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:
#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:
#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:
#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
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
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
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