transformLatest

fun <T, R> Flow<T>.transformLatest(transform: suspend FlowCollector<R>.(T) -> Unit): Flow<R>

Returns a flow that produces element by transform function every time the original flow emits a value. When the original flow emits a new value, the previous transform block is cancelled, thus the name transformLatest.

For example, the following flow:

flow {
emit("a")
delay(100)
emit("b")
}.transformLatest { value ->
emit(value)
delay(200)
emit(value + "_last")
}

produces a b b_last.

This operator is buffered by default and size of its output buffer can be changed by applying subsequent buffer operator.

Sources

common source
Link copied to clipboard