At the request of Kevin Marsh, the polymorphs plugin now supports single-table inheritance.
example
the sti base class
class Person < ActiveRecord::Base
endsti children
class Hipster < Person
end
class Groupie < Person
endthe collection parent class
class Concert < ActiveRecord::Base
has_many_polymorphs :concert_goers,
:from => [:hipsters, :groupies]
endThen you can do a_concert.concert_goers, a_concert.groupies, etc., and everything will work.
download
Get it here.
7 Comments
You made my day! Thanks very much, I’m going to try it out tonight and give you a full report.
Thanks again!
I think you are the smartest guy in the world!
How would you setup the scenario where Concert was also a STI table with RockConcert and JazzConcert as children?
So as the end result you can get
a_groupie.rock_concertsora_hipster.jazz_concerts.That would probably require an
acts_as_double_polymorphic_joinbetween both class sets.But really, if you’re using that much STI in your system, you’re probably doing it wrong.
Well I thought about using the
acts_as_double_polymorphic_join, but Concert is only STI and the type would always be the same in the join table, meaning ‘Concert’.Is there an easy way of getting the result without using the double polymorphic join?
You can use the regular
has_many_polymorphson the base class, but you’d have to write your own accessors for each child class. Aselect {|o| o.is_a? self.class }might do fine, but you’ll need to watch your DB to make sure you aren’t reloading data that is actually already available in the base association.Thank you for the quick replies. It’s not as straighforward as I thought. At the same time the thing I’m trying to accomplish is not very common. Great job with the plugin.