so I created a new KMP project, got some stuff up and working across Android & Desktop, and I wa...

# multiplatform

[Adam Brown]

so I created a new KMP project, got some stuff up and working across Android & Desktop, and I want to add iOS now, which the project wizard didn't create anything for. Is there a good tutorial or anything for adding iOS to a KMP (not KMM) project after the fact?

[ribesg]

It’s kinda simple nowadays, basically 1) Use a Mac 2) add target ios() 3) Add folder for sourceSet iosMain

There’s a little bit more to do if you’re on a M1 Mac but that’s really the gist of it

[Matti MK]

Going on a slight tangent here, but could you elaborate on the extra steps required for M1? Thanks 👍

[ribesg]

Yes! With a M1 Mac you will want to run an Arm64 simulator when testing and not a X64 simulator. For this you need to add another iOS target, iosSimulatorArm64()

ios() is a shortcut for a bunch of stuff that iosSimulatorArm64() does not do, so you have to do it yourself (it’s not much)

ios() creates both iosArm64() and iosX64() targets, as well as sourceSets iosMain, iosArm64Main, iosX64Main for source files and iosTest, iosArm64Test and iosX64Test for tests, then links them together (iosArm64Main.dependsOn(iosMain), etc.).

iosSimulatorArm64() does not do the linking to the “iOS-common” `iosMain`/`iosTest` sourceSets, so you have to do that manually.

[Matti MK]

Great info, thanks for sharing 👍

I’ve been developing apps on KMM for about 9mo now, but I’ve got an Intel so didn’t know these differences with the sourceSets and targets

[ribesg]

I don’t have a M1 Mac yet so this is still theory for me. I also don’t know if you can still run a X64 simulator on M1 using the bridging stuff which I forgot the name of, or not at all. What I can tell you is that you can already add the arm64 simulator target to a KMP project and compile it on a X64 Mac, that I tested and it works.

[Landry Norris]

I don’t think that the iosArm64Simulator target is strictly required for M1. I don’t use it currently on my M1, and it looks like it falls back to x86_64. It’s possible I set that up using Rosetta 2 in the past, but I don’t have any issues currently.

[Adam Brown]

So, adding ios() to the common module and resyncing does indeed break the other modules, then adding their source sets allows me to fill in that code. But the next step I think is that I need a seperate iOS module, much like how Desktop and Android have their own modules that actually include and run the common code. I have very little ios experience, was woundering if there were any good tutorials on dropping a new ios project in there and getting it to reference the common iOS module

[Adam Brown]

ah, this looks like it: https://kotlinlang.org/docs/multiplatform-mobile-integrate-in-existing-app.html#connect-the-framework-to-your-ios-project

[Landry Norris]

If you look at the compose experimental samples, they show how to create the whole app in Kotlin without a separate xcode project.

[Adam Brown]

Oh really? I want to have a swift UI though

[Adam Brown]

the sort of frustrating thing, is if you just follow the happy path, File -> New Project, create a multiplatform project with iOS support, on a Mac, then try to build it, it fails in a variety of ways.

[Adam Brown]

and all of the examples i've found online, are using a fairly different project structure than what the project generator creates, so its hard to know exactly how to make it work by just looking at them

[Landry Norris]

That's fair. I would love direct Swift support in Kotlin, but until then, you need swift for SwiftUI