View Code

registration.html.erb

<%= form_for(resource, url: registration_path(resource_name), method: :post) do |f| %>

  <% resource.contacts.each do |contact| %>
    <% f.fields_for :contact do |contact_fields| %>
      Nome: <%= contact_fields.text_field :name %>
    <% end %>
  <% end %>

  <div class="register-buttons">
    <%= f.submit "Finish", class: "button button-primary", data: { disable_with: "Finish" }  %>
  </div>
<% end %>

registration.rb

class Registration
  include ActiveModel::Model
    attr_accessor :contacts

    def initialize(customer, params = {})
      @contacts = [Contact.new, Contact.new]
      @customer = customer
      super(params)
    end
  end
end

registration_controller.rb

class RegistrationsController < Devise::RegistrationsController

  prepend_before_filter :authenticate_scope!, only: [:edit, :update, :destroy, :success_sign_up]

  def new; end

  def create
    @resource = Registration.new(customer, params)
  end
  
  def resource
    @resource ||= Registration.new(customer)
  end

  def success_sign_up; end

  # overriding sign up to work with form object instead directly with model
  def sign_up(resource_name, resource)
    sign_in(resource_name, resource.customer)
  end
  
  private
  def customer
    current_customer || Customer.new
  end
end