aggregation: use composed_of with multiple classes (tables)

Does anyone know how to use composed_of to pull data from multiple classes (tables)? I know how to use composed_of to aggregate columns within the same table but am running in to trouble pulling from two tables.

The example below works but I don't want to see standard.strand_id, I want to see strand.name (which is in the Strand table, not the Standard table).

class Standard < ActiveRecord::Base   composed_of :full_standard,               :mapping =>                 [                   %w[grade grade],                   %w[strand_id strand_id]                   %w[number number]                 ]

class FullStandard < ActiveRecord::Base   attr_reader :grade, :strand_id, :number

  def initialize(grade, strand, number)     @grade = grade     @strand_id = strand_id     @number = number   end

  def to_s     [ @grade, @strand_id, @number ].compact.join(" ")   end end

Again, this works, BUT I don't want to see the strand_id, I want to see strand.name (a column in the Strand table--not the Standard table)

Also, here are the table relationships:

class Standard belongs_to :strand

class Strand has_many :standards

Thank you!!!

Is anyone able to share some insight regarding composed_of pulling from two tables?