SOLID In Rails - Open/Closed Principle

Software entities (classes, modules, functions, etc.) should be open for extension, but closed for modification

We have notification system

	class NotificationSender
	def send(user, message)
	EmailSender.send(user, message) if user.active?
	end
	end

view raw Solid-O01.rb hosted with ❤ by GitHub

But if we need to chose - send sms or email? So we can add something like if else, but the good way is to create another services
It's a way from Design Patterns.

	class Sender
	def send(user:, message:)
	raise NotImplementedError
	end
	end
	class EmailSender < Sender
	def send(user:, message:)
	# implementation for Email
	end
	end
	class SmsSender < Sender
	def send(user:, message:)
	# implementation for SMS
	end
	end
	sender = NotificationSender.new
	sender.send(user, "Hello World", SmsSender.new)

view raw Solid-O02.rb hosted with ❤ by GitHub

http://rubyblog.pro/