cannot find the interface declaration for RealmSwiftObject

[hitendradeveloper]

I have just started working on watch app, I want to share my Realm model classes to watch app also,

To make data available for watch app using NSKeyedArchiver and NSKeyedUnarchiver using WatchConnectivity, I have make CocoaTouch Framework which includes model classes, and added "pod 'RealmSwift'" to framework target.

When I compile the Project, it is giving error ''

I have changed SWIFT_INSTALL_OBJC_HEADE to NO

[bigfish24]

Is RealmSwiftObject a custom class of yours?

[hitendradeveloper]

No its not custom class, its class of Realm framwork

[jpsim]

No its not custom class, its class of Realm framwork

RealmSwiftObject is now the fully qualified Objective-C name of RealmSwift.Object as of #2979, so you shouldn't name your models by that name. I'll update the docs to reflect this.

[jpsim]

Actually, since the compiler should prevent you from declaring classes named RealmSwiftObject, there's not much more that documentation about it would do to help.

@hitendradeveloper could you please your entire Podfile here? This error could happen if you're using mismatched versions of the 'Realm' and 'RealmSwift' pods.

[hitendradeveloper]

I have used pods as below in iOS app target.

REALM SWIFT : Replacement of coreData

use_frameworks! pod 'RealmSwift'

also added same pod to watchOS2 extension and my ModelKit framework.

[jpsim]

@hitendradeveloper have you made any progress on this since you last posted here? If not, I could spend some time trying to reproduce this next week.

[hitendradeveloper]

@jpsim No, there is not any progress, still getting the same error.

[danielhour]

@jpsim I'm not sure if this is the same issue but I'm getting the same error message...

I have a predominantly Swift project so am using RealmSwift. However, I need to do a little Objective-C (that doesn't use Realm). However, when i #import "ProductModuleName-Swift.h" as Apple's Docs suggest for a mix-and-match project... the "cannot find the interface interface declaration for RealmSwiftObject" error prevents me from compiling.

Has your team encountered this at all? Thanks in advance for any help/advice you have!

[jpsim]

I have yet to prepare a sample project that reproduces the issue, so no we haven't encountered this ourselves. If you could share one, that could save some time!

[danielhour]

@jpsim absolutely! here you go: https://github.com/danielhour/RealmSwiftSample

thanks again for taking a look at this!

[jpsim]

Thanks for the project, @danielhour! I could easily trigger the compilation failure.

To be clear, using Realm Swift from Objective-C is unsupported. This is stated in the first line of our Realm Swift docs:

If you’re looking to use Realm from Objective-C, or from mixed Objective-C & Swift apps please see Realm Objective-C instead.

Realm Objective-C is designed to be used from Objective-C and/or Swift and we support its usage in mixed projects. So I encourage you to use Realm Objective-C if you need to use Realm from Objective-C.

@danielhour in your case, you're not actually trying to use Realm Swift from Objective-C, but rather you need to access some other declarations from the Swift part of your app in the Objective-C part of your app. So you're "playing within the rules" so to speak. In that case, you can hide your Realm model classes from your -Swift.h header by marking them private:

private class RObject: Object

By doing that your project compiles for me.

[danielhour]

@jpsim so i actually tried that and while that removes that error.. then my other swift files can no longer see that class. is there another way to hide it? thanks.

[jpsim]

Manually editing the -Swift.h file to avoid redeclaring your Realm models? You'd have to stop Xcode from auto-generating the file and pass in your own.

[hitendradeveloper]

@jpsim I am using mix and match environment,

I was just trying to create modelKit, so I can share the pure swift classes between watch and iOS app, all the classes are subClass of Object, Object class is part of Realm.

I have not used and Objective-C code, compiler automatic generates the -Swift.h header file, that's why I am getting the error.

About your solution to make private, in this case how we can share classes with other target, they will not visible anymore by making them private.

[jpsim]

Thanks for sharing, I'll reopen this and take another look for potential workarounds later.

[hitendradeveloper]

@jpsim Is there any progress about the issue ?

[jpsim]

I'm working on a fix in Swift's PrintAsObjC.cpp.

[jpsim]

I've just filed SR-805 to track this on Swift's bug tracker.

