How to build a JSON response made up of multiple models in Rails

Question

First, the desired result

I have User and Item models. I\'d like to build a JSON response that looks like this:

{
  \"use         


        

Answer 1

EDITED to use as_json instead of to_json. See How to override to_json in Rails? for a detailed explanation. I think this is the best answer.

You can render the JSON you want in the controller without the need for the helper model.

def observe
  respond_to do |format|
    format.js do
      render :json => {
        :user => current_user.as_json(:only => [:username], :methods => [:foo, :bar]),
        :items => @items.collect{ |i| i.as_json(:only => [:id, :name], :methods => [:zim, :gir]) }
      }
    end
  end
end

Make sure ActiveRecord::Base.include_root_in_json is set to false or else you'll get a 'user' attribute inside of 'user'. Unfortunately, it looks like Arrays do not pass options down to each element, so the collect is necessary.