Question

in one of my Rails 3 controllers I need to return jSON response with only couple of attributes on the model, so I used

respond_with foo_list :only => [:id, :name], :methods => []

but still in the resposne I see more than just these 2 attributes, I noticed that those undesirable attributes are actually dynamic attributes generated from the query select function:

foo_list = Foo.select("count(bar) as dattr1, sum(adafsd) as dattr2")....

is there a way to work around this? or I have to build the hash myself?

thanks!

Answer 1

The conventional way to do this is to use the #as_json method on ActiveRecord that automatically converts an object to it’s json representation.

You can override it with whatever attributes you want:

def as_json(options = {})
  # minimal
  if options[:minimal].present?
    {id: self.id, name: self.name }
  # default
  else
    super
  end
end

...

my_model = MyModel.find(...)
my_model.as_json 
my_model.as_json(:minimal)