Uttering multiple messages in FormAction submit

Hello, Can someone help me understand how the dispatcher sends replies when the submit method of FormAction is executing? I would like to display a message right at the begging of this method, telling the user that the computations may take a while and then display the actual result. I tried calling utter_message() before the part that takes long but the message still displays only at the end (I supposed after the method returns??). How can i get this behaviour?

Rasa Open Source sends a POST HTTP request to the action server which executes the form. All dispatched responses is returned along with the results for the form (which results in the message being displayed at the end). Is there some way to split up the actions, so that you e.g. do

  • a short submit call + the utterance
  • run another action with the long running operations? (or do this in the background)

I think submission of the form followed by another action works just fine. Thanks