Rails: has_many through with polymorphic association - will this work?

Question

A Person can have many Events and each Event can have one polymorphic Eventable record. How do I specify the relationship between the Person and the Eventable record?

Here are the models I have:

class Event < ActiveRecord::Base   belongs_to :person   belongs_to :eventable, :polymorphic => true end  class Meal < ActiveRecord::Base   has_one :event, :as => eventable end  class Workout < ActiveRecord::Base   has_one :event, :as => eventable end 

The main question concerns the Person class:

class Person < ActiveRecord::Base   has_many :events   has_many :eventables, :through => :events  # is this correct??? end 

Do I say has_many :eventables, :through => :events like I did above?

Or do I have to spell them all out like so:

has_many :meals, :through => :events has_many :workouts, :through => :events 

If you see an easier way to accomplish what I'm after, I'm all ears! :-)

Answer 1

You have to do:

class Person < ActiveRecord::Base   has_many :events   has_many :meals, :through => :events, :source => :eventable,     :source_type => "Meal"   has_many :workouts, :through => :events, :source => :eventable,     :source_type => "Workout" end 

This will enable you to do this:

p = Person.find(1)  # get a person's meals p.meals.each do |m|   puts m end  # get a person's workouts p.workouts.each do |w|   puts w end  # get all types of events for the person p.events.each do |e|   puts e.eventable end