Паттерны проектирования 6.1

Паттерны Фабрика и Абстрактная фабрика.

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1. Паттерны проектирования часть 6.1
2. Фабрика Порождающий шаблон проектирования, позволяющий изменять поведение системы, варьируя создаваемые объекты, при этом сохраняя интерфейсы. Позволяет создавать целые группы взаимосвязанных объектов, которые, будучи созданными одной фабрикой, реализуют общее поведение.
3. Фабрика class Duck def initialize(name) @name = name end def eat puts("Duck #{@name} is eating.") end def speak puts("Duck #{@name} says Quack!") end def sleep puts("Duck #{@name} sleeps quietly.") end end
4. Фабрика class Pond def initialize(number_ducks) @ducks = [] number_ducks.times do |i| duck = Duck.new("Duck#{i}") @ducks << duck end end def simulate_one_day @ducks.each {|duck| duck.speak} @ducks.each {|duck| duck.eat} @ducks.each {|duck| duck.sleep} end end pond = Pond.new(3) pond.simulate_one_day
5. Фабрика class Frog def initialize(name) @name = name end def eat puts("Frog #{@name} is eating.") end def speak puts("Frog #{@name} says Crooooaaaak!") end def sleep puts("Frog #{@name} doesn't sleep; he croaks all night!") end end
6. Фабрика class Pond def initialize(number_animals) @animals = [] number_animals.times do |i| animal = new_animal("Animal#{i}") @animals << animal end end def simulate_one_day @animals.each {|animal| animal.speak} @animals.each {|animal| animal.eat} @animals.each {|animal| animal.sleep} end end class DuckPond < Pond def new_animal(name) Duck.new(name) end end
7. Фабрика
8. Фабрика class Algae def initialize(name) @name = name end def grow puts("The Algae #{@name} soaks up the sun and grows") end end class WaterLily def initialize(name) @name = name end def grow puts("The water lily #{@name} floats, soaks up the sun, and grows") end end
9. Фабрика class Pond def initialize(number_animals, number_plants) @animals = [] number_animals.times do |i| animal = new_animal("Animal#{i}") @animals << animal end @plants = [] number_plants.times do |i| plant = new_plant("Plant#{i}") @plants << plant end end def simulate_one_day @plants.each {|plant| plant.grow } @animals.each {|animal| animal.speak} @animals.each {|animal| animal.eat} @animals.each {|animal| animal.sleep} end end
10. Фабрика class DuckWaterLilyPond < Pond def new_animal(name) Duck.new(name) end def new_plant(name) WaterLily.new(name) end end class FrogAlgaePond < Pond def new_animal(name) Frog.new(name) end def new_plant(name) Algae.new(name) end end
11. Фабрика class Pond def initialize(number_animals, number_plants) @animals = [] number_animals.times do |i| animal = new_organism(:animal, "Animal#{i}") @animals << animal end @plants = [] number_plants.times do |i| plant = new_organism(:plant, "Plant#{i}") @plants << plant end end # ... end class DuckWaterLilyPond < Pond def new_organism(type, name) if type == :animal Duck.new(name) elsif type == :plant WaterLily.new(name) else raise "Unknown organism type: #{type}" end end end
12. class Pond def initialize(number_animals, animal_class, number_plants, plant_class) @animal_class = animal_class @plant_class = plant_class @animals = [] number_animals.times do |i| animal = new_organism(:animal, "Animal#{i}") @animals << animal end @plants = [] number_plants.times do |i| plant = new_organism(:plant, "Plant#{i}") @plants << plant end end def simulate_one_day @plants.each {|plant| plant.grow} @animals.each {|animal| animal.speak} @animals.each {|animal| animal.eat} @animals.each {|animal| animal.sleep} end def new_organism(type, name) if type == :animal @animal_class.new(name) elsif type == :plant @plant_class.new(name) else raise "Unknown organism type: #{type}" end end end
13. Абстрактная фабрика
14. Абстрактная фабрика class PondOrganismFactory def new_animal(name) Frog.new(name) end def new_plant(name) Algae.new(name) end end class JungleOrganismFactory def new_animal(name) Tiger.new(name) end def new_plant(name) Tree.new(name) end end
15. Абстрактная фабрика class Habitat def initialize(number_animals, number_plants, organism_factory) @organism_factory = organism_factory @animals = [] number_animals.times do |i| animal = @organism_factory.new_animal("Animal#{i}") @animals << animal end @plants = [] number_plants.times do |i| plant = @organism_factory.new_plant("Plant#{i}") @plants << plant end end # ... end jungle = Habitat.new(1, 4, JungleOrganismFactory.new) jungle.simulate_one_day pond = Habitat.new( 2, 4, PondOrganismFactory.new) pond.simulate_one_day
16. Абстрактная фабрика class OrganismFactory def initialize(plant_class, animal_class) @plant_class = plant_class @animal_class = animal_class end def new_animal(name) @animal_class.new(name) end def new_plant(name) @plant_class.new(name) end end jungle_organism_factory = OrganismFactory.new(Tree, Tiger) pond_organism_factory = OrganismFactory.new(WaterLily, Frog) jungle = Habitat.new(1, 4, jungle_organism_factory) jungle.simulate_one_day pond = Habitat.new( 2, 4, pond_organism_factory) pond.simulate_one_day
17. Абстрактная фабрика class IOFactory def initialize(format) @reader_class = self.class.const_get("#{format}Reader") @writer_class = self.class.const_get("#{format}Writer") end def new_reader @reader_class.new end def new_writer @writer_class.new end end html_factory = IOFactory.new('HTML') html_reader = html_factory.new_reader pdf_factory = IOFactory.new('PDF') pdf_writer = pdf_factory.new_writer