Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Kotlin Flow
Search
José Caique Oliveira
June 21, 2019
Programming
0
110
Kotlin Flow
An early look at Kotlin Flow
José Caique Oliveira
June 21, 2019
Tweet
Share
More Decks by José Caique Oliveira
See All by José Caique Oliveira
Coroutines And Flow
jcaiqueoliveira
2
110
Testing your app
jcaiqueoliveira
0
290
Modularizando seu app
jcaiqueoliveira
0
71
Nova Api de Localização Android
jcaiqueoliveira
0
83
Arquitetura para android
jcaiqueoliveira
6
320
Kotlin por onde começar?
jcaiqueoliveira
1
90
Introdução ao Android
jcaiqueoliveira
1
81
Arquitetura para projetos Android
jcaiqueoliveira
1
230
Kotlin 1.1
jcaiqueoliveira
0
130
Other Decks in Programming
See All in Programming
はじめてのMaterial3 Expressive
ym223
2
890
知っているようで知らない"rails new"の世界 / The World of "rails new" You Think You Know but Don't
luccafort
PRO
1
180
1から理解するWeb Push
dora1998
7
1.9k
Improving my own Ruby thereafter
sisshiki1969
1
160
FindyにおけるTakumi活用と脆弱性管理のこれから
rvirus0817
0
530
Rancher と Terraform
fufuhu
2
550
請來的 AI Agent 同事們在寫程式時,怎麼用 pytest 去除各種幻想與盲點
keitheis
0
120
How Android Uses Data Structures Behind The Scenes
l2hyunwoo
0
480
実用的なGOCACHEPROG実装をするために / golang.tokyo #40
mazrean
1
290
AI Coding Agentのセキュリティリスク:PRの自己承認とメルカリの対策
s3h
0
230
Deep Dive into Kotlin Flow
jmatsu
1
360
JSONataを使ってみよう Step Functionsが楽しくなる実践テクニック #devio2025
dafujii
1
620
Featured
See All Featured
BBQ
matthewcrist
89
9.8k
Learning to Love Humans: Emotional Interface Design
aarron
273
40k
Writing Fast Ruby
sferik
628
62k
Context Engineering - Making Every Token Count
addyosmani
3
58
Building a Scalable Design System with Sketch
lauravandoore
462
33k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
32
1.6k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
920
Designing Dashboards & Data Visualisations in Web Apps
destraynor
231
53k
The Language of Interfaces
destraynor
161
25k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
285
14k
A better future with KSS
kneath
239
17k
Faster Mobile Websites
deanohume
309
31k
Transcript
KOTLIN FLOW JOSÉ CAIQUE
produce(capacity = 20) { (0..10).forEach { send(it) println("sent $it") }
} //emmit : 1,2,3 … val intFlow = flow { for (i in 0 until 10) { emit(i) println("sent flow $i") } } // intFlow.collect{ } // 1,2,3… HOT CHANNEL COLD STREAM implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.0-M1'
@ExperimentalCoroutinesApi public interface Flow<out T> { @InternalCoroutinesApi public suspend fun
collect(collector: FlowCollector<T>) } BackPressure by Default
BUILDERS ▸ (0..2).asFlow() ▸ flow{ emit(1) } ▸ flowOf(1, 2,
3, 4, 5) ▸ channelFlow { send(1) } ▸ emptyFlow<T>()
(0..1).asFlow() .map { println("Thread0 ${Thread.currentThread().name}") it*it } .filter { println("Thread1
${Thread.currentThread().name}") it % 4 == 0 } .flowOn(Dispatchers.IO) .map { println("Thread2 ${Thread.currentThread().name}") it * 2 } .flowOn(Dispatchers.Default) Thread0 DefaultDispatcher-worker-2 Thread1 DefaultDispatcher-worker-2 Thread0 DefaultDispatcher-worker-2 Thread1 DefaultDispatcher-worker-2 Thread2 main
//requestA(Flow) -> 1000L //requestB(Flow) -> 2000L requestA() .zip(requestB()) { requestA,
requestB -> requestA + requestB }.collect { println(it) } Total: ~2100L
//requestA(suspend) -> 1000L //requestB(suspend) -> 2000L channelFlow<Pair<Int, String>> { val
result1 = async { requestA() } val result2 = async { requestB() } val result3 = result1.await() to result2.await() send(result3) }.collect { println(it) } // buffer, still cold stream Total: ~2100L
val myFlow = flow { // GlobalScope.launch { // is
prohibited // launch(Dispatchers.IO) { // is prohibited // withContext(CoroutineName("myFlow")) // is prohibited emit(1) // OK coroutineScope { emit(2) // OK -- still the same coroutine } }
channelFlow { launch(IO){ send(requestA()) } launch(Main) { send(requestB()) } }.collect
{ println(it) }
val broadcast: ConflatedBroadcastChannel<User> // emitting launch { broadcast.send(user) } //
listening broadcast.consumeEach { service .retrieve(it) .map { it.getOrNull() } .collect { it?.let { … } } } //close broadcast.close()
EXTENSIONS ‣ broadcastIn ‣ buffer ‣ collect ‣ combineLatest ‣
conflate ‣ count ‣ debounce ‣ delayEach ‣ delayFlow ‣ distinctUntilChanged ‣ distinctUntilChangedBy ‣ drop ‣ dropWhile ‣ filter ‣ filterIsInstance ‣ filterNot ‣ filterNotNull ‣ first ‣ flatMapConcat ‣ flatMapMerge ‣ flattenConcat ‣ flattenMerge ‣ flowWith ‣ fold ‣ map ‣ mapNotNull ‣ onEach ‣ onErrorCollect ‣ onErrorReturn ‣ produceIn ‣ reduce ‣ retry ‣ sample ‣ scan ‣ scanFold ‣ scanReduce ‣ single ‣ singleOrNull ‣ switchMap ‣ take ‣ takeWhile ‣ toCollection ‣ toList ‣ toSet ‣ transform ‣ zip
fun <T> Flow<T>.startWith(start: T) = flow { collect { value
-> emit(start) emit(value) } } flowOf("Caique") .startWith("Jose") .collect { println(it) } // José // Caique EASY TO CREATE EXTENSIONS
MORE EXTENSIONS ARE COMING https://github.com/Kotlin/kotlinx.coroutines/issues/1263 https://github.com/Kotlin/kotlinx.coroutines/issues/1261 https://github.com/Kotlin/kotlinx.coroutines/issues/1247 https://github.com/Kotlin/kotlinx.coroutines/issues/1186
JOSÉ CAIQUE ▸ Software Engineer ▸ Computer Science by UFS
▸ Android Tech Lead at Stone ▸ Speaker
J C A I Q U E _ J O
S E C A I Q U E J O S E C A I Q U E T H A N K S