polymorphic association helpers, now with twice the helpfulness

July 12, 2006 By in Uncategorized 2 Comments

I extensively updated my polymorphic has_many :through association helper plugin, and it’s worth a second look. You now get snazzy _push() and _delete() methods on the polymorphic collection:

example
petfood = Petfood.find(1)
petfood.eaters.map(&:class) # => [Dog, Cat, Cat, Bird]

petfood.eaters_push(Cat.create)
petfood.reload
petfood.cats.size # => 3
petfood.eaters.size # => 5

petfood.eaters_delete(petfood.dogs[0])
petfood.reload
petfood.dogs.size # => 0
petfood.eaters.size # => 4

# works both ways
petfood.eaters[0].petfoods.include?(petfood) # => true

And configuration is easier than even regular ActiveRecord:

usage
class Petfood < ActiveRecord::Base
  has_many_polymorphs :eaters, :from => [:dogs, :cats, :birds]
end

class EatersPetfood < ActiveRecord::Base
  belongs_to :petfood
  belongs_to :eater, :polymorphic => true
end

class Dog < ActiveRecord::Base
end

For more information and the plugin itself, go here.

2 responses

  1. Yer blog layout is a bit messed up. The post content is displayed at the top of the page above your page header.