this may be a dumb question, but I created a KN cl...

# kotlin-native

[toomanyeduardos]

this may be a dumb question, but I created a KN class that has 2 functions: one is a regular fun and the other one is a suspend fun, which is using coroutines to make a network call.

on android, i can see both functions from this class. i can call them, and life is good.

on ios, I can only see the function that is a regular fun. the suspend fun is not visible at all.

what did i miss? does iOS not support suspending functions from coroutines?

[yuya_horita]

suspend fun is not exported to .framework on iOS at this time.

[toomanyeduardos]

😞

[yuya_horita]

in common, define suspend fun

[toomanyeduardos]

is there an alternative for this?

[yuya_horita]

in actual, use it in coroutine

[yuya_horita]

for example

[jonnyzzz]

you may understand the suspend function as a function with callback, that is executed when function is completed. You cannot call such function from Java, and objc.
The workaround is wrap the coroutine with an ordinary function.
https://github.com/Kotlin/kotlinx.coroutines/issues/470#issuecomment-440080970
That may help

[toomanyeduardos]

oh. ok @yuya_horita, I can do that for android.
what do you for iOS in the KN code?

[yuya_horita]

yes, thank you @ jonnyzzz

[yuya_horita]

I defined function like below in common module

suspend fun hello(): String {
        try {
            return helloRepository.hello()
        } catch (e: Throwable) {
            throw e
        }
}

[yuya_horita]

and, did in actual ios module

[yuya_horita]

fun HelloService.sendHello(block: (String?, Error?) -> Unit) {
    launch(block) {
        [e-mail]()
    }
}

[yuya_horita]

I use this actual function from swift code.

[toomanyeduardos]

ok. thanks

[yuya_horita]

be careful using correct CoroutineDispathcer

[yuya_horita]

internal class MainScope: CoroutineScope {
    private val context = MainDispatcher()
    private val job = Job()
    private val exceptionHandler = CoroutineExceptionHandler { _, _ -> }

    override val coroutineContext: CoroutineContext
        get() = context + job + exceptionHandler
}

private class MainDispatcher: CoroutineDispatcher() {
    override fun dispatch(context: CoroutineContext, block: Runnable) {
        dispatch_async(dispatch_get_main_queue()) { block.run() }
    }
}

[yuya_horita]

this will help you

[toomanyeduardos]

who's calling that last chunk of code?

[yuya_horita]

sorry, which code?

[yuya_horita]

MainScope?

[toomanyeduardos]

yes

[toomanyeduardos]

MainScope and MainDispatcher

[yuya_horita]

MainDispatcher is used just for MainScope

[yuya_horita]

and

[yuya_horita]

internal fun <T> launch(block: (T?, Error?) -> Unit, suspendBlock: suspend CoroutineScope.() -> T) {
    MainScope().launch {
        try {
            val response = suspendBlock()
            block(response, null)
        } catch (e: Error) {
            block(null, e)
        }
    }
}

[toomanyeduardos]

but is it used by common? jvm?
kotlin android app?

[yuya_horita]

in common, suspend function is defined, so there is no problem for kotlin android app.

[yuya_horita]

this is used by ios app

[toomanyeduardos]

what does iOS call?

[yuya_horita]

above sendHello function

[yuya_horita]

like

in Swift
Services.helloService.sendHello {  response, error in
        }

sendHello is just a wrapper for hello() suspend function.

[toomanyeduardos]

ok. cool. thanks!

[yuya_horita]

yes!