ad_set_thoughts.rb

# From Rails 3 ActiveSupport I believe
class StringInquirer < String
   def method_missing(method_name, *arguments)
     if method_name.to_s[-1,1] == "?"
       self == method_name.to_s[0..-2]
     else
       super
     end
   end
end

##
# Creates an adset capable of answering about positions in the set as methods.
# ` AdSet.new("top_rail).top_rail? => true`
# 
class AdSet < Array

    def initialize(*args)
      super(*args)
      self.map!{ |v| StringInquirer.new(v) }
      self
    end

    def <<(v)
      insert(0, StringInquirer.new(v))
    end

    alias push <<
    alias unshift <<

    def method_missing(method_name, *arguments)
      return self.any?{ |v| v.send(method_name) }
    end

end

cool_ad_set = AdSet.new(['top_rail','right_rail','header_text'])

puts "This AdSet #{cool_ad_set.inspect} contains top_rail? #{cool_ad_set.top_rail?}"
# => This AdSet ["top_rail", "right_rail", "header_text"] contains top_rail? true

puts "This AdSet #{cool_ad_set.inspect} contains random_thing? #{cool_ad_set.random_thing?}"
# => This AdSet ["top_rail", "right_rail", "header_text"] contains random_thing? false