AndroidXとKotlin Coroutines

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!