app/controllers/profile_fields_controller.rb
require_dependency YourPlatform::Engine.root.join('app/controllers/profile_fields_controller').to_s
module ProfileFieldsControllerModifications
private
def profile_field_params
params.fetch(:profile_field, {}).permit(*(super.keys + [:wingolfspost]))
end
end
class ProfileFieldsController
prepend ProfileFieldsControllerModifications
end