AndroidXとKotlin Coroutines

Transcript

1. AndroidXͱKotlin Corou.nes @takuji31 ؼ͖ͬͯͨؔ੢ϞόΠϧΞϓϦݚڀձ

2. ࣗݾ঺հ

3. ࣗݾ঺հ • @takuji31 id:takuji31 • Takuji Nishibayashi • Hatena Co.,

   Ltd. • App Team • ίϛοΫDAYS • δϟϯϓϧʔΩʔʂ • ΧΫϤϜ

4. ࣗݾ঺հ • Android • Kotlin • Flu-er • ! h-ps:/

   /blog.takuji31.jp • " h-ps:/ /nazuna.takuji31.jp • # $ h-ps:/ /photo.takuji31.jp

5. AndroidX

6. LiveData? ViewModel? AppCompat? Naviga5on

7. ࢖ͬͯ·͢ΑͶ

8. Kotlin Corou+nes

9. ࢖ͬͯ·͔͢ʁ

10. Google I/O 2019

11. Android development will become increasingly Kotlin-first — h$ps://android-developers.googleblog.com/2019/05/google- io-2019-empowering-developers-to-build-experiences-on-Android- Play.html

12. AndroidXʹ΋Kotlinαϙʔτ͕ଓʑ

13. Ұ෦ → h$ps:/ /speakerdeck.com/ takuji31/androidxniqian-mubian-li- nayatura

14. ࠓ೔͸Corou%neαϙʔτͷ࿩Λ͠ ·͢

15. α൛ͷ΋ͷ΋ؚ·ΕΔͷͰ ͝ར༻͸ܭըతʹ

16. ViewModel.viewModelScope

17. ViewModelͷonClearedͰΩϟϯ ηϧ͞ΕΔCoroutineScope

18. ViewModel಺ͰCorou,neΛ࢖͍΍ ͘͢ͳΔ

19. Dispatcher͸ Dispatchers.Main͕ઃఆ͞ΕΔ

20. ໌ࣔతʹࢦఆ͠ͳ͍ݶΓશͯͷॲཧ ͕ϝΠϯεϨουͰ࣮ߦ

21. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

22. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

23. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

24. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

25. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

26. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

27. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

28. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

29. class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }

30. ※DispatcherΛઃఆ͠ͳ͍··ॏ͍ ॲཧΛ͠ͳ͍

31. LifecycleOwner .lifecycleScope

32. Lifecycleͱ࿈ಈͨ͠ CoroutineScope

33. Lifecycle.State.DESTROYED ʹͳͬͨ࣌ʹΩϟϯηϧ͞ΕΔ CoroutineScope

34. whenCreated / whenStarted / whenResumed

35. fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }

36. fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }

37. fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }

38. fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }

39. fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }

40. liveData()

41. Corou%neΛLiveDataʹม׵

42. class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }

43. class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }

44. class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }

45. class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }

46. class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }

47. Ҿ਺ͷblock͕suspended func.on

48. LiveData͕Ac*veʹͳͬͨ࣌ʹblock ͷॲཧ͕࣮ߦ͞ΕΔ

49. ྫ֎͕ൃੜͨ͠ΒͦΕҎ߱͸஋͕ྲྀ Εͳ͍

50. ͦͷଞ

51. ͦͷଞ • CoroutineWorker • Work ManagerͷWorkerͷdoWork͕suspended func2onͳόʔδϣϯ • όοΫάϥ΢ϯυͰඇಉظॲཧΛ͍ͨ࣌͠ʹ࢖͑ͦ͏ •

    room-ktx • RoomͷDAOͷϝιουʹsuspended func2on͕࢖͑Δ • @Transac2onͱ஫ऍͨ͠ϝιουΛݺͿͱੜ੒͞ΕΔDAOͷϝιου ͕τϥϯβΫγϣϯͰ·ͱΊΒΕΔ

52. h"ps:/ /developer.android.com/ topic/libraries/architecture/ corou6nes

53. Enjoy Kotlin Corou.nes life!