bash

ruby x.rb                                                                                                                              

{"title":"SHINY NEW TITLE","bar":"blah"}

x.rb

require 'json'

class Foo

  attr_accessor :title, :bar

  def initialize
    self.title = "shiny new title" 
    self.bar = "blah"
  end

  def html_attributes
   hash = {}
   instance_variables.each {|var| hash[var.to_s.delete("@")] = instance_variable_get(var) }
   hash.merge! "title" => title.upcase
   JSON.generate(hash)
  end

end

f = Foo.new
puts f.html_attributes