Are there examples on how to handle exceptions during

launch

blocks? I have a method created like so:

suspend fun <T> Deferred<T>.awaitOrRedirect(context: Context): T? =
    try {
        await()
    } catch (e: Exception) {
        logd("Error, redirect to Login")
        LoginActivity.launch(context)
        null
    }

But the errors seem to just pass through and cancel the coroutines altogether without launching the activity. To give more details, I’m building for Android, and I’m using

CoroutineScrope

within the activity that is calling the method. I’m using

launch

as it is used for most of the example code, and it looks like the only difference with

async

is that

async

cancels the parent and returns a deferred value. I also see that there are `CoroutineExceptionHandler`s, though I’m not sure if that is the right fit here.

But in your example there is no launch, only Deferred and await Your code looks fine, should work

To give more details, this is for the coroutine implementation for retrofit. I am calling this method in a launch within an Activity. The expectation that an exception will trigger a login attempt as the api call has failed. For some reason the launching doesn't always work, and the app stops as a whole.

coroutine implementation for retrofit

which one?

This adapter: https://github.com/JakeWharton/retrofit2-kotlin-coroutines-adapter This is also my first attempt at jetpack, so the problem could potentially be elsewhere. I agree that okhttp interceptor is a better way, but it doesn't have access to the context necessary to launch the login activity. Doing so with coroutines should also be possible, so I want to use this as an opportunity to better understand how it works

but it doesn’t have access to the context necessary to launch the login activity

Just pass application context to Interceptor’s constructor, no problems there, just start activity in a new task (you cannot start it in the same task without activity context) Another approach: interceptor just send some event that can be caught by current active activity and show login screen on the same task

I currently can no longer replicate the issue so it may be a problem elsewhere. Using the interceptor approach is an interesting idea, and I think that passing the exception to the coroutine will also help with stopping other api requests as it redirects to login. Thanks for your help!