datato the predicted value, when starting the async action. Once the action completes, it will update
datato the actual value, probably the same value as predicted.
deferFnat the same time. This allows you to combine data fetching with performing actions. A typical example of where this is useful is with forms, where you first want to populate the fields with current values from the database, and send the new values back when submitting the form. Do note that
deferFnoperate on the same
data, so they should both resolve to a similar kind of value.