Nitrogen (Erlang web framework) file upload and validators on other form elements

Question

I am using Nitrogen. And I have an #upload element together with a #textarea element. When a user presses the button to upload the file the #textarea also gets posted and I can receive it with wf:q/1 in the finish_upload_even/4 function. This is all good but I want to wire a #validator to the #textarea and cannot find the TriggerId to use. Am I misunderstanding something or is this functionality not obvious? Maybe even impossible as of now?

Turmeric

Show us your Nitrogen source code please so that we show you where to position the validator. – Roast

we need the source, you could be doing something perhaps the wrong way. – Roast