Extract Class Step Four

* Move another method
* Wrap up compound condition
* Privatize methods only used internally in new class

example_app/app/controllers/invitations_controller.rb

@@ -1,13 +1,13 @@
class InvitationsController < ApplicationController
  def new
    @survey = Survey.find(params[:survey_id])
    @survey_inviter = SurveyInviter.new('')
    @survey_inviter = SurveyInviter.new('', '')
  end

  def create
    @survey = Survey.find(params[:survey_id])
    @survey_inviter = SurveyInviter.new(recipients)
    if valid_recipients? && valid_message?
    @survey_inviter = SurveyInviter.new(message, recipients)
    if @survey_inviter.valid?
      recipient_list.each do |email|
        invitation = Invitation.create(
          survey: @survey,
@@ -27,14 +27,6 @@ def create

  private

  def valid_recipients?
    invalid_recipients.empty?
  end

  def valid_message?
    message.present?
  end

  def invalid_recipients
    @survey_inviter.invalid_recipients
  end

example_app/app/models/survey_inviter.rb

@@ -1,10 +1,15 @@
class SurveyInviter
  EMAIL_REGEX = /\A([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})\z/

  def initialize(recipients)
  def initialize(message, recipients)
    @message = message
    @recipients = recipients
  end

  def valid?
    valid_message? && valid_recipients?
  end

  def invalid_recipients
    @invalid_recipients ||= recipient_list.map do |item|
      unless item.match(EMAIL_REGEX)
@@ -16,4 +21,14 @@ def invalid_recipients
  def recipient_list
    @recipient_list ||= @recipients.gsub(/\s+/, '').split(/[\n,;]+/)
  end

  private

  def valid_message?
    @message.present?
  end

  def valid_recipients?
    invalid_recipients.empty?
  end
end