This is a class.

datatemplate.rb

  class DataTemplate
    attr_reader :data, :narrative
    
    attr_accessor :name, :address

    def initialize(data_hash)
      data_hash.each do |key, value|
        self.send("#{key}=", value)
      end
      @data = data_hash
      write_narrative
    end

    def write_narrative
      #user writes in what should happened next
      raise "There is no 'write_narrative' method."
    end

    def write(condition, klass_a, klass_b = nil)
      @narrative ||= []
      if condition
        @narrative << klass_a.new.generate
      elsif klass_b
        @narrative << klass_b.new.generate
      else
      end
    end

    def publish
      @narrative.join(" ")
    end

  end
end