SharedFlow for events in Android Kotlin - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a MutableSharedFlow for events.

Android Kotlin

val eventFlow = MutableSharedFlow<[1]>()

Drag options to blanks, or click blank then click option'

AString

BBoolean

CInt

DFloat

Attempts:

3 left

💡 Hint

Common Mistakes

Using a numeric type when events are text messages.

Forgetting to specify the type parameter.

The MutableSharedFlow is declared with the type of events it will emit. Here, String is used for simple text events.

2fill in blank

medium

Complete the code to emit an event string into the SharedFlow.

Android Kotlin

viewModelScope.launch {
  eventFlow.[1]("ButtonClicked")
}

Drag options to blanks, or click blank then click option'

Acollect

Bsubscribe

Cemit

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Using collect which is for receiving, not sending.

Using send which is for Channels, not SharedFlow.

To send an event to the SharedFlow, use the emit function inside a coroutine.

3fill in blank

hard

Fix the error in collecting events from the SharedFlow in a lifecycle-aware way.

Android Kotlin

lifecycleScope.launchWhenStarted {
  eventFlow.[1] { event ->
    handleEvent(event)
  }
}

Drag options to blanks, or click blank then click option'

Asubscribe

Bemit

Claunch

Dcollect

Attempts:

3 left

💡 Hint

Common Mistakes

Using emit which is for sending events.

Using subscribe which is not a Kotlin Flow function.

To receive events from a SharedFlow, use the collect function inside a coroutine.

4fill in blank

hard

Fill both blanks to create a SharedFlow that replays the last event and has no extra buffer.

Android Kotlin

val eventFlow = MutableSharedFlow<String>(replay = [1], extraBufferCapacity = [2])

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A1

B0

C2

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Setting replay to zero loses the last event for new subscribers.

Setting extraBufferCapacity too high can cause unexpected buffering.

Setting replay = 1 makes the flow replay the last event to new subscribers. extraBufferCapacity = 0 means no extra buffering.

5fill in blank

hard

Fill all three blanks to collect events from SharedFlow in a Compose UI using LaunchedEffect.

Android Kotlin

LaunchedEffect(Unit) {
  eventFlow.[1] { event ->
    when(event) {
      [2] -> showToast("Clicked")
      [3] -> showToast("Error")
    }
  }
}

Drag options to blanks, or click blank then click option'

Acollect

B"ButtonClicked"

C"ErrorOccurred"

Demit

Attempts:

3 left

💡 Hint

Common Mistakes

Using emit instead of collect to receive events.

Using incorrect event string literals in the when statement.

Use collect to receive events. Match event strings to show appropriate messages.