Some kind of polymorphism

msmsms · February 8, 2009, 7:56pm

Hello out there,

let’s assume, I’ve got an article model. An article always has an
author and refers to it. But I’ve got several types of authors which
all have theier own models. So a simple foreign key rather belongs_to
will not help me. So, I could save the author_id and a kind of
authot_type to manually create the association. Is there a more
comfortable way in rails?

Thank you very much!
ms

msmsms · February 8, 2009, 8:02pm

Read this:
http://wiki.rubyonrails.org/rails/pages/polymorphicassociations

Maurício Linhares
http://alinhavado.wordpress.com/ (pt-br) | http://blog.codevader.com/
(en)

msmsms · February 8, 2009, 8:09pm

class Article < ActiveRecord::Base
belongs_to :author, :polymorphic => true
end

And then to assign an author:

article = Article.new
article.author = some_author
article.save

Maurício Linhares
http://alinhavado.wordpress.com/ (pt-br) | http://blog.codevader.com/
(en)

msmsms · February 8, 2009, 8:07pm

Thank you for your answer. I read this article before, but I can’t map
this technique to my problem. Maybe you can help me with this?

Thank you!

msmsms · February 8, 2009, 8:19pm

class Article < ActiveRecord::Base
belongs_to :author, :polymorphic => true
end

And then to assign an author:

article = Article.new
article.author = some_author
article.save

But I’ve got no no author model, since author is nothing concrete in
my data model. Doesn’t this matter?