Using GTM v5 TAGCustomFunction in Swift - ios

Question

I'm integrating GTM v5 (GTM + Firebase) in a Swift project, and I want to be able to call some methods when tags are triggered. However, it doesn't seem to work with Swift, although similar implementations in Objective C and Android projects did work.
Here's the class conforming to the TAGCustomFunction protocol :
import Foundation
import GoogleTagManager
final class Tags: NSObject, TAGCustomFunction {
func execute(withParameters parameters: [AnyHashable : Any]!) -> NSObject! {
print("YEAH ! IT WORKS !")
return nil
}
}
Everything is working well, even though I see these kind of logs:
GoogleTagManager info: Processing logged event: applicationStart with parameters: (null)
But the log I'm printing is not showing…
I'm sure about the configuration of the container since this one is correctly loaded, and I use the exact same container for my Objective C project, in which it works perfectly.

Answer 1

I think TAGCustomFunction needs to have class/method #objc annotations, and the class-level #objc annotation needs to specify the class name, i.e.
import Foundation
import GoogleTagManager
#objc(Tags)
final class Tags: NSObject, TAGCustomFunction {
#objc func execute(withParameters parameters: [AnyHashable : Any]!) -> NSObject! {
print("YEAH ! IT WORKS !")
return nil
}
}

Answer 2

After reading this SO post, I suddenly remembered that a Swift project could embed some objective C classes.
The solution to my problem was ridiculously easy to set up once I realized that, eventhough I've never had to do it before.
I created a new Cocoa Touch Class like the following :
Here is the .m :
#import "MyCustomTagClass.h"
#import "MySwiftClass-Swift.h"
#implementation MyCustomTagClass
- (NSObject*)executeWithParameters:(NSDictionary*)parameters {
[MySwiftClass myMethod];
}
#end
And here is the .h :
#import <Foundation/Foundation.h>
#import <GoogleTagManager/TAGCustomFunction.h>
#interface MyCustomTagClass : NSObject <TAGCustomFunction>
- (NSObject*)executeWithParameters:(NSDictionary*)parameters;
#end
Note that I import a header for my Swift class, which is automatically generated by Xcode. Just add -Swift.h after the name of your class to import it, just as I did in the .m example above.
Last, but not least, update your Swift class with #objc annotations at class and method declaration lines :
import Foundation
#objc class MySwiftClass: NSObject {
//...
#objc static func myMethod() {
// do something...
}
}
I hope this helped !