Create a template rendering class with ERB | http://garethrees.co.uk/2014/01/12/create-a-template-rendering-class-with-erb/

welcome_message.rb

class WelcomeMessage < ERB

  def self.template
    "Welcome, <%= @name %>"
  end

  def initialize(name, options = {})
    @name     = name
    @template = options.fetch(:template, self.class.template)
    super(@template)
  end

  def result
    super(binding)
  end

end