How to create a field that is derived from other fields that are defined in the blueprint?

[sagexfors]

Suppose I have a Person model that has first, middle, and last name.

then i create a new field

:field full_name do |person, options|
  # concatenate the names
end

how to use the full_name field here?

:field full_name_and_id do |person, options|
  # full_name field that i defined above + id
  # person.full_name returns nomethod error
end

[sqlninja]

Any reason not to define the full_name method in your Person model? Then it would be accessible in your full_name_and_id field and could just defined as a regular field above...