Hey there Using Flows from KMM in Swift is possible thanks t

Question

Hey there Using Flows from KMM in Swift is possible thanks to <https github com rickclephas KMP NativeCoroutines> white check mark But how can we pass Swift publishers AnyPublisher lt Boolean gt to KMM as Flows

Marc Reichelt · Answer

Say we have this code in Kotlin ```fun doSomething flow Flow lt Boolean gt ``` Now we have a publisher like this in Swift ```func swiftFunction publisher AnyPublisher lt Boolean Never gt doSomething publisher asFlow ``` Is there anything like `asFlow ` which currently is not available or what would you do instead

Rick Clephas · Answer

Not really helpful but I am <https github com rickclephas KMP NativeCoroutines issues 42|planning> on adding support for such Swift to Kotlin cases

Marc Reichelt · Answer

Thank you for answering and thank you for providing this library which is really useful to us clap tada I saw the issue you referenced but thought it would be a different problem slightly smiling face

Rick Clephas · Answer

The whole issue is somewhat more complicated but it mainly consists of 3 parts adding support for `Flow` arguments adding support for `suspend` arguments adding support for Swift implementations of coroutine declarations e g subclassing a Kotlin class in Swift and overriding a suspend or Flow declaration The first two aren t that complex the later causes more headache sweat smile

Marc Reichelt · Answer

Yeah it sounded a bit more complicated that s why I was asking slightly smiling face

Marc Reichelt · Answer

We ll try to implement something ourselves maybe we can just use `MutableSharedFlow` for example

Marc Reichelt · Answer

I just wondered how others do it because this seems to be a problem which more people should run into Maybe most people just add a parameter like `onValueChanged Boolean gt Unit` and call it a day smile

Rick Clephas · Answer

Yeah depending on the use case that might actually work I guess it really depends on the architecture if you need something like this E g if you expose ViewModels you are less likely to have to expose a `Flow` back to Kotlin

Marc Reichelt · Answer

TL DR So we tried it out a bit and it s possible to make this work The tricky bit is where to store the subscription of Combine somewhere along with the type conversions for KotlinInt KotlinBoolean etc We stopped investigating this for now Hopefully we ll have something to share sometime in the future