. StorePublisherΈͯΈΔ
    • StorePublisher͸Publisherʹ४ڌͯ͠
    ͍ΔͷͰStateΛετϦʔϜʹྲྀͤΔ
    

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39. StorePublisherΈͯΈΔ
    • StorePublisher͸Publisherʹ४ڌͯ͠
    ͍ΔͷͰStateΛετϦʔϜʹྲྀͤΔ
    • ͞Βʹ subscript Ͱmapͯ͠Δ
    

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40. StorePublisherΈͯΈΔ
    • StorePublisher͸Publisherʹ४ڌͯ͠
    ͍ΔͷͰStateΛετϦʔϜʹྲྀͤΔ
    • ͞Βʹ subscript Ͱmapͯ͠Δ
    ͭ·ΓɺStorePublisherʹରͯ͠΋
    KeyPath Member Lookup ͯ͠ map
    ͠ Publisher Λฦͯ͠Δ
    

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41. →
    self.viewStore.publisher.count
    
    
    .assign(to: \.text, on: countLabel)
    
    
    .store(in: &self.cancellables)
    ͭ·Γ …
    

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42. →
    self.viewStore.publisher.count
    
    
    .assign(to: \.text, on: countLabel)
    
    
    .store(in: &self.cancellables)
    ࠨͷΑ͏ʹࣗલͰ .publisher ʹ .map Λॻ͔ͳ͍͍ͯ͘ʂ
    ͭ·Γ …
    

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43. →
    self.viewStore.publisher.count
    
    
    .assign(to: \.text, on: countLabel)
    
    
    .store(in: &self.cancellables)
    ࠨͷΑ͏ʹࣗલͰ .publisher ʹ .map Λॻ͔ͳ͍͍ͯ͘ʂ
    KeyPath Member Lookup ࢖ͬͯলུͰ͖Δʢӈʣɻ
    ͭ·Γ …
    

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44. View Slide

45. \\\ ετϦʔϜΛѻ͏ͱ͖ State ͱ͍͏ม਺͸ݟ͑ͳͯ͘ྑͦ͞͏ ///
    

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46. ↓
    \\\ ετϦʔϜΛѻ͏ͱ͖ State ͱ͍͏ม਺͸ݟ͑ͳͯ͘ྑͦ͞͏ ///
    

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47. ↓
    ετϦʔϜΛѻΘͣ State ͷϓϩύςΟ͕ཉ͍͠ͱ͖΋ɺ
    \\\ ετϦʔϜΛѻ͏ͱ͖ State ͱ͍͏ม਺͸ݟ͑ͳͯ͘ྑͦ͞͏ ///
    

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48. ↓
    ετϦʔϜΛѻΘͣ State ͷϓϩύςΟ͕ཉ͍͠ͱ͖΋ɺ
    State ͱ͍͏ม਺͸ݟ͑ͳ͍΄͏͕ରশੑ͕͋Δ…͔΋…
    \\\ ετϦʔϜΛѻ͏ͱ͖ State ͱ͍͏ม਺͸ݟ͑ͳͯ͘ྑͦ͞͏ ///
    

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49. 7JFX4UPSF
    4UBUF
    viewStore.count ͍ͩ͘͞
    state.count: Int ฦ͢
    viewStore.publisher.count ͍ͩ͘͞
    StorePublisher͔Β
    
    
    StorePublisherͳ count ฦ͢
    ϓϩύςΟͷ
    ஋͕ཉ͍͠
    1VCMJTIFSΛ
    TJOLͯ͠
    Ͳ͏ʹ͔͍ͨ͠
    

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50. ͓ΘΓʹ: ٞ࿦ͷϙΠϯτ
    • KeyPath Member Lookup ͳͯ͘΋ྑ͍ͱ͸ࢥ͏͚Ͳ΋
    
    
    • Publisherͱͯ͠ཉ͍͠৔߹ͷΠϯλϑΣʔεͰ͸৑௕͞Λল͚ͯΔ
    
    
    • StateͷϓϩύςΟ͕΄͍͠ͱ͖΋ɺKeyPath Member LookupΛ
    ࢖ͬͨ΄͏͕ରশੑ΍౷Ұײ͕͋Δͷ͸෼͔Δ
    

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