How can we use the result of a first routing to call the 2nd one (reformulating my previous question...

# coroutines

[Samer Hobeika]

How can we use the result of a first routing to call the 2nd one (reformulating my previous question)

[bloder]

you need something like this?

suspend fun getFirstResult() : Data? = try {
    getData().await()
} catch(e: Exception) {
    null
}

suspend fun getSecondResult(data: Data) {}

fun getContent() = launch {
    getFirstResult()?.let{ getSecondResult(it) }
}

[streetsofboston]

You’d probably want to change getContent a bit:

fun CoroutineScope.getContent() = async { 
    getFirstResult()?.let { getSecondResult(it) }
}

[Samer Hobeika]

I see

[Samer Hobeika]

Yea i would probably use async instead of launch

[bloder]

depends on what you want to do, no @streetsofboston? Example: I call that from my view that does not have any dependency of coroutines or anything like that and in my getContent I have at the final a handleResponse() to make the communication to my view with states, then my getContent needs to launch, or am I missing something?

[Samer Hobeika]

in my case, i’m showing a spinner when the user taps on a button, it will stay visible until i have the result of the 2nd function

[streetsofboston]

Yes, it depends on the use-case, but the original poster used async. And there’s a need of a CoroutineScope to call async (or launch).

[Samer Hobeika]

yes , i’ll be using GlobalScope

[streetsofboston]

Be very very careful using GlobalScope, though.

[Samer Hobeika]

can you elaborate?

[streetsofboston]

You lose structured concurrency when using GlobalScope. Let me find the article that explains this (better than discussing it here in a thread)

[bloder]

https://medium.com/@elizarov/the-reason-to-avoid-globalscope-835337445abc

[Samer Hobeika]

Okay thank you @bloder ++

[bloder]

this is a good article that talks about it

[streetsofboston]

That one is a great article and this one:
https://medium.com/@elizarov/structured-concurrency-722d765aa952

[Samer Hobeika]

I’m also using a DI

[streetsofboston]

That should not matter. 🙂

But you can use DI to inject a TestCoroutineScope (or a TestCoroutineDispatcher) for your unit-tests while injecting actual Dispatchers (IO, Default, Main) for your actual app.

[Samer Hobeika]

ok ok great