attribute_method_suffix

Declares a method available for all attributes with the given suffix. Uses method_missing and respond_to? to rewrite the method.

#{attr}#{suffix}(*args, &block) 

to

attribute#{suffix}(#{attr}, *args, &block) 

An attribute#{suffix} instance method must exist and accept at least the attr argument.

class Person include ActiveModel::AttributeMethods attr_accessor :name attribute_method_suffix '_short?' define_attribute_methods :name private def attribute_short?(attr) send(attr).length < 5 end end person = Person.new person.name = 'Bob' person.name # => "Bob" person.name_short? # => true