Observer pattern in ruby

Created quickly a couple of classes to show the observer pattern in Ruby .

	class Subject
	def initialize
	@name = "Subject1"
	p "Subect initialized to #{@name}"
	@observerList=Array.new #initialize the observer list
	end
	def name=(n)
	@name = n
	p "Subject's name changed to #{@name}"
	setChanged(); #indicate the object has been changed - that calls the publishing function
	notifyObservers
	end
	def addObserver(observer)
	if (defined?@observerList).nil? #if our observer array is damaged
	p "Some problem with observer list - no array defined"
	else
	@observerList[@observerList.length] = observer
	end
	end
	def setChanged
	@@changed = 0
	end
	def clearChanged
	@@changed = 1
	end
	def hasChanged?
	@@changed ||= 1
	end
	def notifyObservers
	if hasChanged?
	@observerList.each do |observerToNotify| #notify all the observers
	observerToNotify.update(@name)
	p "#{observerToNotify} has been updated"
	end
	clearChanged #notification complete
	p "Clear changed called.<end>"
	end
	end
	end
	class Observer
	def initialize
	@name = "Initial observer name"
	p @name
	end
	def update(name)
	@name = name
	p "Updated name in observer to #{@name}" #just for testing
	end
	end
	s1 = Subject.new
	o1 = Observer.new
	s1.addObserver(o1)
	s1.name="Arun"

view raw observer_ruby.rb hosted with ❤ by GitHub

Note : work to be done in finding the name of the object in the block under notifyObservers method.