Kotlin Multiplatform

Transcript

1. Kotlin Multiplatform 集まれもうやんカレーとKotlin好き！Kotlin愛好会 vol6

2. About Me • Matthew Vern / Panini • Twitter: @callipan

   Github: panpanini • Mercari, Inc • Android Engineer (US) • Kotlin可愛い

3. Summary • I made a Kotlin Multiplatform project！ • It

   has an Android and iOS app both backed by a common library

4. Kotlin Multiplatform

5. Kotlin Multiplatform • https://speakerdeck.com/panini/kotlin-multi-platform • This time I will actually

   talk about Kotlin Multiplatform

6. Kotlin Multiplatform • https://kotlinlang.org/docs/reference/multiplatform.html • 1 codebase, multiple platforms ◦

   Android ◦ iOS ◦ JS ◦ (JVM)

7. Kotlin Multiplatform - requirements • Multiplatform code must be 100%

   pure Kotlin • Platform specific code must be referenced using `expect` and `actual`

8. Kotlin Multiplatform - tutorial • https://kotlinlang.org/docs/tutorials/native/mpp-ios-android.html • Explains how to

   use `expect` and `actual` mechanism expect fun platformName(): String fun createApplicationScreenMessage() : String { return "Kotlin Rocks on ${platformName()}" }

9. :thinking:

10. Kotlin Multiplatform - tutorial v2.0 • I want a realistic

    sample project, that reflects real world usage • It should perform network operations • UI should be managed by each platform, so only logic should be shared

11. Lets build!

12. Lets build! • I wrote some details in this blog,

    please check it! • https://tech.mercari.com/entry/2018/12/18/114010 • I want to build this architecture

13. Lets build! • First, lets build http client • Because

    I’m normally an Android Engineer, lets use Retrofit • https://square.github.io/retrofit/ • It lets us make network calls just by creating an interface
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15. Kotlin Multiplatform - requirements • Multiplatform code must be 100%

    pure Kotlin • Platform specific code must be referenced using `expect` and `actual`
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19. Ktor • https://ktor.io • Kotlin http server • Kotlin http

    client

20. Ktor • https://ktor.io • Kotlin http server • Kotlin http

    client • Multiplatform support

21. Lets build!!!!

22. Service.kt

23. ViewModel.kt

24. Observable.kt

25. Lets build iOS!!!!

26. Observable.kt

27. Observable.kt

28. Lets open Xcode!!!!

29. Xcode………..

30. SplatMaps.xcproject

31. ViewController.swift

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33. Lets build Android!!!!

34. SplatoonCoroutine.idea

35. MatchFragment.kt

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37. Summary • I made a Kotlin Multiplatform project！ • It

    has an Android and iOS app both backed by a common library • Http client is not as easy to use as Retrofit • return KotlinUnit() is ダサイ... • Kotlin works anywhere and that makes it 可愛い • https://github.com/panpanini/SplatMaps-Multiplatform

38. Have a nice Kotlin!