"No visible @interface for 'MySwiftFile' declares the selector '****'" in iOS framework

Question

I've been having trouble with using Swift in an ObjC framework in iOS. My framework has Objective-C code, which I want to call Swift code from.

I think I have created the bridging properly, I'll show below what I've done.

MySwiftFile.swift :

open class MySwiftFile: NSObject {
  var varDummy : RandomType? = nil
  open func setupDummy(param1 : RandomType1) {
    varDummy = RandomType(p: param1)
  }
}

MyObjCFile.m :

@class MySwiftFile;
#import "MyFramework/MyFramework-Swift.h"

@interface A : NSObject<...>
@property(atomic) MySwiftFile *mySwiftFile;

.....
@end
@implementation Aclass
......
@end

@interface B ()
....
@property(readonly, nonatomic) A *refA;
@end

@implementation B
....
- (void)methodCalledSomewhere:(RandomType1 *)type {
   ....
   refA.mySwiftFile = [[MySwiftFile alloc] init];
   [refA.mySwiftFile setupDummy: type];   <====THIS LINE PRODUCES THE ERROR
}
....

To sum it up, I want to init the property and call a function of a Swift object from ObjC code. Xcode seems to recognize MySwiftFile as a valid type, then how come it does not allow me to call the "setupDummy" method?

The errors are 2:

No visible @interface for 'MySwiftFile' declares the selector 'setupDummy:'
No visible @interface for 'MySwiftFile' declares the selector 'setupDummy'

Your `MySwiftFile` class is not exposed to the Obj-C runtime. Search for `@objc`, `@objcMembers`, ... I can't find the best answer to mark this as a duplicate, but there's a lot of them. — zrzka, Jul 01 '20 at 14:53
@zrzka Didn't work adding ```@objc``` or ```@objcMembers```. Same error is produced : No visible @interface for 'MySwiftFile' declares the selector 'setupDummy:' — fff, Jul 01 '20 at 16:09

score 2 · Accepted Answer · answered Jul 01 '20 at 18:11

First problem is that you forget to expose it to the Objective-C. Either add @objcMembers to expose everything ...

@objcMembers
open class MySwiftFile: NSObject {
    ...
}

... or just add @objc to your setupDummy function ...

@objc
open func setupDummy(param1: String) {
    ...
}

Second problem is about how the function name is translated to Objective-C ...

@objc func setupDummy(param1 : RandomType1) -> setupDummyWithParam1:
@objc func setupDummy(_ param1: RandomType1) -> setupDummy:
@objc(setupDummy:) func setupDummy(param1: String) -> setupDummy:

... which means that adding just @objc wont work. You have to either change the Swift function signature or use setupDummyWithParam1: in your Objective-C or keep the Swift function signature & use @objc(<name>) to change the Objective-C selector.

Thanks, in the meantime I checked in the MyProj-Swift.h file and, in fact, setupDummyWithParam1 function was declared there. Cheers — fff, Jul 02 '20 at 14:03

"No visible @interface for 'MySwiftFile' declares the selector '****'" in iOS framework

1 Answers1