attribute_method_prefix

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

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

to

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

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

class Person
  include ActiveModel::AttributeMethods

  attr_accessor :name
  attribute_method_prefix 'clear_'
  define_attribute_methods :name

  private
    def clear_attribute(attr)
      send("#{attr}=", nil)
    end
end

person = Person.new
person.name = 'Bob'
person.name          # => "Bob"
person.clear_name
person.name          # => nil