You can now add an :inverse_of option to has_one, has_many and belongs_to associations. This is best described with an example:
class Man < ActiveRecord::Base
has_one :face, :inverse_of => :man
class Face < ActiveRecord::Base
belongs_to :man, :inverse_of => :face
m = Man.first
f = m.face
Without :inverse_of m and f.man would be different instances of the same object (f.man being pulled from the database again). With these new :inverse_of options m and f.man are the same in memory instance.
Currently :inverse_of supports has_one and has_many (but not the :through variants) associations. It also supplies inverse support for belongs_to associations where the inverse is a has_one and it's not a polymorphic.
Signed-off-by: Murray Steele <email@example.com>
Signed-off-by: Jeremy Kemper <firstname.lastname@example.org>