This isn’t a question – it’s just me being astonished by yet another
thing in Rails that Just Works. Here it is:
class Wizard < ActiveRecord::Base
before_create :create_deferrables
has_one :weather_loader, :as => :owner, :dependent => :destroy
def create_deferrables
self.create_weather_loader
end
end
class WeatherLoader < ActiveRecord::Base
belongs_to :owner, :polymorphic => true
end
I’d always assumed the above would NOT work because
Wizard#create_weather_loader gets called before the wizard had been
assigned an id, so how would WeatherLoader#owner_id get set?
And yet the architecture of relations is smart enough to know that when
it assigns an ID to the wizard that it needs to update the
weather_loader as well. (And since it’s a polymorphic association, it
automagically sets WeatherLoader#owner_type as well.)
IMHO, that’s chunky-bacon awesomeness. Thank you, Rails!