customer.rb

来自「本书源码对于学习RUBY网络编程语言非常有帮助。」· RB 代码 · 共 61 行

class Customer < ActiveRecord::Base
  has_many :orders,
           :dependent => true,
           :order     => "created_at ASC"

  def open_orders
    orders.find(:all, :conditions => "status = 'open'")
  end

  def editions_on_order
    open_orders.map {|order| order.edition }.uniq
  end

  def edition_history
    orders.map {|order| order.edition }.uniq
  end

  def works_on_order
    editions_on_order.map {|edition| edition.works }.flatten.uniq
  end

  def work_history
    edition_history.map {|edition| edition.works }.flatten.uniq
  end

  def copies_of(edition)
    open_orders.select {|order| order.edition == edition } .size
  end

  def balance
    editions_on_order.inject(0) {|acc,edition| acc += edition.price }
  end

  def check_out
    orders.each do |order|
      order.update_attributes(:status => "paid")
    end
  end

  def rank(list)
    list.uniq.sort_by do |a|
      list.select {|b| a == b }.size
    end.reverse
  end

  def composer_rankings
    rank(edition_history.map {|ed| ed.composers }.flatten)
  end

  def instrument_rankings
    rank(work_history.map {|work| work.instruments }.flatten)
  end

  def favorites(thing,options)
    limit = options[:count]
    rankings = send("#{thing}_rankings")
    return rankings[0,limit].compact
  end

end