rails model attributes without corresponding column in db

Question

I have some rails models which don't need any persistence, however I'd like rails to think the model actually has attributes x, y, z so when calling methods like to_json in the controller I get them included for free.

For example,

class ModelWithoutTableColumns << ActiveRecord::Base

def x
   return "Custom stuff here"
end

There is no column x in the database for Table "ModelWithoutTable" (sorry for the slightly confusing name!)

Anyone have an idea how to tackle this one?

Answer 1

Just don't inherit from ActiveRecord::Base

Edit: Have you tried passing options to to_json, like :methods perhaps? See here

Answer 2

That won't work--ActiveRecord::Base defines to_json, but requires a table.

You should check out the ActiveRecord::BaseWithoutTable plugin. Here's how to use it, and here's an updated version for Rails 2.

I haven't tried either of them, so no guarantees.

Answer 3

You might also want to check out acts_without_database, the current details about it are here, but the site is down at the moment. Here's the posting on RubyFlow, it's from today.