Receiving Fabric Component event on JS side

[brunoro]

I got my Android Fabric Component to be displayed correctly by following the fabric-native-components doc, and now I'm trying to fire a callback on JS side from my Kotlin ViewManager. For this, I'm using the react-native-menu repo as a reference, after seeing that this "Move to EventDispatcher instead of RCTEventEmitte" PR from @cortinico got merged.

Here's what I did so far:

In my ViewManager I register the bubbling event type. I verified through a debugger that this gets called when the MyKeyboard component mounts.

    override fun getExportedCustomBubblingEventTypeConstants(): MutableMap<String, Any> {
        return MapBuilder.of(
                "onPressKey",
                MapBuilder.of("phasedRegistrationNames", MapBuilder.of("bubbled", "onPressKey"))
        )

I send the event from the View. I verified that the eventName == "onPressKey".

    val event: Event<MyKeyboardEvent> = MyKeyboardEvent(
      UIManagerHelper.getSurfaceId(mReactContext),
      mViewTag,
      eventName,
      primaryCode,
      character
    )
    val dispatcher = UIManagerHelper.getEventDispatcherForReactTag(mReactContext, mViewTag)
    dispatcher?.dispatchEvent(event)

On the component spec I defined the props for my event:

interface NativeProps extends ViewProps {
  onPressKey: BubblingEventHandler<MyKeyboardEvent>;
}

And on the component declaration I attach a callback that never gets called:

<MyKeyboard onPressKey={onPressKey} />

Am I missing something? Are there any docs that I could use to check if some part is not setup correctly?

[brunoro]

Small update: I've stepped into the execution of the dispatchEvent call until it logged "Unable to invoke event: onPressKey for reactTag: -1" inside of FabricUIManager.receiveEvent`.

[brunoro]

The problem was that my reactTag was -1. I modified the way the event gets the reactTag and it worked fine.
The react-native-menu repo is the best reference I could find for implementing Fabric components so far.