Ruby使用设计模式中的代理模式与装饰模式的代码实例
作者：范孝鹏
这篇文章主要介绍了Ruby使用设计模式中的代理模式与装饰模式的代码实例,代理模式与装饰模式都可以归类为结构型的设计模式,需要的朋友可以参考下
代理模式
需求：
小明让小李替他追小丽（送洋娃娃，送花，送巧克力）
没有代理的代码：
# -*- encoding: utf-8 -*-
#追求者类
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} 送你鲜花"
end
def give_chocolate
puts "#{mm.name} 送你巧克力"
end
end
#被追求者类
class Girl
attr_accessor :name
def initialize(name)
@name = name
end
end
xiao_hong = Girl.new('小红')
xiao_ming = Pursuit.new(xiao_hong)
xiao_ming.give_dolls
xiao_ming.give_flowers
xiao_ming.give_chocolate
只有代理的代码：
# -*- encoding: utf-8 -*-
#代理类
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} 送你鲜花"
end
def give_chocolate
puts "#{mm.name} 送你巧克力"
end
end
#被追求者类
class Girl
attr_accessor :name
def initialize(name)
@name = name
end
end
xiao_hong = Girl.new('小红')
xiao_ming = Proxy.new(xiao_hong)
xiao_ming.give_dolls
xiao_ming.give_flowers
xiao_ming.give_chocolate
只是把追求者类换成了代理类。
实际的代理模式代码：
# -*- encoding: utf-8 -*-
#公共接口module
module GiveGift
def give_dolls
end
def give_flowers
end
def give_chocolate
end
end
#追求者类
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}送你鲜花"
end
def give_chocolate
puts "#{mm.name} 替#{name}送你巧克力"
end
end
#代理类
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
end
end
#被追求者类
class Girl
attr_accessor :name
def initialize(name)
@name = name
end
end
xiao_hong = Girl.new('小红')
xiao_ming = Proxy.new(xiao_hong)
xiao_ming.gg.name = '小明'
xiao_ming.give_dolls
xiao_ming.give_flowers
xiao_ming.give_chocolate
装饰模式
需求：
给人搭配不同的服饰
代码版本一
# -*- 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 '垮裤'
end
def wear_sneakers
puts '破球鞋'
end
def wear_suit
puts '西装'
end
def wear_tie
puts '领带'
end
def wear_leather_shoes
puts '皮鞋'
end
def show
puts "*****装扮的#{name}\n\n"
end
end
xc=Person.new('小菜')
puts "******第一种装扮"
xc.wear_t_shirts
xc.wear_big_trouser
xc.wear_sneakers
xc.show
puts "******第二种装扮"
xc.wear_suit
xc.wear_tie
xc.wear_leather_shoes
xc.show
这样写的话，功能是实现了，问题是如果增加“超人”的装扮，就要修改Person类，违反了开放-封闭原则。
代码版本二
# -*- encoding: utf-8 -*-
class Person
attr_accessor :name
def initialize(name)
@name = name
enddef show
puts "*****装扮的#{name}\n\n"
end
end
class Finery
def show
end
end
class TShirts < Finery
def show
puts '大T恤'
end
end
class BigTrouser < Finery
def show
puts '垮裤'
end
end
class Sneakers < Finery
def show
puts '破球鞋'
end
end
class Suit < Finery
def show
puts '西装'
end
end
class Tie < Finery
def show
puts '领带'
end
end
class LeatherShoes < Finery
def show
puts '皮鞋'
end
end
xc=Person.new('小菜')
ts = TShirts.new
bt = BigTrouser.new
sk = Sneakers.new
puts "******第一种装扮"
ts.show
bt.show
sk.show
xc.show
suit = Suit.new
tie = Tie.new
ls = LeatherShoes.new
puts "******第二种装扮"
suit.show
tie.show
ls.show
xc.show
这样改了之后，如果增加超人装扮，确实不需要去修改Person类。存在的问题是，各种衣服是独立的，并且暴露在外边的，就是一件一件穿的，没有顺序，没有控制。
代码版本三
# -*- encoding: utf-8 -*-
class Person
attr_accessor :name
def initialize(name=nil)
@name = name
end
def show
puts "*****装扮的#{name}\n\n"
end
end
class Finery < Person
attr_accessor :componet
def decorate(componet)
@componet = componet
end
def show
componet.show if componet
end
end
class TShirts < Finery
def show
super
puts '大T恤'
end
end
class BigTrouser < Finery
def show
super
puts '垮裤'
end
end
class Sneakers < Finery
def show
super
puts '破球鞋'
end
end
class Suit < Finery
def show
super
puts '西装'
end
end
class Tie < Finery
def show
super
puts '领带'
end
end
class LeatherShoes < Finery
def show
super
puts '皮鞋'
end
end
xc=Person.new('小菜')
ts = TShirts.new
bt = BigTrouser.new
sk = Sneakers.new
puts "******第一种装扮"
ts.decorate xc
bt.decorate ts
sk.decorate bt
sk.show
suit = Suit.new
tie = Tie.new
ls = LeatherShoes.new
puts "******第二种装扮"
suit.decorate xc
tie.decorate suit
ls.decorate bt
ls.show