jordangraft

class Order < ActiveRecord::Base

    # again it needs to return an array of strings 
    def self.filter_names
        ['ssn', 'credit_card', 'password']
    end

end

jordangraft

class Order < ActiveRecord::Base

    # needs to return an array of strings representing method names that exist for the model
    def self.optional_csv_attributes
        ['state']
    end

    def state
        return 'the state'
    end

jordangraft

class Order < ActiveRecord::Base

    has_many :line_items

    def has_many_associations
      self.reflect_on_all_associations(:has_many).collect {|assoc| "#{assoc.name}_total_amount"}
    end

    def line_items_total_amount
        line_items.sum(:amount)

jordangraft

gem 'acts_as_csv', git: 'https://github.com/jordangraft/acts_as_csv.git', branch: 'stable-1.0'

jordangraft

Test