80 lines
1.5 KiB
Ruby
80 lines
1.5 KiB
Ruby
|
# Abstract Factory patterns work around a super-factory which creates other
|
||
|
|
# factories. This factory is also called as factory of factories. This type of
|
||
|
|
# design pattern comes under creational pattern as this pattern provides one of
|
||
|
|
# the best ways to create an object.
|
||
|
|
|
||
|
|
# In Abstract Factory pattern an interface is responsible for creating a factory
|
||
|
|
# of related objects without explicitly specifying their classes. Each generated
|
||
|
|
# factory can give the objects as per the Factory pattern.
|
||
|
|
|
||
|
|
# Classes witch is used in abstract factories
|
||
|
|
|
||
|
|
class Frog
|
||
|
|
# Implementation
|
||
|
|
end
|
||
|
|
|
||
|
|
class Algae
|
||
|
|
# Implementation
|
||
|
|
end
|
||
|
|
|
||
|
|
class Tiger
|
||
|
|
# Implementation
|
||
|
|
end
|
||
|
|
|
||
|
|
class Tree
|
||
|
|
# Implementation
|
||
|
|
end
|
||
|
|
|
||
|
|
# Abstract factory with realization pond environment
|
||
|
|
class PondFactory
|
||
|
|
def new_animal
|
||
|
|
Frog.new
|
||
|
|
end
|
||
|
|
|
||
|
|
def new_plant
|
||
|
|
Algae.new
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
# Abstract factory with realization jungle environment
|
||
|
|
class JungleFactory
|
||
|
|
def new_animal
|
||
|
|
Tiger.new
|
||
|
|
end
|
||
|
|
|
||
|
|
def new_plant
|
||
|
|
Tree.new
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
# Factory of factories
|
||
|
|
class EnvironmentFactory
|
||
|
|
attr_reader :factories
|
||
|
|
|
||
|
|
def initialize
|
||
|
|
@factories = %w(PondFactory JungleFactory)
|
||
|
|
end
|
||
|
|
|
||
|
|
def get_factory(method)
|
||
|
|
factory_class = get_factory_class method
|
||
|
|
|
||
|
|
if factories.include? factory_class
|
||
|
|
self.class.const_get(factory_class).new
|
||
|
|
else
|
||
|
|
super
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
private
|
||
|
|
|
||
|
|
def get_factory_class(method)
|
||
|
|
"#{method.to_s.capitalize}Factory"
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
# Usage
|
||
|
|
environment = EnvironmentFactory.new
|
||
|
|
jungle = environment.get_factory(:jungle)
|
||
|
|
jungle.new_animal
|
||
|
|
|