I would like to have an array saving fields to display for an object
that is used for its form on multiple pages.
I have declared the array in each of the controller methods that would
use it. Where can I put the array so that I only have to define it
once and then use it repeatedly on different pages?
You could always render that information in a partial so your object
always appears the same to the user no matter what form they are on.
Next implement view caching on that partial. No need to clutter up
session, pass around hidden fields, or necessarily hit the DB for each
display, just render the cached partial.