How do I submit a boolean parameter in Rails?

UPDATE: Rails 5:

ActiveRecord::Type::Boolean.new.deserialize('0')

UPDATE: Rails 4.2 has public API for this:

ActiveRecord::Type::Boolean.new.type_cast_from_user("0") # false

PREVIOUS ANSWER:

ActiveRecord maintains a list of representations for true/false in https://github.com/rails/rails/blob/master/activerecord/lib/active_record/connection_adapters/column.rb

2.0.0-p247 :005 > ActiveRecord::ConnectionAdapters::Column.value_to_boolean("ON")
2.0.0-p247 :006 > ActiveRecord::ConnectionAdapters::Column.value_to_boolean("F")

This is not part of Rails’ public API, so I wrapped it into a helper method:

class ApplicationController < ActionController::Base
  private

  def parse_boolean(value)
    ActiveRecord::ConnectionAdapters::Column.value_to_boolean(value)
  end
end

and added a basic test:

class ApplicationControllerTest < ActionController::TestCase
  test "parses boolean params" do
    refute ApplicationController.new.send(:parse_boolean, "OFF")
    assert ApplicationController.new.send(:parse_boolean, "T")
  end
end