Ruby使用設計模式中的代理模式與裝飾模式的代碼執行個體_ruby專題

代理模式

需求：

小明讓小李替他追小麗（送洋娃娃，送花，送巧克力）

沒有代理的代碼：

# -*- encoding: utf-8 -*-#追求者類class Pursuit attr_accessor :mm  def initialize(mm)  @mm = mm end  def give_dolls  puts "#{mm.name} 送你洋娃娃" end  def give_flowers  puts "#{mm.name} 送你鮮花" end  def give_chocolate  puts "#{mm.name} 送你巧克力" endend#被追求者類class Girl attr_accessor :name  def initialize(name)  @name = name endendxiao_hong = Girl.new('小紅')xiao_ming = Pursuit.new(xiao_hong)xiao_ming.give_dollsxiao_ming.give_flowersxiao_ming.give_chocolate

只有代理的代碼：

# -*- encoding: utf-8 -*-#代理類class Proxy attr_accessor :mm  def initialize(mm)  @mm = mm end  def give_dolls  puts "#{mm.name} 送你洋娃娃" end  def give_flowers  puts "#{mm.name} 送你鮮花" end  def give_chocolate  puts "#{mm.name} 送你巧克力" endend#被追求者類class Girl attr_accessor :name  def initialize(name)  @name = name endendxiao_hong = Girl.new('小紅')xiao_ming = Proxy.new(xiao_hong)xiao_ming.give_dollsxiao_ming.give_flowersxiao_ming.give_chocolate

只是把追求者類換成了代理類。

實際的代理模式代碼：

# -*- encoding: utf-8 -*-#公用介面modulemodule GiveGift def give_dolls end  def give_flowers end  def give_chocolate endend#追求者類class Pursuit include GiveGift attr_accessor :mm, :name  def initialize(mm)  @mm = mm end  def give_dolls  puts "#{mm.name} 替#{name}送你洋娃娃" end  def give_flowers  puts "#{mm.name} 替#{name}送你鮮花" end  def give_chocolate  puts "#{mm.name} 替#{name}送你巧克力" endend#代理類class Proxy include GiveGift attr_accessor :gg  def initialize(mm)  @gg = Pursuit.new(mm) end  def give_dolls  gg.give_dolls end  def give_flowers  gg.give_flowers end  def give_chocolate  gg.give_chocolate endend#被追求者類class Girl attr_accessor :name  def initialize(name)  @name = name endendxiao_hong = Girl.new('小紅')xiao_ming = Proxy.new(xiao_hong)xiao_ming.gg.name = '小明'xiao_ming.give_dollsxiao_ming.give_flowersxiao_ming.give_chocolate

裝飾模式
 
需求：

給人搭配不同的服飾

代碼版本一

# -*- encoding: utf-8 -*-class Person attr_accessor :name  def initialize(name)  @name = name end  def wear_t_shirts  puts '大T恤' end  def wear_big_trouser  puts '垮褲' end  def wear_sneakers  puts '破球鞋' end  def wear_suit  puts '西裝' end  def wear_tie  puts '領帶' end  def wear_leather_shoes  puts '皮鞋' end  def show  puts "*****裝扮的#{name}\n\n" endendxc=Person.new('小菜')puts "******第一種裝扮"xc.wear_t_shirtsxc.wear_big_trouserxc.wear_sneakersxc.showputs "******第二種裝扮"xc.wear_suitxc.wear_tiexc.wear_leather_shoesxc.show

這樣寫的話，功能是實現了，問題是如果增加“超人”的裝扮，就要修改Person類，違反了開放-封閉原則。

 

代碼版本二

# -*- encoding: utf-8 -*-class Person attr_accessor :name  def initialize(name)  @name = name enddef show  puts "*****裝扮的#{name}\n\n" endendclass Finery def show endendclass TShirts < Finery def show  puts '大T恤' endendclass BigTrouser < Finery def show  puts '垮褲' endendclass Sneakers < Finery def show  puts '破球鞋' endendclass Suit < Finery def show  puts '西裝' endendclass Tie < Finery def show  puts '領帶' endendclass LeatherShoes < Finery def show  puts '皮鞋' endendxc=Person.new('小菜')ts = TShirts.newbt = BigTrouser.newsk = Sneakers.newputs "******第一種裝扮"ts.showbt.showsk.showxc.showsuit = Suit.newtie = Tie.newls = LeatherShoes.newputs "******第二種裝扮"suit.showtie.showls.showxc.show

這樣改了之後，如果增加超人裝扮，確實不需要去修改Person類。存在的問題是，各種衣服是獨立的，並且暴露在外邊的，就是一件一件穿的，沒有順序，沒有控制。

代碼版本三

# -*- encoding: utf-8 -*-class Person attr_accessor :name  def initialize(name=nil)  @name = name end  def show  puts "*****裝扮的#{name}\n\n" endendclass Finery < Person attr_accessor :componet def decorate(componet)  @componet = componet end def show  componet.show if componet endendclass TShirts < Finery def show  super  puts '大T恤' endendclass BigTrouser < Finery def show  super  puts '垮褲' endendclass Sneakers < Finery def show  super  puts '破球鞋' endendclass Suit < Finery def show  super  puts '西裝' endendclass Tie < Finery def show  super  puts '領帶' endendclass LeatherShoes < Finery def show  super  puts '皮鞋' endendxc=Person.new('小菜')ts = TShirts.newbt = BigTrouser.newsk = Sneakers.newputs "******第一種裝扮"ts.decorate xcbt.decorate tssk.decorate btsk.showsuit = Suit.newtie = Tie.newls = LeatherShoes.newputs "******第二種裝扮"suit.decorate xctie.decorate suitls.decorate btls.show