Hello all,

I've been trying to create a custom function in JavaScript for AdaptiveCards. See following code:

        Expression.functions.add("i18n", (args) => {
             if(args[0] !== null) {
                 let translationKey = args[0];
                 return i18nUtils().formatMessage({id: translationKey});
             } else {
                 return null;
             }
         });

Simply put, i give the function a name, pass a callback function in which I simply wanna translate a key and return its translated value. The translation on it's own works fine. But when trying to invoke this custom function, it says that "i18n" is an unknown function. I invoked this function right before the templateData gets initialized.

Funny thing is, when I search for this custom function, it is listed up along all other built-in functions.

I know there is a tutorial on how to implement this on C# but not in JavaScript. Did i do it the right way or do I need to change something?