How We Work Offline

Un recorrido por las distintas soluciones para trabajar cuando no hay conexion y sincronizar datos que hemos implementado, no solo para lidiar con la falta de conectividad sino tambien con la mala conectividad. Desde utilizar Receivers hasta Work Manager, analizando el porque necesitamos este tipo de soluciones para mejorar nuestras apps.

Transcript

1. HOW DO WE WORK OFFLINE JUAN CARLOS GARCÍA SECO
2. ▸ Android Developer ▸ jcgseco@gmail.com ▸ @ikarimeister
3. USE CASE
4. ACCESS CONTROL
5. TICKET SALES ON BOARD
6. WHY OFFLINE?
7. TUNNELS
8. REMOTE PLACES
9. GOOD SIGNAL HIGH SPEED
10. NO CONNECTION
11. GOING OFFLINE
12. BACKEND AS SOURCE OF TRUTH
13. PERSISTING OFFLINE REQUESTS
14. sealed class NetworkError : Errors() data class NoInternetConnection( val request: String, val type: OfflineRequestType ) : Errors() object AlreadyCreated : NetworkError() object BadRequest : NetworkError() object Forbidden : NetworkError()
15. suspend fun createSell(sale : SaleRequestDto) : Either<NetworkError, SaleResponseDto> apiClient.createSell(sale) .mapLeft { it.mapToDomainError() }
16. fun NetworkError.mapToDomainError(): DomainError = when (this) { is NoInternetConnection -> { repository?.save(this.request, this.type) DomainError } AlreadyCreated -> DomainError BadRequest -> DomainError Forbidden -> DomainError }
17. INITIAL DATA LOAD
18. WE NEED SOME DATA TO WORK
19. BE AWARE IF YOU NEED THE DATA FOR YOUR FEATURE
20. DON’T BURN THE BACKEND
21. SYNCHRONIZING
22. ON DEMAND SYNC
23. PERIODIC SYNC
24. fun initSync() { val myIntent = Intent(this, SyncService::class.java) val pendingIntent = PendingIntent.getService(this, 0, myIntent, 0) getSystemService(Context.ALARM_SERVICE) .setRepeating( AlarmManager.RTC_WAKEUP, 0, frequency, pendingIntent) }
25. class SyncService : IntentService(SyncService::class.java.name) { lateinit var repository : OfflineRepository lateinit var salesSync : SalesSyncUseCase lateinit var accessSync : AccessControlSyncUseCase lateinit var refundSync : RefundSyncUseCase override fun onHandleIntent(intent: Intent) { if (hasConnection()) { repository.getAll().map{ offlineRequest -> when(offlineRequest.type){ OfflineRequestType.SALES -> salesSync(offlineRequest.request) OfflineRequestType.REFUND -> refundSync(offlineRequest.request) OfflineRequestType.ACCESS_CONTROL -> accessSync(offlineRequest.request) } } } } }
26. IMPROVING UX
27. OFFLINE MODE
28. i apiClient.createSell(sale) .mapLeft { it.mapToDomainError() }
29. LOCAL STORAGE AS SOURCE OF TRUTH
30. REMOVING PROGRESS BAR
31. OPTIMISTIC FEEDBACK
32. JETPACK TO RESCUE
33. WORK MANAGER
34. class RemoveLocalCopy( context: Context, params: WorkerParameters ) : Worker(context, params) { private val use case = UseCase() override fun doWork(): Result = usecase(inputData.keyValueMap[PARAM] as String).fold( { when (it) { IOError -> Result.retry() ForbiddenOperationError, FatalError, ResourceNotFound -> Result.failure() } }, { Result.success(workDataOf(PARAM to it)) } ) }
35. CONSTRAINTS & BACKOFF POLICIES
36. fun OneTimeWorkRequest.Builder.requireInternetWork(data: Data, retry: Long) : OneTimeWorkRequest = this.setConstraints( Constraints.Builder() .setRequiredNetworkType(NetworkType.CONNECTED) .build() ) .setBackoffCriteria(BackoffPolicy.LINEAR, retry, TimeUnit.SECONDS) .setInputData(data) .build()
37. UNIQUE WORKS & EXISTING POLICIES
38. val work: WorkContinuation = WorkManager.getInstance() .beginUniqueWork(uniqueName, ExistingWorkPolicy.KEEP, request1) .then(request2) .then(request3) .then(listOf(request4, request5)) work.enqueue()
39. NEXT STEPS
40. PERIODIC SYNC TO WORKERS
41. OPTIMIZE DATA LOADS
42. THANKS! ANY QUESTIONS? You can find me at: ▸jcgseco@gmail.com ▸@ikarimeister
43. CREDITS AND RESOURCES ▸ Saúl Díaz: Offline Second ▸ Android Dev Podcast: Offline First ▸ Android Dev Podcast: Workers & Room ▸ Android Developers: https://developer.android.com/topic/ libraries/architecture/workmanager ▸ Working with WorkManager (Android Dev Summit ’18): https://www.youtube.com/watch?v=83a4rYXsDs0
44. IMAGES ▸ Barrier Photo: https://www.flickr.com/photos/48603151@N00/ ▸ Box-Office Photos: https://www.flickr.com/photos/incinema/ ▸ Train Photos: https://www.flickr.com/photos/jtcurses9/ ▸ Vader Photo: https://www.flickr.com/photos/jdhancock/ ▸ Offline Photo: https://www.flickr.com/photos/no-luogo/