gistfile1.txt

class Event < ActiveRecord

  has_many :charges do
  
    def self.total
      self.collect{|charge|charge.total}.sum
    end

  end

  has_many :transactions do

    def self.total
      self.collect{|charge|charge.total}.sum
    end

  end

  def underpaid?
    self.charges.total > self.transactions.total
  end

end