i have a sealed class in mu kotlin usecase but the...

# multiplatform

[Robert Munro]

i have a sealed class in mu kotlin usecase but the types arent available in iOS - just wondering if there is anything i have to do to get the sealed subclasses to be generated (compiler flag or something?). The module is domainKmm

class LoginUseCase {
sealed class State {
    object Initial : State()
    object StartAuthorization : State()
    object AuthorizationTokenReceived : State()
    object AccessTokenReceived : State()
    object SuppliersLoading : State()
    data class SuppliersLoaded(val suppliers: List<Supplier>) : State()
    data class ConfirmSupplierChange(val chosenSupplier: Supplier, val currentSupplier: Supplier) : State()
    data class SupplierLoadError(val e: Throwable) : State()
    object NoSupplier : State()
    data class LoggedInSuccess(val isNewSupplier: Boolean) : State()
}
}

So i can use DomainKmmLoginUseCase and DomainKmmLoginUseCase.State but i cant use DomainKmmLoginUseCase.State.Initial

I cant find any declaration of things like Initial or StartAuthorization in the generated iOS header file.
is there any guidance on using sealed classes in iOS? i've seen they dont really map to swift well - but havent been able to find any usage examples.

[Robert Munro]

stupid question?

[novikau]

If Initial is not declared as internal it should be generated as DomainKmmLoginUseCase.StateInitial (without a dot between State and Initial) in the iOS header file. But you're right, the sealed classes are mapped to swift as regular classes, so you will loose the restricted class hierarchy of the sealed classes when you work with these classes in swift.

[Robert Munro]

so i just get DomainKmmLoginUseCase.State with no subclasses. I get all the member `fun`s of LoginUseCase - so for some reason its not generating the children of the sealed State class. I'm on 1.6.20.

[novikau]

so i just get DomainKmmLoginUseCase.State with no subclasses.

for Initial class (a subclass of State sealed class) you should use DomainKmmLoginUseCase.StateInitial. At least this is how I see it is generated in my case for the nested classes of a 3d level. I'm on 1.7.0, so maybe something has been changed in the latest updates.

[Robert Munro]

yes so DomainKmmLoginUseCase.StateInitial doesn't get generated for me.

[Robert Munro]

I updated to 1.7.20 but classes still not generating.

[novikau]

You said that the outer class is called LoginUseCase where does DomainKmmLoginUseCase come from?

[Robert Munro]

That is the generated classname

[Robert Munro]

so in kotlin its LoginUseCase swift its DomainKmmLoginUseCase

[novikau]

I don't know. It looks like you have some tricky build configuration because I added a class from the snippet above to my kmm module and here is what I have in the generated header:

__attribute__((objc_subclassing_restricted))
__attribute__((swift_name("LoginUseCase")))
@interface CSCLoginUseCase : CSCBase
- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
+ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
@end;

__attribute__((swift_name("LoginUseCase.State")))
@interface CSCLoginUseCaseState : CSCBase
@end;

__attribute__((objc_subclassing_restricted))
__attribute__((swift_name("LoginUseCase.StateInitial")))
@interface CSCLoginUseCaseStateInitial : CSCLoginUseCaseState
+ (instancetype)alloc __attribute__((unavailable));
+ (instancetype)allocWithZone:(struct _NSZone *)zone __attribute__((unavailable));
+ (instancetype)initial __attribute__((swift_name("init()")));
@property (class, readonly, getter=shared) CSCLoginUseCaseStateInitial *shared __attribute__((swift_name("shared")));
@end;

So there is a module prefix in the generated class name, but only for Objective C. For swift there is a different name defined (without a prefix) and I can access the kotlin classes from swift code by this name.

[Robert Munro]

yeah I'm not sure what i could have done to make it have differently - there are a few modules in the project - possibly something is getting messed up since its included through another module (domainKmm is included via sharedKmm - as there classes are created via Koin).

I omitted the methods in the class above for brevity. This is what i get though..

__attribute__((objc_subclassing_restricted))
__attribute__((swift_name("DomainKmmLoginUseCase")))
@interface SharedKmmDomainKmmLoginUseCase : SharedKmmBase
- (instancetype)initWithAuthStateManager:(id<SharedKmmDomainKmmIAuthStateManager>)authStateManager authChecks:(id<SharedKmmDomainKmmUserAuthorizationChecker>)authChecks jwtTokenParser:(SharedKmmDomainKmmJwtTokenParser *)jwtTokenParser userMapper:(SharedKmmDomainKmmUserMapper *)userMapper prefs:(SharedKmmDomainKmmAppPreferences *)prefs analytics:(SharedKmmDomainKmmAnalytics *)analytics supplierApiGatewayRepository:(id<SharedKmmDomainKmmSupplierApiRepository>)supplierApiGatewayRepository newLoggedInUserUseCase:(SharedKmmDomainKmmNewLoggedInUserUseCase *)newLoggedInUserUseCase networkErrorBus:(id<SharedKmmDomainKmmINetworkErrorBus>)networkErrorBus __attribute__((swift_name("init(authStateManager:authChecks:jwtTokenParser:userMapper:prefs:analytics:supplierApiGatewayRepository:newLoggedInUserUseCase:networkErrorBus:)"))) __attribute__((objc_designated_initializer));
- (SharedKmmDomainKmmLoginUseCaseState *)_getState __attribute__((swift_name("_getState()")));

possibly if i include domainKmm directly it might work - I guess that would be a bug tho. not sure.

[Robert Munro]

OK! i moved LoginUseCase to the sharedKmm module and the sealed classes generate OK.

Does this seem like a bug?

[novikau]

As for me it seems like a bug. Try to look for a similar issue in the JetBrains' bug tracker or report them a bug