Using GTM v5 TAGCustomFunction in Swift

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, ie

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 !