Migrating Applicative Form to Monadic - get current timestamp

Question

I have a working applicative form, but I want to add a textField that doesn't correspond to any field in my model. Everything is working okay except for one field. Part of my model is a UTCTime value that represents the timestamp of uploading. With applicative forms I had the following code:

-- some stuff
<*> aformM (liftIO getCurrentTime)
-- more stuff

and I can't seem to find the equivalent to aformM for monadic forms. I tried the following:

(timeRes, timeView) <- mformM (liftIO getCurrentTime)

hoping that there would be an equivalent function for monadic forms, similarly to how we have areq/mreq, aopt/mopt, etc., but my code wouldn't compile. So, my question is: is there a way to get the current timestamp using monadic forms?

Answer 1

usually an update timestamp doesn't require to be shown, so in an MForm monad you just pick the value and add it to the applicative result.

   currentTime <- liftIO getCurrentTime

   (field1_Res, field1_View) <- mreq ...

   let  myRecord_Res = MyRecord <$> pure currentTime <*> field1_Res <*> field2_Res <*> ...