Question

I have two ActiceRecord classes:

class A < ActiveRecord::Base
  has_one :b
end

class B < ActiveRecord::Base
  belongs_to :a
end

How do I determine the object to which B is associated to when the associations between A and B are only initialized e.g. at runtime?

I am looking for something like this:

b.association => A

Answer 1

I’m not sure if this would help you but

B.reflections

…will give you a Hash of associations at class level. You could filter through those.

For example:

class Datastream < ActiveRecord::Base
  belongs_to :dashboard
end

Datastream.reflections
# outputs: {:dashboard=>#<ActiveRecord::Reflection::AssociationReflection:0x00000100e21ef8 @macro=:belongs_to, @name=:dashboard, @options={}, @active_record=Datastream(id: integer, dashboard_id: integer, position: integer, feed_id: string, stream_id: string, created_at: datetime, updated_at: datetime), @collection=false>}