testing controlled inclusiong

include.rb

class DataStore < Hash
	def store(key,value)
		self[key] = value
	end
end



module PropertyPlugin
	def self.included(base)
		base.extend(ClassMethods)
	end

	module ClassMethods
		def has_property_plugin
			include InstanceMethods
		end
	end

	module InstanceMethods
		attr_accessor :dstore

		def dstore
			@dstore ||= DataStore.new
		end

		def property(key,value)
			self[key] = value
		end

		def []=(key,value)
			dstore.store(key,value)
		end


	end
end

class A 
	include PropertyPlugin

	def write_property_greeting (subject)
		self[:hello] = subject if self.respond_to? :property
	end
end

class B < A 
	has_property_plugin

end

class C < A

end



[ B , C ].each do | c |
	puts c
	m = c.new
	m.write_property_greeting "world"

	if m.respond_to? :dstore
		puts "DataStore:\n---------------------------------------------------\n"
		m.dstore.each do |key, value|
			puts "#{key} => #{value}"
		end
		puts "---------------------------------------------------\n"
	else 
		puts " #{m.class} does not have a dStore"
	end
end