Trying to respect the law of demeter

gistfile1.rb

class User < ActiveRecord::Base
  belongs_to :account

  #A number of methods giving this class too many responsibilities already
end

class Account < ActiveRecord::Base
  # t.integer credits

  def add_credit(amount)
  def available_credit
  def deduct_credit(amount)

end

#The question is, is there any way to avoid writing code of the form "user.account.add_credit", and thus violating the law of demeter.

# For example:

def bill_user(user, amount)
  if user.account.available_credits > amount
    user.account.deduct_credits(amount)
  else
    #Charge user's credit card
  end
end

Say that we have a user class (above) with the typical problem of having too many responsibilities. We are trying to introduce the concept of "prepaid credits" so that when we bill a user instead of charging their # card, we can deduct credits instead. We want to add some methods like "add_credit" and "available_credits". We want to avoid adding these methods to User.

One idea I had was to create an Account object (see above), and define the methods on that.

The question is, is there any way to avoid writing code of the form "user.account.add_credit", and thus violating the law of demeter.