module ActiveModel::Serialization

def serializable_hash(options = nil)
  options ||= {}
  only   = Array.wrap(options[:only]).map(&:to_s)
  except = Array.wrap(options[:except]).map(&:to_s)
  attribute_names = attributes.keys.sort
  if only.any?
    attribute_names &= only
  elsif except.any?
    attribute_names -= except
  end
  method_names = Array.wrap(options[:methods]).inject([]) do |methods, name|
    methods << name if respond_to?(name.to_s)
    methods
  end
  (attribute_names + method_names).inject({}) { |hash, name|
    hash[name] = send(name)
    hash
  }
end