pollWithState

Creates a flow that continuously polls elements using the f function, starting with an initial state initial.

The flow stops when the shouldStop function returns true for the current state or when the coroutine context is no longer active.

The primary difference between this function and the regular poll function is that pollWithState maintains state from the previous polling iteration. This can be particularly useful in situations where some level of state control is required, such as HTTP pagination, stream polling, and more.

data class ApiResponse<T>(
    val items: List<T>,
    val nextPage: Int?
)

suspend fun fetchPage(page: Int): ApiResponse<String> = // Fetch data from some API

pollWithState(
    initial = 1, // Initial page number
    shouldStop = { it == -1 } // Stop when there are no more pages to fetch
) { currentPage ->
    val response = fetchPage(currentPage)
    val nextState = response.nextPage
    val items = response.items

    (nextState ?: -1) to items
}.collect { item -> println(item) }

Parameters