Question

In Rails 2.3 I have a Rails engine which has its own namespaced controllers, but which will use the main app’s models.

However, I want to override the default behavior of ActiveRecord::Base#to_json method but only when the model is being used from the Engine.

So in an Engine controller is it reasonable to do something like…

category.questions.each do |qst|
  # override ActiveRecord::Base#to_json somehow on the qst instance 
end

…if it is reasonable conceptually, how would I actually go about such a thing?

If it’s not reasonable, what is the best way to override ActiveRecord::Base#to_json for the Engine only, and not the main app?

Thanks,

Paul

Answer 1

You can do this using instance_eval:

category.questions.each do |qst|
  qst.instance_eval do
    # do something here
  end
end

However, I’m not sure if this is actually an appropriate strategy for what you want to do. A simpler approach would be to make a differently named method and use that in place of to_json in your engine.