Reference dates on a form

There is now a protected method in FormData called getLookupDate that determines the reference date to use for that form. The built-in class defines the standard implementation.

Individual form patterns can add their own implementation of the getLookupDate method in their forms inference class. For example, if a particular form is directly related to a particular coverage, the getLookupDate implementation for that form must return the reference date from the related coverage. In other words, you do not need to necessarily use the generic period-level reference date.

The built-in FormData.getLookupDate implementation gets the lookup date from coverages, which calls the IReferenceDatePlugin plugin implementation to get reference dates. However, IReferenceDatePlugin does not do anything specific to forms.