Hello everyone, I am a Kotlin newbie and are looking for a way to resume a Flow after an exception h...

# flow

[Christian S.]

Hello everyone, I am a Kotlin newbie and are looking for a way to resume a Flow after an exception has been thrown by the emitter. I want to adhere to Exception Transparency. I have seen a workaround on SO (https://stackoverflow.com/a/63886110) but wanted to ask if you know an easier / less custom solution. Thanks!

[gildor]

You can use catch operator to handle exception

[Christian S.]

Thanks, Andrey, but my requirement is to not terminate the flow when an exception in the emitter occurs. When the exception is catched with a catch operator the flow still terminates. To solve this, my colleague just had a simple solution: just emit(..) a default/error value in case an exception has occurred in the emitter before and move the emit(..) call outside of the try-block. This adheres to Exception Transparency.

[gildor]

But it’s up to flow terminate or not, right?
The only what you can do is restart flow

[gildor]

Code from this SO question just should be:

.flatMapLatest { fetchSomeData().catch { //any default }
            .onEach { handleData() }
            .collect()

[Christian S.]

What I need(ed) is:

flow {
    val result = try {
        // call some REST API and return the result
    } catch (e: Exception) {
        // return some default/error value 
    }
    emit(result)
}

So simple that I felt stupid asking the initial question.

[gildor]

yep, this what I meant, just example from SO returns flow