Until this is fixed, I'd encourage you to work around this by only including the -Swift.h file from an Objective-C file, re-exposing the methods you want to use, and importing that from your Objective-C++ file.

[paandahl]

Hacky workaround:

There is no way to exclude classes from the *-Swift.h without making them private, but what you can do is open the Swift.h file, remove all classes with errors (or just keep the class/es you need to access), copy what's left into a new file (e.g. SwiftBridge.h) in your project, and import that one instead.

This will of course need to be redone to add new classes / methods. For me that's not really an issue though, as I only need to call one Swift-class from ObjC, that doesn't change often.

The class reference looks like this:

SWIFT_CLASS("_TtC10tripfinger21TripfingerAppDelegate")

That's the module name and the class name, prefixed by the length of their names. So if they change names, you also have to go through the process again.

[gereons]

I'm in the same boat, with a Swift and Obj-C++ mix.

Since none of the Realm-related classes are ever used on the ObjC-side, I can work around this problem by having #define RealmSwiftObject NSObject just before the #import "xyz-Swift.h"

[hitendradeveloper]

Looking forward for the progress on this issue. Any updates ?

[jpsim]

No updates on our side. SR-805 is still up for grabs. @hitendradeveloper is this something you're interested in fixing in the Swift compiler?

[vincent-peng]

@gereons Thanks for the workarounds, we are currently encounter the same issue on our end and lucky saw this workaround. And btw, #define RealmObjectSwift NSObject should be -> #define RealmSwiftObject NSObject

[gereons]

@vincent-peng Thanks, I've edited my comment to reduce further confusion.

[jkmathew]

Any good news with swift 4.0? I checked @jpsim 's sample code PrintAsObjcBug with Xcode 9 beta 1. But getting same error. This will remain impossible in future too?

[devolaw]

I'm in the same boat, with a Swift and Obj-C++ mix.

Since none of the Realm-related classes are ever used on the ObjC-side, I can work around this problem by having #define RealmSwiftObject NSObject just before the #import "xyz-Swift.h"

This is still working for me to fix the same error on Xcode10.2 with Swift5, realm-cocoa v3.14.0

[3a4oT]

Cannot find interface declaration for 'RealmSwiftObject', superclass of MyObject. Mix Swift 5 and Obj-C.

[innoreq]

dito, Swift-only (except obj-c in imported frameworks).

[DanielAsher]

❗️Swift Compiler Error: Cannot find interface declaration for 'RealmSwiftObject', superclass of 'MyRealmObject'. Pure Swift 5.

[3a4oT]

In my case it was related to Carthage bug.

[Tapestes]

@3a4oT, how did you resolve the Carthage bug? Thanks.

[3a4oT]

depends on https://github.com/Carthage/Carthage/pull/2748 and https://github.com/Carthage/Carthage/pull/2723. Carthage should release later this week. For now I have postponed Xcode 10.2 migration.

[DanielAsher]

depends on Carthage/Carthage#2748 and Carthage/Carthage#2723. Carthage should release later this week. For now I have postponed Xcode 10.2 migration.

The build should work for Generic iOS Device, but fails for builds to simulators.

[krystiank907]

I have the same problem: Xcode 10.2 Swift 5.0 Carthage 0.33.0 I writing only in Swift, don't have Objective-C in my project

Update Carthage does't resolve this issues

[ivitoria]

I have updated to last realm-cocoa version (3.14.1) where it is supposed to be fixed, but still failing. Have anyone find a solution?

[jweg29]

For me it was an issue with Carthage. Updating to Carthage 0.33.0 resolved all the issues.

[allanweir]

This seems to be working for me now - with Realm 3.14.1 and the pre-built binary. Carthage 0.33 but since it's pre-built maybe that doesn't matter? I also deleted the cached version in ~/Library/Caches/org.carthage.kit and I deleted the binaries from my Carthage/Build folder too

[devolaw]

This seems to be working for me now - with Realm 3.14.1 and the pre-built binary. Carthage 0.33 but since it's pre-built maybe that doesn't matter? I also deleted the cached version in ~/Library/Caches/org.carthage.kit and I deleted the binaries from my Carthage/Build folder too

Clear all the caches you mentioned did the trick.

[MrMatten]

I still see this issue Obj-C + Swift 5