league_rankings.rb

# The main class
class League < ActiveRecord::Base
  belongs_to :season
  belongs_to :country
  has_many :teams
  has_many :games

  def classify
    teams.sort_by([:points, :goalaverage]).reverse
  end
end

# Let's say that I create a League called "Strange"
# In this League the teams are ranked by their names
# I would like this League to extand the following Module
# So that I can call League.find(X).classify 
# and have a classifying method per League.

module StangeLeague
 def classify
    teams.sort_by([:name])
  end
end


# The 2 questions are :
# Is it the good way to do this
# If Yes, where and how should I call the extend method ?