When playing aroung with the rest api I missed the feature to retrieve a list of all puppetclasses with their respective ids.

So, I alter the file app/controllers/puppetclasses_controller.rb to include a method to retrieve a json object with all classes with their ids.

def all
    @puppetclasses = Puppetclass.find(:all, :select => "id, name", :order => 'id').to_json
    render :json => @puppetclasses
  end

Then, in the router.rb file I add:

map.connect "/puppetclasses/all", :controller => 'puppetclasses', :action => 'all'

I am not a big ruby expert, so I don't know if this is the best approach... :)