filtering columns for test responses (probably too ugly warning)

PUBLIC_COLUMNS = %w(subdomain created_on updated_on company_name)

def output(data)

      if data.is_a? Array
        data = data.collect{ |d| hash_for(d) }
      else
        data = hash_for(data)
      end

      respond_to do |format|
        format.html { render :text => "
#{data.to_yaml}
" }
        format.xml  { render :xml  => data.to_xml }
        format.yaml { render :xml  => data.to_yaml }
        format.json { render :json => data.to_json }
      end
    end   

    def hash_for(record, fields = nil)
      r = {}
      fields ||= record.class::PUBLIC_COLUMNS
      fields.each do |f| 
        v = record.send(f)
        if v.is_a?(ActiveRecord::Base)
          r[f] = hash_for(v)
        elsif v.is_a?(Array)
          r[f] = v.collect{|i| hash_for(i)}
        else
          r[f] = record.send(f)
        end
      end
      r
    end

def index
    output MyModel.find(:all)
  end