gistfile1.rb

# orders.rb
scope :last_week, lambda { orders.where(purchased_at: 1.week.ago..Time.zone.now) }

# venue.rb
def timeline_summary
  [["LW", :last_week], ["LM", :last_month], ["4M", :4_months]].collect do |value|
    { label: value[0]
      value: self.orders.send(value[1]).count }
  end
end